The Wellness industry includes fitness, sleep and activity, preventative care, and ultimately healthcare. It’s an industry that generates highly private information that can be used to the owner’s advantage when shared with wellness professionals, but which also can (and has) been used to its owner’s disadvantage in multiple situations.
Thus, the need for privacy-protecting data formats such as Gordian Envelope. This allows a holder of wellness information to elide and encrypt that data, so that only the minimal necessary information goes out, and only to the appropriate people. The ability to create multipermits for different people can also be highly useful in the complex wellness environment.
Ultimately, Wellness software can use Gordian Envelopes to:
- Ensure data is safe.
- Prevent data from being used to incriminate users.
- Transfer different subsets of data to different people.
- Encrypt different data for different people.
- Anonymize data for clinical trials and other public health initiatives.
- In doing so, also simplify HIPAA requirements.
Health Care Use Case Table of Contents
The following set of use cases demonstrates how to use Gordian Emvelope to store and share wellness data. Individual cases are presented progressively: each use case within a section builds on the previous onne by demonstrating a new capability. All use cases refer to Nadia, an activity tracker user. The first set describes how the tracker can protect data; the second set describes how it can allow Nadia to share that data with individuals in her wellness team; and the third set describes how she can also share that data to support public health. A final use case discusses some of the special challenges that rose up concerning contact tracing during the COVID pandemic.
Gordian Envelopes are useful for wellness because of their precise ability to elide and encrypt information, allowing for crucial data minimization when sharing some of the most personal data that a person can possess.
- Part One: Personal Sensor Data
- Part Two: Personal Shared Sensor Data
- Part Three: Clinically Shared Sensor Data
- Part Four: The COVID-19 Appendix
Part One: Personal Sensor Data
This first set of use cases describes the data format of Nadia’s new wearable activity tracker, the ToneZone, which is focused on keeping her data private.
1. Nadia Gets Fit (Metadata)
- Use Case: Nadia need a wearable activity tracker that can store her data.
- Openness Benefits: ToneZone uses a self-describing format that ensures that Nadia’s data will be readable in the far future.
Nadia has used wearable activity trackers for years, but she’s slowly become aware that she’s playing with fire. She’s storing away high levels of very personal data about her health and her location, and she has no assurance that any of the data is actually safe and secure. As a result, Nadia decides to purchase a new privacy-focused activity tracker, the ToneZone. Its main priority is securing data (with a secondary priority of sharing that data as its user sees fit, but that issue is down the road a bit).
The ToneZone’s data format is designed using Gordian Envelope, which allows for the encoding of tiered data laid out as assertions. The format was laid out not just as a simple-to-use structure, but also a structure that allows for the individual selection (and elision) of specific data:
"ur:cid/hdcxzoqzispesnbbkohddwbyhtbzzsssdldassamdeeofdtndsaazsjpdtnnvwfnatglbgbnehwe" [
"account": {
"00000001" [
"birthdate": "19891109"
"fullName": "Nadia Levedeva"
"height": "65.1"
"weight": "132.7"
]
}
"device": {
"ToneZone 1.0" [
"gpsInfoFor": "20230516" [
"gpsQueue": "1684274400" [
"distance": "0"
"latitude": "2.122778"
"longitude": "41.380833"
"status": "0"
]
"gpsQueue": "1684279978" [
"distance": "5230"
"latitude": "2.456944"
"length": "36000"
"longitude": "41.430278"
"status": "8"
]
]
"heartInfoFor": "20230515" [
"1684274400": "59"
"1684274460": "60"
"1684274520": "60"
"1684274580": "59"
"1684274640": "59"
]
"heartInfoFor": "20230516" [
"1684274400": "85"
"1684274460": "87"
"1684274520": "91"
"1684274580": "90"
"1684274640": "88"
]
"serialNumber": "SN102313A"
"statsFor": "20230515" [
"floors": "3"
"restingHeartRate": "55"
"steps": "5703"
"zoneMinutes": "0"
]
"statsFor": "20230516" [
"floors": "17"
"restingHeartRate": "56"
"steps": "10715"
"zoneMinutes": "25"
]
"stepInfoFor": "20230515" [
"1684188000": "0"
"1684188060": "0"
"1684188120": "7"
"1684188180": "2"
"1684188240": "0"
]
"stepInfoFor": "20230516" [
"1684274400": "95"
"1684274460": "99"
"1684274520": "103"
"1684274580": "103"
"1684274640": "101"
]
"tempInfoFor": "20230515" [
"1684188000": "97"
"1684188060": "97.1"
"1684188120": "97.3"
"1684188180": "97.2"
"1684188240": "97.1"
]
"tempInfoFor": "20230516" [
"1684274400": "98.2"
"1684274460": "98.2"
"1684274520": "98.3"
"1684274580": "98.2"
"1684274640": "98.2"
]
]
}
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
]
See the mermaid output.
This data structure includes not just device data from the ToneZone, but also personal account information that Nadia entered when she set up her ToneZone account, providing context for her wearable data.
The device data is divided among several categories and also for
individual days. This will make it easy for Nadia in the future to
differentiate highly personal data (such as gpsInfoFor and
unfortunately tempInfoFor) and more general data (such as
statsFor) and also to do it on a granular, daily basis. Obviously,
the actual ToneZone tracker will have lots more data both total and
for each day. This is just a cut-down example intended to show some of
the functionality possible.
Notably, the entire data structure is cleanly self-describing. The Gordian Envelope assertions clearly denote each type of data, while some data is additionally stored as a Uniform Resource (UR), which is also self-describing and built atop dCBOR, yet another self-describing format. Basically, it’s self-describing all the way down, ensuring the data’s openness, which will be vital when Nadia goes beyond the protection built into the ToneZone to allow some sharing of data (in Parts Two, Three, and Four).
2. Nadia Protects Her Privacy (Encryption)
- Use Case: Nadia wants to tracker data that isn’t easily accessible by unauthorized parties.**
- Privacy Benefits: Encryption ensures that the ToneZone data is closely protected on a few devices.
Of course, just formatting the data in a open manner isn’t enough. For Nadia’s ToneZone to fulfill its core goal, the data has to be protected.
This is simple with Gordian Envelope. The ToneZone creates “wrapped envelopes” that encrypt Nadia’s device data and account info. That data can only be decrypted with Nadia’s symmetric key, which is only stored on the ToneZone device and on its mobile app – nowhere else.
"ur:cid/hdcxzoqzispesnbbkohddwbyhtbzzsssdldassamdeeofdtndsaazsjpdtnnvwfnatglbgbnehwe" [
"account": ENCRYPTED
"device": ENCRYPTED
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
]
graph LR
1(("4f3ced9e<br/>NODE"))
2["426f3f8a<br/>#quot;ur:cid/hdcxzoqzispesnbbkohddwbyhtbzzsssd…#quot;"]
3(["38cadd4f<br/>ASSERTION"])
4["bb751b0e<br/>#quot;hasPubKey#quot;"]
5["2ada5820<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxtkzsswongh…#quot;"]
6(["c75e3bff<br/>ASSERTION"])
7["a05e2863<br/>#quot;account#quot;"]
8>"f1bfd553<br/>ENCRYPTED"]
9(["cac8aa12<br/>ASSERTION"])
10["52b252a6<br/>#quot;device#quot;"]
11>"a6e75627<br/>ENCRYPTED"]
1 -->|subj| 2
1 --> 3
3 -->|pred| 4
3 -->|obj| 5
1 --> 6
6 -->|pred| 7
6 -->|obj| 8
1 --> 9
9 -->|pred| 10
9 -->|obj| 11
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:#55f,stroke-width:3.0px
style 6 stroke:red,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 9 stroke:red,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px
style 11 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke:green,stroke-width:2.0px
linkStyle 3 stroke:#55f,stroke-width:2.0px
linkStyle 4 stroke-width:2.0px
linkStyle 5 stroke:green,stroke-width:2.0px
linkStyle 6 stroke:#55f,stroke-width:2.0px
linkStyle 7 stroke-width:2.0px
linkStyle 8 stroke:green,stroke-width:2.0px
linkStyle 9 stroke:#55f,stroke-width:2.0px
Note by comparing with the unencrypted mermaid
diagram that the checksums for the
encrypted data remains consistent. The account assertion is still
c75e3bff, the device assertion is still cac8aa12 and the master
checksum is still 4f3ced9e. This is a crucial technique within
Gordian, because it ensures that if data is signed, it can still be
validated even when encrypted or elided.
Thus the first goal of Nadia’s new tracker, ensuring privacy, is fulfilled!
3. Nadia Protects Her Key (SSKR)
- Use Case: Nadia needs to ensure that her private key isn’t a Single Point of Failure (SPOF) for her data!
- Openness Benefits: Using an open-sharding system, Nadia’s key can be recovered easily.
- Resilience Benefits: SSKR allows Nadia to remove her SPOF while keeping her key secure.
Though it’s great that Nadia can protect her personal data with a key that she holds, it can also be a Single Point of Failure (SPOF). If she loses her key, she loses her data.
Fortunately, the solution is easy with Gordian Envelope: create an envelope with the symmetric key, then lock that envelope with a multipermit so that it can either be recovered by Nadia using her private key or by putting together any two shares. The ToneZone uses this technique to create robust storage mechanism for Nadia’s key that could be improved any further by a system such as CSR, which could automate authentication and reconstruction.
Here’s the original envelope for the symmetric key::
"ur:crypto-key/hdcxvaftbypkwlstdsaabefgnbsfmnclctlohdhnplimdphyqdpakibejyemkofmyabtghftntfr"
graph LR
1["e487b47f<br/>#quot;ur:crypto-key/hdcxvaftbypkwlstdsaabefgnb…#quot;"]
style 1 stroke:#55f,stroke-width:3.0px
Here’s what it looks like after it’s been encrypted with Nadia’s public key and sharded:
ENCRYPTED [
hasRecipient: SealedMessage
sskrShare: SSKRShare
]
ENCRYPTED [
hasRecipient: SealedMessage
sskrShare: SSKRShare
]
ENCRYPTED [
hasRecipient: SealedMessage
sskrShare: SSKRShare
]
We’ll return to the topic of a multipermit in the future, but
essentially it enables an Envelope to be opened in multiple ways.
Here, the hasRecipient: allows Nadia to recover from any of the
three shares using her private key, while the sskrShare: allows
anyone to combine any two shares to recover the envelope.
graph LR
1(("071dafc7<br/>NODE"))
2>"304b2acb<br/>ENCRYPTED"]
3(["37de4479<br/>ASSERTION"])
4[/"7a4d6af9<br/>6"/]
5["b971727b<br/>SSKRShare"]
6(["9d790543<br/>ASSERTION"])
7[/"e41178b8<br/>5"/]
8["48208528<br/>SealedMessage"]
1 -->|subj| 2
1 --> 3
3 -->|pred| 4
3 -->|obj| 5
1 --> 6
6 -->|pred| 7
6 -->|obj| 8
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:#55f,stroke-width:3.0px
style 6 stroke:red,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke:green,stroke-width:2.0px
linkStyle 3 stroke:#55f,stroke-width:2.0px
linkStyle 4 stroke-width:2.0px
linkStyle 5 stroke:green,stroke-width:2.0px
linkStyle 6 stroke:#55f,stroke-width:2.0px
graph LR
1(("ce3dd4da<br/>NODE"))
2>"304b2acb<br/>ENCRYPTED"]
3(["a556ce89<br/>ASSERTION"])
4[/"7a4d6af9<br/>6"/]
5["5a568dcc<br/>SSKRShare"]
6(["c289fb91<br/>ASSERTION"])
7[/"e41178b8<br/>5"/]
8["7abac950<br/>SealedMessage"]
1 -->|subj| 2
1 --> 3
3 -->|pred| 4
3 -->|obj| 5
1 --> 6
6 -->|pred| 7
6 -->|obj| 8
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:#55f,stroke-width:3.0px
style 6 stroke:red,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke:green,stroke-width:2.0px
linkStyle 3 stroke:#55f,stroke-width:2.0px
linkStyle 4 stroke-width:2.0px
linkStyle 5 stroke:green,stroke-width:2.0px
linkStyle 6 stroke:#55f,stroke-width:2.0px
graph LR
1(("a9ceae00<br/>NODE"))
2>"304b2acb<br/>ENCRYPTED"]
3(["2e15cd04<br/>ASSERTION"])
4[/"e41178b8<br/>5"/]
5["5ebdc118<br/>SealedMessage"]
6(["47072fb8<br/>ASSERTION"])
7[/"7a4d6af9<br/>6"/]
8["2c01b8f1<br/>SSKRShare"]
1 -->|subj| 2
1 --> 3
3 -->|pred| 4
3 -->|obj| 5
1 --> 6
6 -->|pred| 7
6 -->|obj| 8
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:#55f,stroke-width:3.0px
style 6 stroke:red,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke:green,stroke-width:2.0px
linkStyle 3 stroke:#55f,stroke-width:2.0px
linkStyle 4 stroke-width:2.0px
linkStyle 5 stroke:green,stroke-width:2.0px
linkStyle 6 stroke:#55f,stroke-width:2.0px
Nadia’s ToneZone now has a data store that is independent, private, resilient, and open, fulfilling the Gordian Principles. But the ToneZone does more than that: it also allows Nadia to share her data in meaningful ways.
Part Two: Personal Shared Sensor Data
This second set of use cases describes how Nadia can leverage the data within her activity tracker in selective ways, to improve her personal wellness without giving away too much info.
4. Nadia Hearts Her Doctor (Elision)
- Use Case: Nadia wants to share a selection of her data with her doctor.
- Independence Benefits: Nadia can choose exactly what data to send.
- Privacy Benefits: Nadia can cut out data that she doesn’t want to share.
- Openness Benefits: The self-describing format means that the doctor’s app can easily unspool Nadia’s data.
Ideally, Nadia would like to share all of her data with her doctor, to maximize the efficacy of her care. Unfortunately, some of the data is very private. For example, her doctor just doesn’t need to know her geo data.
Moreso, in the currently oppressive environment in parts of the United States, some of her data could be personally dangerous if released, such as her temperature data, which could provide insights into her reproductive cycle and thus be weaponized by states that are restricting womens’ rights. Though she trusts her doctor, Nadia doesn’t trust the state not to subpoena data of that sort.
Fortunately, Gordian Envelope allows Nadia as the holder to elide her data as she sees fit. She starts with her unencrypted Envelope and cuts it down as appropriate (something that’s easy to do with the handy UI built into the ToneZone software).
The elided data Nadia hands her doctor looks like this:
ELIDED [
"account": {
"00000001" [
"birthdate": "19891109"
"fullName": "Nadia Levedeva"
"height": "65.1"
"weight": "132.7"
]
}
"device": {
"ToneZone 1.0" [
"heartInfoFor": "20230515" [
"1684274400": "59"
"1684274460": "60"
"1684274520": "60"
"1684274580": "59"
"1684274640": "59"
]
"heartInfoFor": "20230516" [
"1684274400": "85"
"1684274460": "87"
"1684274520": "91"
"1684274580": "90"
"1684274640": "88"
]
"statsFor": "20230515" [
"floors": "3"
"restingHeartRate": "55"
"steps": "5703"
"zoneMinutes": "0"
]
"statsFor": "20230516" [
"floors": "17"
"restingHeartRate": "56"
"steps": "10715"
"zoneMinutes": "25"
]
"stepInfoFor": "20230515" [
"1684188000": "0"
"1684188060": "0"
"1684188120": "7"
"1684188180": "2"
"1684188240": "0"
]
"stepInfoFor": "20230516" [
"1684274400": "95"
"1684274460": "99"
"1684274520": "103"
"1684274580": "103"
"1684274640": "101"
]
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
]
}
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
]
See the mermaid output.
Nadia’s doctor can see heart rates and how they relate to exercise, but she doesn’t have unneccessary or potentially dangerous data. Nadia’s goal of being able to share data in an independent, personal way is thus met.
5. Nadia is a Bit Remote (Multi-Permit)
- Use Case: Because of irregularities in her heart rate, Nadia wants to regularly share her data with a third-party health monitoring agency.
- Privacy Benefits: By creating multi-permits for her ToneZone data, Nadia can decide exactly what third-parties have access to her data.
- Openness Benefits: Like the doctor, the health monitoring agency can read the data because of its self-describing format.
Unfortunately, Nadia’s ToneZone data helps to alert her doctor to a potential heart condition, an arrhythmia, which is verified with additional testing.
ToneZone has formed partnerships with health monitoring services for situations exactly like this: they automatically monitor theira clients’ wellness data, to watch for dangerous events, such as afib or a heart attack. Nadia decides to take advantage of this service.
Nadia transfers data to the service using the same technique as casually mentioned in the SSKR example above: she generates a multipermit. This is a method by which she can encrypt the same data with multiple keys.
This is a two-step process. First, Nadia decides what data to encrypt for privacy, then she decides what data should also be locked with the account service’s public key. Though Nadia keeps her account info entirely private (with a single-key permit), she gives the monitoring service access to her device data (with a multipermit that can be unlocked with her encryption key or the service’s private key).
"ur:cid/hdcxzoqzispesnbbkohddwbyhtbzzsssdldassamdeeofdtndsaazsjpdtnnvwfnatglbgbnehwe" [
"account": ENCRYPTED
"device": ENCRYPTED [
hasRecipient: SealedMessage
]
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
]
graph LR
1(("60f74188<br/>NODE"))
2["426f3f8a<br/>#quot;ur:cid/hdcxzoqzispesnbbkohddwbyhtbzzsssd…#quot;"]
3(["38cadd4f<br/>ASSERTION"])
4["bb751b0e<br/>#quot;hasPubKey#quot;"]
5["2ada5820<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxtkzsswongh…#quot;"]
6(["ab36b175<br/>ASSERTION"])
7["52b252a6<br/>#quot;device#quot;"]
8(("6403b427<br/>NODE"))
9>"a6e75627<br/>ENCRYPTED"]
10(["2c8a6cc3<br/>ASSERTION"])
11[/"e41178b8<br/>5"/]
12["bcfd1406<br/>SealedMessage"]
13(["c75e3bff<br/>ASSERTION"])
14["a05e2863<br/>#quot;account#quot;"]
15>"f1bfd553<br/>ENCRYPTED"]
1 -->|subj| 2
1 --> 3
3 -->|pred| 4
3 -->|obj| 5
1 --> 6
6 -->|pred| 7
6 -->|obj| 8
8 -->|subj| 9
8 --> 10
10 -->|pred| 11
10 -->|obj| 12
1 --> 13
13 -->|pred| 14
13 -->|obj| 15
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:#55f,stroke-width:3.0px
style 6 stroke:red,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:red,stroke-width:3.0px
style 9 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 10 stroke:red,stroke-width:3.0px
style 11 stroke:#55f,stroke-width:3.0px
style 12 stroke:#55f,stroke-width:3.0px
style 13 stroke:red,stroke-width:3.0px
style 14 stroke:#55f,stroke-width:3.0px
style 15 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke:green,stroke-width:2.0px
linkStyle 3 stroke:#55f,stroke-width:2.0px
linkStyle 4 stroke-width:2.0px
linkStyle 5 stroke:green,stroke-width:2.0px
linkStyle 6 stroke:#55f,stroke-width:2.0px
linkStyle 7 stroke:red,stroke-width:2.0px
linkStyle 8 stroke-width:2.0px
linkStyle 9 stroke:green,stroke-width:2.0px
linkStyle 10 stroke:#55f,stroke-width:2.0px
linkStyle 11 stroke-width:2.0px
linkStyle 12 stroke:green,stroke-width:2.0px
linkStyle 13 stroke:#55f,stroke-width:2.0px
Now Nadia’s data can be safely transmitted to her monitoring service, but they can only access the exact data she allows. Meanwhile, Nadia also retains access to the data herself.
Note that this does change the hash, unlike simple encryption,
because a new assertion has been added (the hasRecipient sealed
message).
A similar technique could be used to allow parents to monitor their children or to help their elderly parents, with encrypted data being regularly streamed to an appropriate monitoring app.
6. Nadia Steps Up (Signature)
- Use Case: Nadia wants to submit validated step data to a stepping contest.
- Privacy Benefits: Multiple signatures assure everyone that the data is valid.
- Openness Benefits: This is another example of how self-describing data can open many doors.
Nadia is told to step up her steps for heart health, so she’s now working hard to get 10,000 steps a day. To encourage herself, she enters a step contest. Her ToneZone will submit elided daily counts of her steps, but the data must be validated since there are real prizes in the contest! Fortunately, ToneZone has its own private key. Data can be signed by it and submitted.
The data is heavily elided for this usage, something again automatically managed by the ToneZone UI:
ELIDED [
"device": {
"ToneZone 1.0" [
"statsFor": "20230515" [
"steps": "5703"
ELIDED (3)
]
"statsFor": "20230516" [
"steps": "10715"
ELIDED (3)
]
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
]
}
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
n ELIDED
]
The document must then be wrapped (so that the signature will apply to the entire Envelope) and signed.
The result looks like this:
{
ELIDED [
"device": {
"ToneZone 1.0" [
"statsFor": "20230515" [
"steps": "5703"
ELIDED (3)
]
"statsFor": "20230516" [
"steps": "10715"
ELIDED (3)
]
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
]
}
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
ELIDED
]
} [
verifiedBy: Signature [
note: "Signed by ToneZone Inc."
]
]
See the mermaid output.
The stepping contest can now verify the signature against ToneZone’s public key, and know that the data that Nadia submitted is valid. They could also ask Nadia to prove who she is by signing something using the private key associated with the public key referenced in the Envelope.
7. Nadia Foils Fusion (Salting)
- Use Case: Nadia needs to submit data to multiple parties and doesn’t want it correlated.
- Privacy Benefits: Nadia’s data is individually salted to prevent undesirable correlation.
Sensor Fusion is a general problem where data from multiple sensors can be combined in undesirable ways. Just the accelerometer in Nadia’s cell phone and the sensors in her activity tracker might be enough to create correlations that Nadia doesn’t want. Even if data isn’t personally identifiable, specific correlations might be enough to place someone into a certain category: overly high heart rate while at a geolocation revealed as a gym, for example, might place a data set into the undesirable category for a health insurance company. To properly protect private data, data streams need to be split in some way so that they’re not correlatable.
The issue can become even more problematic with elided data that retains its hashes, because multiple parties could combine data to give a more complete picture of the individual, each filling in data that was elided in the Envelope received by another person. Fortunately, there are a number of potential ways to deal with this issue.
Witness Nadia, who has continued to diversify her ToneZone data sharing. She wasn’t worried when she was mainly sharing data with doctors, who would be violating HIPAA if they shared her data incorrectly. But now she’s just sent information to a stepping contest and is about to send some data to her physical trainer. She’s becoming worried about how much of her overall information would be revealed if they and future recipients merged (“fused”) their data.
To avoid this problem, Nadia begins salting her data. This means that each batch of data that she sends out contains random numbers alongside her data. They might be totally random or they might be chained from some master salt, but either way they’re randomized and then applied to either individual assertions or data branches. By resalting her data each time it goes to a different part, Nadia reduces the opportunity for undesirable correlation because a recipient can’t look at an elided hash and realize that it matches a hash in someone else’s data record (whether it’s elided or not).
The following example shows Nadia’s sensor data with the major elements all salted in preparation for sending it to the step contest:
"ur:cid/hdcxzoqzispesnbbkohddwbyhtbzzsssdldassamdeeofdtndsaazsjpdtnnvwfnatglbgbnehwe" [
{
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
} [
salt: Salt
]
"account": {
"00000001" [
"birthdate": "19891109"
"fullName": "Nadia Levedeva"
"height": "65.1"
"weight": "132.7"
salt: Salt
]
}
"device": {
"ToneZone 1.0" [
{
"serialNumber": "SN102313A"
} [
salt: Salt
]
"gpsInfoFor": "20230516" [
"gpsQueue": "1684274400" [
"distance": "0"
"latitude": "2.122778"
"longitude": "41.380833"
"status": "0"
]
"gpsQueue": "1684279978" [
"distance": "5230"
"latitude": "2.456944"
"length": "36000"
"longitude": "41.430278"
"status": "8"
]
salt: Salt
]
"heartInfoFor": "20230515" [
"1684274400": "59"
"1684274460": "60"
"1684274520": "60"
"1684274580": "59"
"1684274640": "59"
salt: Salt
]
"heartInfoFor": "20230516" [
"1684274400": "85"
"1684274460": "87"
"1684274520": "91"
"1684274580": "90"
"1684274640": "88"
salt: Salt
]
"statsFor": "20230515" [
"floors": "3"
"restingHeartRate": "55"
"steps": "5703"
"zoneMinutes": "0"
salt: Salt
]
"statsFor": "20230516" [
"floors": "17"
"restingHeartRate": "56"
"steps": "10715"
"zoneMinutes": "25"
salt: Salt
]
"stepInfoFor": "20230515" [
"1684188000": "0"
"1684188060": "0"
"1684188120": "7"
"1684188180": "2"
"1684188240": "0"
salt: Salt
]
"stepInfoFor": "20230516" [
"1684274400": "95"
"1684274460": "99"
"1684274520": "103"
"1684274580": "103"
"1684274640": "101"
salt: Salt
]
"tempInfoFor": "20230515" [
"1684188000": "97"
"1684188060": "97.1"
"1684188120": "97.3"
"1684188180": "97.2"
"1684188240": "97.1"
salt: Salt
]
"tempInfoFor": "20230516" [
"1684274400": "98.2"
"1684274460": "98.2"
"1684274520": "98.3"
"1684274580": "98.2"
"1684274640": "98.2"
salt: Salt
]
salt: Salt
]
}
salt: Salt
]
As the mermaid diagram demonstrates, the hashes for those elements are all changed thanks to the inclusion of the Salt.
The elided data would then reveal only the info needed by the contest. Everything else is elided (as usual) and much of it was already salted so that the hashes can’t be correlated:
ELIDED [
{
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
} [
salt: Salt
]
"device": {
"ToneZone 1.0" [
{
ELIDED: ELIDED
} [
ELIDED
]
"statsFor": "20230515" [
"steps": "5703"
ELIDED (4)
]
"statsFor": "20230516" [
"steps": "10715"
ELIDED (4)
]
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
salt: ELIDED
]
}
ELIDED (2)
]
Every branch containing a salt has a different hash now. More importantly, they’ll have another different hash when Nadia regenerates her data for her physical trainer.
graph LR
1(("3d54fee3<br/>NODE"))
2426f3f8a<br/>ELIDED
38eebb7a8<br/>ELIDED
4(("d39c9f22<br/>NODE"))
5(["38cadd4f<br/>ASSERTION"])
6["bb751b0e<br/>#quot;hasPubKey#quot;"]
7["2ada5820<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxtkzsswongh…#quot;"]
8(["d52c7edb<br/>ASSERTION"])
9[/"aa14a6e0<br/>15"/]
10["0fd21960<br/>Salt"]
11e228433d<br/>ELIDED
12(["ea4a7af3<br/>ASSERTION"])
13["52b252a6<br/>#quot;device#quot;"]
14[/"d23558a8<br/>WRAPPED"\]
15(("9c6f9afc<br/>NODE"))
16["73a38bc2<br/>#quot;ToneZone 1.0#quot;"]
17(["0da1c06f<br/>ASSERTION"])
1811d623e4<br/>ELIDED
19e4d15c20<br/>ELIDED
20(["31275d4d<br/>ASSERTION"])
21f0b86b19<br/>ELIDED
22260f912d<br/>ELIDED
23(["31396aeb<br/>ASSERTION"])
2411d623e4<br/>ELIDED
251fa879b6<br/>ELIDED
26(["4ff93b04<br/>ASSERTION"])
27e6d5fe1d<br/>ELIDED
28a695ea27<br/>ELIDED
29(["55971106<br/>ASSERTION"])
30b9c6fb7b<br/>ELIDED
31abd77e35<br/>ELIDED
32(["9e2efdc5<br/>ASSERTION"])
33f0b86b19<br/>ELIDED
343aff4dd0<br/>ELIDED
35(["b17f12f6<br/>ASSERTION"])
36["92f9c9f7<br/>#quot;statsFor#quot;"]
37(("f8a7f7b8<br/>NODE"))
38["d1395bd4<br/>#quot;20230516#quot;"]
39(["098da37b<br/>ASSERTION"])
40["f16e83e2<br/>#quot;steps#quot;"]
41["1111a5a3<br/>#quot;10715#quot;"]
42307680cd<br/>ELIDED
433a57e931<br/>ELIDED
445929a395<br/>ELIDED
459c1f47ee<br/>ELIDED
46(("e5ad25dc<br/>NODE"))
47(["27bfa14c<br/>ASSERTION"])
484cbee23f<br/>ELIDED
49c2198002<br/>ELIDED
50cd58b980<br/>ELIDED
51(["e723e107<br/>ASSERTION"])
52b9c6fb7b<br/>ELIDED
53a043b8b2<br/>ELIDED
54(["eb9645b5<br/>ASSERTION"])
55[/"aa14a6e0<br/>15"/]
566fe0eca9<br/>ELIDED
57(["f44d64a6<br/>ASSERTION"])
58["92f9c9f7<br/>#quot;statsFor#quot;"]
59(("5a7effbf<br/>NODE"))
60["33241d8f<br/>#quot;20230515#quot;"]
61(["1cc98900<br/>ASSERTION"])
62["f16e83e2<br/>#quot;steps#quot;"]
63["42f3a37b<br/>#quot;5703#quot;"]
6435cd3369<br/>ELIDED
6540a7bef0<br/>ELIDED
6659826f73<br/>ELIDED
6761bfb33e<br/>ELIDED
1 -->|subj| 2
1 --> 3
1 --> 4
4 -->|subj| 5
5 -->|pred| 6
5 -->|obj| 7
4 --> 8
8 -->|pred| 9
8 -->|obj| 10
1 --> 11
1 --> 12
12 -->|pred| 13
12 -->|obj| 14
14 -->|subj| 15
15 -->|subj| 16
15 --> 17
17 -->|pred| 18
17 -->|obj| 19
15 --> 20
20 -->|pred| 21
20 -->|obj| 22
15 --> 23
23 -->|pred| 24
23 -->|obj| 25
15 --> 26
26 -->|pred| 27
26 -->|obj| 28
15 --> 29
29 -->|pred| 30
29 -->|obj| 31
15 --> 32
32 -->|pred| 33
32 -->|obj| 34
15 --> 35
35 -->|pred| 36
35 -->|obj| 37
37 -->|subj| 38
37 --> 39
39 -->|pred| 40
39 -->|obj| 41
37 --> 42
37 --> 43
37 --> 44
37 --> 45
15 --> 46
46 -->|subj| 47
47 -->|pred| 48
47 -->|obj| 49
46 --> 50
15 --> 51
51 -->|pred| 52
51 -->|obj| 53
15 --> 54
54 -->|pred| 55
54 -->|obj| 56
15 --> 57
57 -->|pred| 58
57 -->|obj| 59
59 -->|subj| 60
59 --> 61
61 -->|pred| 62
61 -->|obj| 63
59 --> 64
59 --> 65
59 --> 66
59 --> 67
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 3 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 4 stroke:red,stroke-width:3.0px
style 5 stroke:red,stroke-width:3.0px
style 6 stroke:#55f,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:red,stroke-width:3.0px
style 9 stroke:#55f,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px
style 11 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 12 stroke:red,stroke-width:3.0px
style 13 stroke:#55f,stroke-width:3.0px
style 14 stroke:red,stroke-width:3.0px
style 15 stroke:red,stroke-width:3.0px
style 16 stroke:#55f,stroke-width:3.0px
style 17 stroke:red,stroke-width:3.0px
style 18 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 19 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 20 stroke:red,stroke-width:3.0px
style 21 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 22 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 23 stroke:red,stroke-width:3.0px
style 24 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 25 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 26 stroke:red,stroke-width:3.0px
style 27 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 28 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 29 stroke:red,stroke-width:3.0px
style 30 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 31 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 32 stroke:red,stroke-width:3.0px
style 33 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 34 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 35 stroke:red,stroke-width:3.0px
style 36 stroke:#55f,stroke-width:3.0px
style 37 stroke:red,stroke-width:3.0px
style 38 stroke:#55f,stroke-width:3.0px
style 39 stroke:red,stroke-width:3.0px
style 40 stroke:#55f,stroke-width:3.0px
style 41 stroke:#55f,stroke-width:3.0px
style 42 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 43 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 44 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 45 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 46 stroke:red,stroke-width:3.0px
style 47 stroke:red,stroke-width:3.0px
style 48 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 49 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 50 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 51 stroke:red,stroke-width:3.0px
style 52 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 53 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 54 stroke:red,stroke-width:3.0px
style 55 stroke:#55f,stroke-width:3.0px
style 56 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 57 stroke:red,stroke-width:3.0px
style 58 stroke:#55f,stroke-width:3.0px
style 59 stroke:red,stroke-width:3.0px
style 60 stroke:#55f,stroke-width:3.0px
style 61 stroke:red,stroke-width:3.0px
style 62 stroke:#55f,stroke-width:3.0px
style 63 stroke:#55f,stroke-width:3.0px
style 64 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 65 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 66 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 67 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke-width:2.0px
linkStyle 3 stroke:red,stroke-width:2.0px
linkStyle 4 stroke:green,stroke-width:2.0px
linkStyle 5 stroke:#55f,stroke-width:2.0px
linkStyle 6 stroke-width:2.0px
linkStyle 7 stroke:green,stroke-width:2.0px
linkStyle 8 stroke:#55f,stroke-width:2.0px
linkStyle 9 stroke-width:2.0px
linkStyle 10 stroke-width:2.0px
linkStyle 11 stroke:green,stroke-width:2.0px
linkStyle 12 stroke:#55f,stroke-width:2.0px
linkStyle 13 stroke:red,stroke-width:2.0px
linkStyle 14 stroke:red,stroke-width:2.0px
linkStyle 15 stroke-width:2.0px
linkStyle 16 stroke:green,stroke-width:2.0px
linkStyle 17 stroke:#55f,stroke-width:2.0px
linkStyle 18 stroke-width:2.0px
linkStyle 19 stroke:green,stroke-width:2.0px
linkStyle 20 stroke:#55f,stroke-width:2.0px
linkStyle 21 stroke-width:2.0px
linkStyle 22 stroke:green,stroke-width:2.0px
linkStyle 23 stroke:#55f,stroke-width:2.0px
linkStyle 24 stroke-width:2.0px
linkStyle 25 stroke:green,stroke-width:2.0px
linkStyle 26 stroke:#55f,stroke-width:2.0px
linkStyle 27 stroke-width:2.0px
linkStyle 28 stroke:green,stroke-width:2.0px
linkStyle 29 stroke:#55f,stroke-width:2.0px
linkStyle 30 stroke-width:2.0px
linkStyle 31 stroke:green,stroke-width:2.0px
linkStyle 32 stroke:#55f,stroke-width:2.0px
linkStyle 33 stroke-width:2.0px
linkStyle 34 stroke:green,stroke-width:2.0px
linkStyle 35 stroke:#55f,stroke-width:2.0px
linkStyle 36 stroke:red,stroke-width:2.0px
linkStyle 37 stroke-width:2.0px
linkStyle 38 stroke:green,stroke-width:2.0px
linkStyle 39 stroke:#55f,stroke-width:2.0px
linkStyle 40 stroke-width:2.0px
linkStyle 41 stroke-width:2.0px
linkStyle 42 stroke-width:2.0px
linkStyle 43 stroke-width:2.0px
linkStyle 44 stroke-width:2.0px
linkStyle 45 stroke:red,stroke-width:2.0px
linkStyle 46 stroke:green,stroke-width:2.0px
linkStyle 47 stroke:#55f,stroke-width:2.0px
linkStyle 48 stroke-width:2.0px
linkStyle 49 stroke-width:2.0px
linkStyle 50 stroke:green,stroke-width:2.0px
linkStyle 51 stroke:#55f,stroke-width:2.0px
linkStyle 52 stroke-width:2.0px
linkStyle 53 stroke:green,stroke-width:2.0px
linkStyle 54 stroke:#55f,stroke-width:2.0px
linkStyle 55 stroke-width:2.0px
linkStyle 56 stroke:green,stroke-width:2.0px
linkStyle 57 stroke:#55f,stroke-width:2.0px
linkStyle 58 stroke:red,stroke-width:2.0px
linkStyle 59 stroke-width:2.0px
linkStyle 60 stroke:green,stroke-width:2.0px
linkStyle 61 stroke:#55f,stroke-width:2.0px
linkStyle 62 stroke-width:2.0px
linkStyle 63 stroke-width:2.0px
linkStyle 64 stroke-width:2.0px
linkStyle 65 stroke-width:2.0px
However, this individual incarnation of the Envelope, with its individual salt(s), will remain consistent, so that a signature can still be applied and it will remain valid.
{
ELIDED [
{
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
} [
salt: Salt
]
"device": {
"ToneZone 1.0" [
{
ELIDED: ELIDED
} [
ELIDED
]
"statsFor": "20230515" [
"steps": "5703"
ELIDED (4)
]
"statsFor": "20230516" [
"steps": "10715"
ELIDED (4)
]
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
salt: ELIDED
]
}
ELIDED (2)
]
} [
verifiedBy: Signature [
note: "Signed by ToneZone Inc."
]
]
graph LR
1(("f246d279<br/>NODE"))
2[/"85fb2b25<br/>WRAPPED"\]
3(("3d54fee3<br/>NODE"))
4426f3f8a<br/>ELIDED
58eebb7a8<br/>ELIDED
6(("d39c9f22<br/>NODE"))
7(["38cadd4f<br/>ASSERTION"])
8["bb751b0e<br/>#quot;hasPubKey#quot;"]
9["2ada5820<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxtkzsswongh…#quot;"]
10(["d52c7edb<br/>ASSERTION"])
11[/"aa14a6e0<br/>15"/]
12["0fd21960<br/>Salt"]
13e228433d<br/>ELIDED
14(["ea4a7af3<br/>ASSERTION"])
15["52b252a6<br/>#quot;device#quot;"]
16[/"d23558a8<br/>WRAPPED"\]
17(("9c6f9afc<br/>NODE"))
18["73a38bc2<br/>#quot;ToneZone 1.0#quot;"]
19(["0da1c06f<br/>ASSERTION"])
2011d623e4<br/>ELIDED
21e4d15c20<br/>ELIDED
22(["31275d4d<br/>ASSERTION"])
23f0b86b19<br/>ELIDED
24260f912d<br/>ELIDED
25(["31396aeb<br/>ASSERTION"])
2611d623e4<br/>ELIDED
271fa879b6<br/>ELIDED
28(["4ff93b04<br/>ASSERTION"])
29e6d5fe1d<br/>ELIDED
30a695ea27<br/>ELIDED
31(["55971106<br/>ASSERTION"])
32b9c6fb7b<br/>ELIDED
33abd77e35<br/>ELIDED
34(["9e2efdc5<br/>ASSERTION"])
35f0b86b19<br/>ELIDED
363aff4dd0<br/>ELIDED
37(["b17f12f6<br/>ASSERTION"])
38["92f9c9f7<br/>#quot;statsFor#quot;"]
39(("f8a7f7b8<br/>NODE"))
40["d1395bd4<br/>#quot;20230516#quot;"]
41(["098da37b<br/>ASSERTION"])
42["f16e83e2<br/>#quot;steps#quot;"]
43["1111a5a3<br/>#quot;10715#quot;"]
44307680cd<br/>ELIDED
453a57e931<br/>ELIDED
465929a395<br/>ELIDED
479c1f47ee<br/>ELIDED
48(("e5ad25dc<br/>NODE"))
49(["27bfa14c<br/>ASSERTION"])
504cbee23f<br/>ELIDED
51c2198002<br/>ELIDED
52cd58b980<br/>ELIDED
53(["e723e107<br/>ASSERTION"])
54b9c6fb7b<br/>ELIDED
55a043b8b2<br/>ELIDED
56(["eb9645b5<br/>ASSERTION"])
57[/"aa14a6e0<br/>15"/]
586fe0eca9<br/>ELIDED
59(["f44d64a6<br/>ASSERTION"])
60["92f9c9f7<br/>#quot;statsFor#quot;"]
61(("5a7effbf<br/>NODE"))
62["33241d8f<br/>#quot;20230515#quot;"]
63(["1cc98900<br/>ASSERTION"])
64["f16e83e2<br/>#quot;steps#quot;"]
65["42f3a37b<br/>#quot;5703#quot;"]
6635cd3369<br/>ELIDED
6740a7bef0<br/>ELIDED
6859826f73<br/>ELIDED
6961bfb33e<br/>ELIDED
70(["4eec285d<br/>ASSERTION"])
71[/"9d7ba9eb<br/>3"/]
72(("be1da528<br/>NODE"))
73["fe775bcb<br/>Signature"]
74(["1462e1a7<br/>ASSERTION"])
75[/"49a5f41b<br/>4"/]
76["5f9a1df7<br/>#quot;Signed by ToneZone Inc.#quot;"]
1 -->|subj| 2
2 -->|subj| 3
3 -->|subj| 4
3 --> 5
3 --> 6
6 -->|subj| 7
7 -->|pred| 8
7 -->|obj| 9
6 --> 10
10 -->|pred| 11
10 -->|obj| 12
3 --> 13
3 --> 14
14 -->|pred| 15
14 -->|obj| 16
16 -->|subj| 17
17 -->|subj| 18
17 --> 19
19 -->|pred| 20
19 -->|obj| 21
17 --> 22
22 -->|pred| 23
22 -->|obj| 24
17 --> 25
25 -->|pred| 26
25 -->|obj| 27
17 --> 28
28 -->|pred| 29
28 -->|obj| 30
17 --> 31
31 -->|pred| 32
31 -->|obj| 33
17 --> 34
34 -->|pred| 35
34 -->|obj| 36
17 --> 37
37 -->|pred| 38
37 -->|obj| 39
39 -->|subj| 40
39 --> 41
41 -->|pred| 42
41 -->|obj| 43
39 --> 44
39 --> 45
39 --> 46
39 --> 47
17 --> 48
48 -->|subj| 49
49 -->|pred| 50
49 -->|obj| 51
48 --> 52
17 --> 53
53 -->|pred| 54
53 -->|obj| 55
17 --> 56
56 -->|pred| 57
56 -->|obj| 58
17 --> 59
59 -->|pred| 60
59 -->|obj| 61
61 -->|subj| 62
61 --> 63
63 -->|pred| 64
63 -->|obj| 65
61 --> 66
61 --> 67
61 --> 68
61 --> 69
1 --> 70
70 -->|pred| 71
70 -->|obj| 72
72 -->|subj| 73
72 --> 74
74 -->|pred| 75
74 -->|obj| 76
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:red,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 5 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 6 stroke:red,stroke-width:3.0px
style 7 stroke:red,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px
style 9 stroke:#55f,stroke-width:3.0px
style 10 stroke:red,stroke-width:3.0px
style 11 stroke:#55f,stroke-width:3.0px
style 12 stroke:#55f,stroke-width:3.0px
style 13 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 14 stroke:red,stroke-width:3.0px
style 15 stroke:#55f,stroke-width:3.0px
style 16 stroke:red,stroke-width:3.0px
style 17 stroke:red,stroke-width:3.0px
style 18 stroke:#55f,stroke-width:3.0px
style 19 stroke:red,stroke-width:3.0px
style 20 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 21 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 22 stroke:red,stroke-width:3.0px
style 23 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 24 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 25 stroke:red,stroke-width:3.0px
style 26 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 27 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 28 stroke:red,stroke-width:3.0px
style 29 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 30 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 31 stroke:red,stroke-width:3.0px
style 32 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 33 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 34 stroke:red,stroke-width:3.0px
style 35 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 36 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 37 stroke:red,stroke-width:3.0px
style 38 stroke:#55f,stroke-width:3.0px
style 39 stroke:red,stroke-width:3.0px
style 40 stroke:#55f,stroke-width:3.0px
style 41 stroke:red,stroke-width:3.0px
style 42 stroke:#55f,stroke-width:3.0px
style 43 stroke:#55f,stroke-width:3.0px
style 44 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 45 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 46 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 47 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 48 stroke:red,stroke-width:3.0px
style 49 stroke:red,stroke-width:3.0px
style 50 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 51 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 52 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 53 stroke:red,stroke-width:3.0px
style 54 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 55 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 56 stroke:red,stroke-width:3.0px
style 57 stroke:#55f,stroke-width:3.0px
style 58 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 59 stroke:red,stroke-width:3.0px
style 60 stroke:#55f,stroke-width:3.0px
style 61 stroke:red,stroke-width:3.0px
style 62 stroke:#55f,stroke-width:3.0px
style 63 stroke:red,stroke-width:3.0px
style 64 stroke:#55f,stroke-width:3.0px
style 65 stroke:#55f,stroke-width:3.0px
style 66 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 67 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 68 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 69 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 70 stroke:red,stroke-width:3.0px
style 71 stroke:#55f,stroke-width:3.0px
style 72 stroke:red,stroke-width:3.0px
style 73 stroke:#55f,stroke-width:3.0px
style 74 stroke:red,stroke-width:3.0px
style 75 stroke:#55f,stroke-width:3.0px
style 76 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke:red,stroke-width:2.0px
linkStyle 2 stroke:red,stroke-width:2.0px
linkStyle 3 stroke-width:2.0px
linkStyle 4 stroke-width:2.0px
linkStyle 5 stroke:red,stroke-width:2.0px
linkStyle 6 stroke:green,stroke-width:2.0px
linkStyle 7 stroke:#55f,stroke-width:2.0px
linkStyle 8 stroke-width:2.0px
linkStyle 9 stroke:green,stroke-width:2.0px
linkStyle 10 stroke:#55f,stroke-width:2.0px
linkStyle 11 stroke-width:2.0px
linkStyle 12 stroke-width:2.0px
linkStyle 13 stroke:green,stroke-width:2.0px
linkStyle 14 stroke:#55f,stroke-width:2.0px
linkStyle 15 stroke:red,stroke-width:2.0px
linkStyle 16 stroke:red,stroke-width:2.0px
linkStyle 17 stroke-width:2.0px
linkStyle 18 stroke:green,stroke-width:2.0px
linkStyle 19 stroke:#55f,stroke-width:2.0px
linkStyle 20 stroke-width:2.0px
linkStyle 21 stroke:green,stroke-width:2.0px
linkStyle 22 stroke:#55f,stroke-width:2.0px
linkStyle 23 stroke-width:2.0px
linkStyle 24 stroke:green,stroke-width:2.0px
linkStyle 25 stroke:#55f,stroke-width:2.0px
linkStyle 26 stroke-width:2.0px
linkStyle 27 stroke:green,stroke-width:2.0px
linkStyle 28 stroke:#55f,stroke-width:2.0px
linkStyle 29 stroke-width:2.0px
linkStyle 30 stroke:green,stroke-width:2.0px
linkStyle 31 stroke:#55f,stroke-width:2.0px
linkStyle 32 stroke-width:2.0px
linkStyle 33 stroke:green,stroke-width:2.0px
linkStyle 34 stroke:#55f,stroke-width:2.0px
linkStyle 35 stroke-width:2.0px
linkStyle 36 stroke:green,stroke-width:2.0px
linkStyle 37 stroke:#55f,stroke-width:2.0px
linkStyle 38 stroke:red,stroke-width:2.0px
linkStyle 39 stroke-width:2.0px
linkStyle 40 stroke:green,stroke-width:2.0px
linkStyle 41 stroke:#55f,stroke-width:2.0px
linkStyle 42 stroke-width:2.0px
linkStyle 43 stroke-width:2.0px
linkStyle 44 stroke-width:2.0px
linkStyle 45 stroke-width:2.0px
linkStyle 46 stroke-width:2.0px
linkStyle 47 stroke:red,stroke-width:2.0px
linkStyle 48 stroke:green,stroke-width:2.0px
linkStyle 49 stroke:#55f,stroke-width:2.0px
linkStyle 50 stroke-width:2.0px
linkStyle 51 stroke-width:2.0px
linkStyle 52 stroke:green,stroke-width:2.0px
linkStyle 53 stroke:#55f,stroke-width:2.0px
linkStyle 54 stroke-width:2.0px
linkStyle 55 stroke:green,stroke-width:2.0px
linkStyle 56 stroke:#55f,stroke-width:2.0px
linkStyle 57 stroke-width:2.0px
linkStyle 58 stroke:green,stroke-width:2.0px
linkStyle 59 stroke:#55f,stroke-width:2.0px
linkStyle 60 stroke:red,stroke-width:2.0px
linkStyle 61 stroke-width:2.0px
linkStyle 62 stroke:green,stroke-width:2.0px
linkStyle 63 stroke:#55f,stroke-width:2.0px
linkStyle 64 stroke-width:2.0px
linkStyle 65 stroke-width:2.0px
linkStyle 66 stroke-width:2.0px
linkStyle 67 stroke-width:2.0px
linkStyle 68 stroke-width:2.0px
linkStyle 69 stroke:green,stroke-width:2.0px
linkStyle 70 stroke:#55f,stroke-width:2.0px
linkStyle 71 stroke:red,stroke-width:2.0px
linkStyle 72 stroke-width:2.0px
linkStyle 73 stroke:green,stroke-width:2.0px
linkStyle 74 stroke:#55f,stroke-width:2.0px
There are other methods to help blur the types of behavioral fingerprint. Improving methodologies to avoid sensor fusion is likely to be a big topic for the future. But, it needs to be balanced with the fact that some correlation is desirable: one of the purposes of hashed elision is to allow continued authentication, but another is to allow proof that hidden data was part of a data package (as Nadia will do after she submits data to a clinical trial). Ultimately, that means that designers and users both must decide when to try and foil correlation and when to embrace it.
Part Three: Clinically Shared Sensor Data
This third set of use cases describes how Nadia can also support clinical trials, which are important public health initiatives. In these situations, even more care might be taken to ensure data privacy, but that has to be done simultaneously with provenance that maintains the validity of the trials.
8. Nadia Gets Clinical (Elision, Third-Party Encryption)
- Use Case: Nadia wants to submit data to a clinical trial.
- Privacy Benefits: Nadia’s data is protected so that she can’t be identified. ToneZone is protected from accidentally acquiring any “toxic” data as well.
- Openness Benefits: Clinical trials are one of the most important communities that can benefit from open data.
Personal health is important, but so is public health, and wearable activity trackers make it easy to support that type of research. Nadia believes strongly is this type of public good, so she’s decided to take part in a clinical trial.
Nadia can apply for trials directly using the ToneZone app. When she does so, she agrees exactly what data will be shared and also receives a public key to encrypt the data.
This results in the creation of elided data, such as this one, for a clinical trial relating steps to heart rate:
ELIDED [
"device": {
"ToneZone 1.0" [
"heartInfoFor": "20230515" [
"1684274400": "59"
"1684274460": "60"
"1684274520": "60"
"1684274580": "59"
"1684274640": "59"
]
"heartInfoFor": "20230516" [
"1684274400": "85"
"1684274460": "87"
"1684274520": "91"
"1684274580": "90"
"1684274640": "88"
]
"statsFor": "20230515" [
"restingHeartRate": "55"
"steps": "5703"
ELIDED (2)
]
"statsFor": "20230516" [
"restingHeartRate": "56"
"steps": "10715"
ELIDED (2)
]
"stepInfoFor": "20230515" [
"1684188000": "0"
"1684188060": "0"
"1684188120": "7"
"1684188180": "2"
"1684188240": "0"
]
"stepInfoFor": "20230516" [
"1684274400": "95"
"1684274460": "99"
"1684274520": "103"
"1684274580": "103"
"1684274640": "101"
]
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
]
}
"hasPubKey": ELIDED
ELIDED
]
See the mermaid output.
The clinical trial will require proof of provenance. This is managed with a ToneZone signature, validating the date, just as with the step contest that Nadia participated in.
{
ELIDED [
"device": {
"ToneZone 1.0" [
"heartInfoFor": "20230515" [
"1684274400": "59"
"1684274460": "60"
"1684274520": "60"
"1684274580": "59"
"1684274640": "59"
]
"heartInfoFor": "20230516" [
"1684274400": "85"
"1684274460": "87"
"1684274520": "91"
"1684274580": "90"
"1684274640": "88"
]
"statsFor": "20230515" [
"restingHeartRate": "55"
"steps": "5703"
ELIDED (2)
]
"statsFor": "20230516" [
"restingHeartRate": "56"
"steps": "10715"
ELIDED (2)
]
"stepInfoFor": "20230515" [
"1684188000": "0"
"1684188060": "0"
"1684188120": "7"
"1684188180": "2"
"1684188240": "0"
]
"stepInfoFor": "20230516" [
"1684274400": "95"
"1684274460": "99"
"1684274520": "103"
"1684274580": "103"
"1684274640": "101"
]
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
ELIDED: ELIDED
]
}
"hasPubKey": ELIDED
ELIDED
]
} [
verifiedBy: Signature [
note: "Signed by ToneZone Inc."
]
]
See the mermaid output.
Finally, Nadia wraps the data and encrypts it with the clinical trial’s public key:
ENCRYPTED [
hasRecipient: SealedMessage
]
graph LR
1(("1b5666c8<br/>NODE"))
2>"acab46a2<br/>ENCRYPTED"]
3(["a0ad65d5<br/>ASSERTION"])
4[/"e41178b8<br/>5"/]
5["5e6cc846<br/>SealedMessage"]
1 -->|subj| 2
1 --> 3
3 -->|pred| 4
3 -->|obj| 5
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke:green,stroke-width:2.0px
linkStyle 3 stroke:#55f,stroke-width:2.0px
This last step is crucial, not just because the data should be encrypted (though it’s largely been anonymized through elision). It’s also important because ToneZone is out of necessity the carrier of the information: going through the ToneZone app is the only way to automatically and easily ensure this data is regularly updated, which is the whole point, since it makes the clinical trials more likely to succeed thanks to robust and regular data collection.
But, Nadia doesn’t want her data to go to ToneZone, and ToneZone doesn’t want data that could be potentially toxic, depending on how personal and identifiable the data being collected is. Fortunately, the use of third-party encryption through the clinical trial’s own key provides a perfect solution.
Overall:
- Administration has been dramatically simplified through automation.
- HIPAA requirements for the clinical study have been dramatically simplified through careful elision of data.
- ToneZone has been entirely exempted from HIPAA concerns thanks to third-party encryption.
- Costs have been overall reduced.
As a result, clinical trials can be much more successful at dealing with the health questions at their core!
A more complex situation might have data being regularly uploaded to ToneZone, some of which ToneZone keeps, to help Nadia with her wellness, and some of which is passed on to the clinical trial. In this case, multipermits are again used, designating which data goes to which people via different encryption keys.
9. Nadia Proves her Worth (Proof of Inclusion)
- Use Case: Nadia wants to prove that she participated in a clinical study.
- Privacy Benefits: Nadia only reveals that her data is part of the clinical trial when she chooses to do so.
Nadia learns that her health insurance company encourages participation in clinical trials with a 2% discount on her insurance rate. She has to think about whether she’s willing to give her insurance company this info, but ultimately decides that the dangers are relatively low for them being able to discriminate against her as a result, thanks to the ACA. She just needs to prove that she participated.
This is done with a proof of inclusion.
Obviously, the clinic trial needs to make a publication to support this, but it’s something that they want to do anyway, to offer support for the validity of their trial.
One possibility is for them to release further elided versions of the unencrypted, signed data packets that they receive. That’s one of the advantages of Gordian Envelope: each holder can further elide or repackage data as they see fit.
The following shows a further elided envelope that only contains the
validation info for the data: the ToneZone signature and the
hasPubKey statement (though the clinical trial doesn’t actually know
what the public key is because Nadia elided it before submission!)
{
ELIDED [
"hasPubKey": ELIDED
ELIDED: ELIDED
ELIDED
]
} [
verifiedBy: Signature [
note: "Signed by ToneZone Inc."
]
]
graph LR
1(("0410cc94<br/>NODE"))
2[/"80134e1e<br/>WRAPPED"\]
3(("4f3ced9e<br/>NODE"))
4426f3f8a<br/>ELIDED
5(["38cadd4f<br/>ASSERTION"])
6["bb751b0e<br/>#quot;hasPubKey#quot;"]
72ada5820<br/>ELIDED
8c75e3bff<br/>ELIDED
9(["cac8aa12<br/>ASSERTION"])
1052b252a6<br/>ELIDED
11a6e75627<br/>ELIDED
12(["2bcddfb6<br/>ASSERTION"])
13[/"9d7ba9eb<br/>3"/]
14(("0a7ab794<br/>NODE"))
15["1073a477<br/>Signature"]
16(["1462e1a7<br/>ASSERTION"])
17[/"49a5f41b<br/>4"/]
18["5f9a1df7<br/>#quot;Signed by ToneZone Inc.#quot;"]
1 -->|subj| 2
2 -->|subj| 3
3 -->|subj| 4
3 --> 5
5 -->|pred| 6
5 -->|obj| 7
3 --> 8
3 --> 9
9 -->|pred| 10
9 -->|obj| 11
1 --> 12
12 -->|pred| 13
12 -->|obj| 14
14 -->|subj| 15
14 --> 16
16 -->|pred| 17
16 -->|obj| 18
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:red,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 5 stroke:red,stroke-width:3.0px
style 6 stroke:#55f,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 8 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 9 stroke:red,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 11 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 12 stroke:red,stroke-width:3.0px
style 13 stroke:#55f,stroke-width:3.0px
style 14 stroke:red,stroke-width:3.0px
style 15 stroke:#55f,stroke-width:3.0px
style 16 stroke:red,stroke-width:3.0px
style 17 stroke:#55f,stroke-width:3.0px
style 18 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke:red,stroke-width:2.0px
linkStyle 2 stroke:red,stroke-width:2.0px
linkStyle 3 stroke-width:2.0px
linkStyle 4 stroke:green,stroke-width:2.0px
linkStyle 5 stroke:#55f,stroke-width:2.0px
linkStyle 6 stroke-width:2.0px
linkStyle 7 stroke-width:2.0px
linkStyle 8 stroke:green,stroke-width:2.0px
linkStyle 9 stroke:#55f,stroke-width:2.0px
linkStyle 10 stroke-width:2.0px
linkStyle 11 stroke:green,stroke-width:2.0px
linkStyle 12 stroke:#55f,stroke-width:2.0px
linkStyle 13 stroke:red,stroke-width:2.0px
linkStyle 14 stroke-width:2.0px
linkStyle 15 stroke:green,stroke-width:2.0px
linkStyle 16 stroke:#55f,stroke-width:2.0px
The other option would be for the clinical trial to create a totally new Gordian Envelope, which contains only the (elided) public key data. This would have the benefit of there being just a single publication.
In either case, the clinical trial publishes data that contains
Nadia’s public key in elided form. Nadia can now prove her
participation. She does this by having her ToneZone extract her
hasPubKey info from her data:
ur:envelope/tpsolftpsptpcsinishsjkgdkpidgrihkktpsptpcskspfkpjpftiajpkkjojyjldpjokpidjeihkkjkdljziyjyhshsieiyktisieiaksjyjeknjkjkktjljtioisjoieihjnjojyiajojzkpiejejejyinhsjzjtjtkkknjnhsiejyjziejzidjkjyhsidktktjnihiakojyiyioisjeiajeiyknjyjzieihjnktjyhshsieiejnisieiaksjpkkjojyjkihihjkiejpimjojkjkidknktjnjlksktjekojzihkkjpjtidiojtjkknjlhsjyhsjyjskniojzjohsihjyieihjziyjtidjokkiojzhsjljyjzjejyiakkiyjzjzkpidknihiskgsnfyao
"hasPubKey": "ur:crypto-pubkeys/lftaadfwhdcxtkzsswonghpdemptcpludkktialnnyzmadtldlbstabwwmecvtfghkckfztldemwtaaddmhdcxryptseesdrjpssbzwmoxwkvleyrnbgnszoatatqzglpaetdelfnbpyglaotlktcyfllubzeh"
graph LR
1(["38cadd4f<br/>ASSERTION"])
2["bb751b0e<br/>#quot;hasPubKey#quot;"]
3["2ada5820<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxtkzsswongh…#quot;"]
1 -->|pred| 2
1 -->|obj| 3
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px
style 3 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:green,stroke-width:2.0px
linkStyle 1 stroke:#55f,stroke-width:2.0px
if she reveals this, anyone can then compared the hash of the
assertion (38cadd4f) with the ELIDED assertion in the published
(but elided) clinical trial assertion. They match up!
Since collisions are nearly impossible in strong hashes such as the one used with Gordian Envelope, that’s sufficient proof that Nadia was a participant — though it would have been impossible for anyone to figure out without Nadia’s revelation, as hashes are also one-way functions.
10. Nadia Becomes a Number (Anonymization, Provenance)
- Use Case: Clinical trials sometimes need to further de-identify data but want to maintain its provenance.
- Privacy Benefits: Nadia’s data becomes even more anonymous.
There is a submarket for further de-identifying clinical data. Some of this must be done by hand, which overall results in higher costs and lower efficiencies in trials.
Gordian Envelope allows Nadia’s data to be further de-identified while still maintaining its provenance. This is done by maintaining the original data in deep data silos, but fully eliding data used in the trial: only the master hash and the signature data are maintained, the first to allow for lookup of the original data if its existence ever needs to be proven, the second to maintain easy lookup of the data’s validation, in case any validator is ever proven to be untrustworthy.
The clinical trial then wraps that provenance information and creates a new set of data with five-minute averages from the previous data, making it less identifiable. (Even more extreme data blurring techniques could be used, if required, provided that the same methodology for linking the new data with the provenance for its origin is used.)
{
ELIDED [
verifiedBy: Signature [
note: "Signed by ToneZone Inc."
]
]
} [
"heartInfoBlur": "20230515" [
"1684188000": "59.4"
"1684188300": "59.6"
]
"heartInfoBlur": "20230516" [
"1684274400": "88.2"
"1684274700": "87.4"
]
"stepInfoBlur": "20230515" [
"1684188000": "9"
"1684188300": "67"
]
"stepInfoBlur": "20230516" [
"1684188300": "470"
"1684274400": "502"
]
]
graph LR
1(("4dbe61aa<br/>NODE"))
2[/"acab46a2<br/>WRAPPED"\]
3(("0410cc94<br/>NODE"))
480134e1e<br/>ELIDED
5(["2bcddfb6<br/>ASSERTION"])
6[/"9d7ba9eb<br/>3"/]
7(("0a7ab794<br/>NODE"))
8["1073a477<br/>Signature"]
9(["1462e1a7<br/>ASSERTION"])
10[/"49a5f41b<br/>4"/]
11["5f9a1df7<br/>#quot;Signed by ToneZone Inc.#quot;"]
12(["2a2e6d3c<br/>ASSERTION"])
13["57e0b082<br/>#quot;heartInfoBlur#quot;"]
14(("989eafca<br/>NODE"))
15["d1395bd4<br/>#quot;20230516#quot;"]
16(["a76528b0<br/>ASSERTION"])
17["cf7b4592<br/>#quot;1684274700#quot;"]
18["c0f588df<br/>#quot;87.4#quot;"]
19(["e39d6d7e<br/>ASSERTION"])
20["2f1526b7<br/>#quot;1684274400#quot;"]
21["43107349<br/>#quot;88.2#quot;"]
22(["6c1c9479<br/>ASSERTION"])
23["44b6e7a7<br/>#quot;stepInfoBlur#quot;"]
24(("a737c4df<br/>NODE"))
25["d1395bd4<br/>#quot;20230516#quot;"]
26(["2df0a5cc<br/>ASSERTION"])
27["2f1526b7<br/>#quot;1684274400#quot;"]
28["7c885771<br/>#quot;502#quot;"]
29(["604028fc<br/>ASSERTION"])
30["6a85544b<br/>#quot;1684188300#quot;"]
31["4ad8ba7a<br/>#quot;470#quot;"]
32(["d34d3e9e<br/>ASSERTION"])
33["44b6e7a7<br/>#quot;stepInfoBlur#quot;"]
34(("f3be2a5c<br/>NODE"))
35["33241d8f<br/>#quot;20230515#quot;"]
36(["e7984694<br/>ASSERTION"])
37["2946850e<br/>#quot;1684188000#quot;"]
38["2b12242f<br/>#quot;9#quot;"]
39(["f741f132<br/>ASSERTION"])
40["6a85544b<br/>#quot;1684188300#quot;"]
41["626e242b<br/>#quot;67#quot;"]
42(["fc3075d7<br/>ASSERTION"])
43["57e0b082<br/>#quot;heartInfoBlur#quot;"]
44(("f869cea1<br/>NODE"))
45["33241d8f<br/>#quot;20230515#quot;"]
46(["5102c67e<br/>ASSERTION"])
47["6a85544b<br/>#quot;1684188300#quot;"]
48["0b1d9a73<br/>#quot;59.6#quot;"]
49(["9de9f69a<br/>ASSERTION"])
50["2946850e<br/>#quot;1684188000#quot;"]
51["e975becd<br/>#quot;59.4#quot;"]
1 -->|subj| 2
2 -->|subj| 3
3 -->|subj| 4
3 --> 5
5 -->|pred| 6
5 -->|obj| 7
7 -->|subj| 8
7 --> 9
9 -->|pred| 10
9 -->|obj| 11
1 --> 12
12 -->|pred| 13
12 -->|obj| 14
14 -->|subj| 15
14 --> 16
16 -->|pred| 17
16 -->|obj| 18
14 --> 19
19 -->|pred| 20
19 -->|obj| 21
1 --> 22
22 -->|pred| 23
22 -->|obj| 24
24 -->|subj| 25
24 --> 26
26 -->|pred| 27
26 -->|obj| 28
24 --> 29
29 -->|pred| 30
29 -->|obj| 31
1 --> 32
32 -->|pred| 33
32 -->|obj| 34
34 -->|subj| 35
34 --> 36
36 -->|pred| 37
36 -->|obj| 38
34 --> 39
39 -->|pred| 40
39 -->|obj| 41
1 --> 42
42 -->|pred| 43
42 -->|obj| 44
44 -->|subj| 45
44 --> 46
46 -->|pred| 47
46 -->|obj| 48
44 --> 49
49 -->|pred| 50
49 -->|obj| 51
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:red,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 5 stroke:red,stroke-width:3.0px
style 6 stroke:#55f,stroke-width:3.0px
style 7 stroke:red,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px
style 9 stroke:red,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px
style 11 stroke:#55f,stroke-width:3.0px
style 12 stroke:red,stroke-width:3.0px
style 13 stroke:#55f,stroke-width:3.0px
style 14 stroke:red,stroke-width:3.0px
style 15 stroke:#55f,stroke-width:3.0px
style 16 stroke:red,stroke-width:3.0px
style 17 stroke:#55f,stroke-width:3.0px
style 18 stroke:#55f,stroke-width:3.0px
style 19 stroke:red,stroke-width:3.0px
style 20 stroke:#55f,stroke-width:3.0px
style 21 stroke:#55f,stroke-width:3.0px
style 22 stroke:red,stroke-width:3.0px
style 23 stroke:#55f,stroke-width:3.0px
style 24 stroke:red,stroke-width:3.0px
style 25 stroke:#55f,stroke-width:3.0px
style 26 stroke:red,stroke-width:3.0px
style 27 stroke:#55f,stroke-width:3.0px
style 28 stroke:#55f,stroke-width:3.0px
style 29 stroke:red,stroke-width:3.0px
style 30 stroke:#55f,stroke-width:3.0px
style 31 stroke:#55f,stroke-width:3.0px
style 32 stroke:red,stroke-width:3.0px
style 33 stroke:#55f,stroke-width:3.0px
style 34 stroke:red,stroke-width:3.0px
style 35 stroke:#55f,stroke-width:3.0px
style 36 stroke:red,stroke-width:3.0px
style 37 stroke:#55f,stroke-width:3.0px
style 38 stroke:#55f,stroke-width:3.0px
style 39 stroke:red,stroke-width:3.0px
style 40 stroke:#55f,stroke-width:3.0px
style 41 stroke:#55f,stroke-width:3.0px
style 42 stroke:red,stroke-width:3.0px
style 43 stroke:#55f,stroke-width:3.0px
style 44 stroke:red,stroke-width:3.0px
style 45 stroke:#55f,stroke-width:3.0px
style 46 stroke:red,stroke-width:3.0px
style 47 stroke:#55f,stroke-width:3.0px
style 48 stroke:#55f,stroke-width:3.0px
style 49 stroke:red,stroke-width:3.0px
style 50 stroke:#55f,stroke-width:3.0px
style 51 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke:red,stroke-width:2.0px
linkStyle 2 stroke:red,stroke-width:2.0px
linkStyle 3 stroke-width:2.0px
linkStyle 4 stroke:green,stroke-width:2.0px
linkStyle 5 stroke:#55f,stroke-width:2.0px
linkStyle 6 stroke:red,stroke-width:2.0px
linkStyle 7 stroke-width:2.0px
linkStyle 8 stroke:green,stroke-width:2.0px
linkStyle 9 stroke:#55f,stroke-width:2.0px
linkStyle 10 stroke-width:2.0px
linkStyle 11 stroke:green,stroke-width:2.0px
linkStyle 12 stroke:#55f,stroke-width:2.0px
linkStyle 13 stroke:red,stroke-width:2.0px
linkStyle 14 stroke-width:2.0px
linkStyle 15 stroke:green,stroke-width:2.0px
linkStyle 16 stroke:#55f,stroke-width:2.0px
linkStyle 17 stroke-width:2.0px
linkStyle 18 stroke:green,stroke-width:2.0px
linkStyle 19 stroke:#55f,stroke-width:2.0px
linkStyle 20 stroke-width:2.0px
linkStyle 21 stroke:green,stroke-width:2.0px
linkStyle 22 stroke:#55f,stroke-width:2.0px
linkStyle 23 stroke:red,stroke-width:2.0px
linkStyle 24 stroke-width:2.0px
linkStyle 25 stroke:green,stroke-width:2.0px
linkStyle 26 stroke:#55f,stroke-width:2.0px
linkStyle 27 stroke-width:2.0px
linkStyle 28 stroke:green,stroke-width:2.0px
linkStyle 29 stroke:#55f,stroke-width:2.0px
linkStyle 30 stroke-width:2.0px
linkStyle 31 stroke:green,stroke-width:2.0px
linkStyle 32 stroke:#55f,stroke-width:2.0px
linkStyle 33 stroke:red,stroke-width:2.0px
linkStyle 34 stroke-width:2.0px
linkStyle 35 stroke:green,stroke-width:2.0px
linkStyle 36 stroke:#55f,stroke-width:2.0px
linkStyle 37 stroke-width:2.0px
linkStyle 38 stroke:green,stroke-width:2.0px
linkStyle 39 stroke:#55f,stroke-width:2.0px
linkStyle 40 stroke-width:2.0px
linkStyle 41 stroke:green,stroke-width:2.0px
linkStyle 42 stroke:#55f,stroke-width:2.0px
linkStyle 43 stroke:red,stroke-width:2.0px
linkStyle 44 stroke-width:2.0px
linkStyle 45 stroke:green,stroke-width:2.0px
linkStyle 46 stroke:#55f,stroke-width:2.0px
linkStyle 47 stroke-width:2.0px
linkStyle 48 stroke:green,stroke-width:2.0px
linkStyle 49 stroke:#55f,stroke-width:2.0px
Note that even in the heavily elided root data, the root hash
(0410cc94) continues to be visible. That’s what connects this elided
data to the original if the clinical trial’s data ever needs to be
validated.
To further validate everything, the Clinical Trial would of course sign this blurred data as well, verifying the standards by which the blurring had occurred:
{
{
ELIDED [
verifiedBy: Signature [
note: "Signed by ToneZone Inc."
]
]
} [
"heartInfoBlur": "20230515" [
"1684188000": "59.4"
"1684188300": "59.6"
]
"heartInfoBlur": "20230516" [
"1684274400": "88.2"
"1684274700": "87.4"
]
"stepInfoBlur": "20230515" [
"1684188000": "9"
"1684188300": "67"
]
"stepInfoBlur": "20230516" [
"1684188300": "470"
"1684274400": "502"
]
]
} [
verifiedBy: Signature [
note: "Signed by Clinical Trial Inc."
]
]
graph LR
1(("2d9e18b8<br/>NODE"))
2[/"76825215<br/>WRAPPED"\]
3(("4dbe61aa<br/>NODE"))
4[/"acab46a2<br/>WRAPPED"\]
5(("0410cc94<br/>NODE"))
680134e1e<br/>ELIDED
7(["2bcddfb6<br/>ASSERTION"])
8[/"9d7ba9eb<br/>3"/]
9(("0a7ab794<br/>NODE"))
10["1073a477<br/>Signature"]
11(["1462e1a7<br/>ASSERTION"])
12[/"49a5f41b<br/>4"/]
13["5f9a1df7<br/>#quot;Signed by ToneZone Inc.#quot;"]
14(["2a2e6d3c<br/>ASSERTION"])
15["57e0b082<br/>#quot;heartInfoBlur#quot;"]
16(("989eafca<br/>NODE"))
17["d1395bd4<br/>#quot;20230516#quot;"]
18(["a76528b0<br/>ASSERTION"])
19["cf7b4592<br/>#quot;1684274700#quot;"]
20["c0f588df<br/>#quot;87.4#quot;"]
21(["e39d6d7e<br/>ASSERTION"])
22["2f1526b7<br/>#quot;1684274400#quot;"]
23["43107349<br/>#quot;88.2#quot;"]
24(["6c1c9479<br/>ASSERTION"])
25["44b6e7a7<br/>#quot;stepInfoBlur#quot;"]
26(("a737c4df<br/>NODE"))
27["d1395bd4<br/>#quot;20230516#quot;"]
28(["2df0a5cc<br/>ASSERTION"])
29["2f1526b7<br/>#quot;1684274400#quot;"]
30["7c885771<br/>#quot;502#quot;"]
31(["604028fc<br/>ASSERTION"])
32["6a85544b<br/>#quot;1684188300#quot;"]
33["4ad8ba7a<br/>#quot;470#quot;"]
34(["d34d3e9e<br/>ASSERTION"])
35["44b6e7a7<br/>#quot;stepInfoBlur#quot;"]
36(("f3be2a5c<br/>NODE"))
37["33241d8f<br/>#quot;20230515#quot;"]
38(["e7984694<br/>ASSERTION"])
39["2946850e<br/>#quot;1684188000#quot;"]
40["2b12242f<br/>#quot;9#quot;"]
41(["f741f132<br/>ASSERTION"])
42["6a85544b<br/>#quot;1684188300#quot;"]
43["626e242b<br/>#quot;67#quot;"]
44(["fc3075d7<br/>ASSERTION"])
45["57e0b082<br/>#quot;heartInfoBlur#quot;"]
46(("f869cea1<br/>NODE"))
47["33241d8f<br/>#quot;20230515#quot;"]
48(["5102c67e<br/>ASSERTION"])
49["6a85544b<br/>#quot;1684188300#quot;"]
50["0b1d9a73<br/>#quot;59.6#quot;"]
51(["9de9f69a<br/>ASSERTION"])
52["2946850e<br/>#quot;1684188000#quot;"]
53["e975becd<br/>#quot;59.4#quot;"]
54(["f77b895c<br/>ASSERTION"])
55[/"9d7ba9eb<br/>3"/]
56(("19f337dc<br/>NODE"))
57["713b9bb9<br/>Signature"]
58(["7d615ea2<br/>ASSERTION"])
59[/"49a5f41b<br/>4"/]
60["a64543c3<br/>#quot;Signed by Clinical Trial Inc.#quot;"]
1 -->|subj| 2
2 -->|subj| 3
3 -->|subj| 4
4 -->|subj| 5
5 -->|subj| 6
5 --> 7
7 -->|pred| 8
7 -->|obj| 9
9 -->|subj| 10
9 --> 11
11 -->|pred| 12
11 -->|obj| 13
3 --> 14
14 -->|pred| 15
14 -->|obj| 16
16 -->|subj| 17
16 --> 18
18 -->|pred| 19
18 -->|obj| 20
16 --> 21
21 -->|pred| 22
21 -->|obj| 23
3 --> 24
24 -->|pred| 25
24 -->|obj| 26
26 -->|subj| 27
26 --> 28
28 -->|pred| 29
28 -->|obj| 30
26 --> 31
31 -->|pred| 32
31 -->|obj| 33
3 --> 34
34 -->|pred| 35
34 -->|obj| 36
36 -->|subj| 37
36 --> 38
38 -->|pred| 39
38 -->|obj| 40
36 --> 41
41 -->|pred| 42
41 -->|obj| 43
3 --> 44
44 -->|pred| 45
44 -->|obj| 46
46 -->|subj| 47
46 --> 48
48 -->|pred| 49
48 -->|obj| 50
46 --> 51
51 -->|pred| 52
51 -->|obj| 53
1 --> 54
54 -->|pred| 55
54 -->|obj| 56
56 -->|subj| 57
56 --> 58
58 -->|pred| 59
58 -->|obj| 60
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:red,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:red,stroke-width:3.0px
style 5 stroke:red,stroke-width:3.0px
style 6 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 7 stroke:red,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px
style 9 stroke:red,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px
style 11 stroke:red,stroke-width:3.0px
style 12 stroke:#55f,stroke-width:3.0px
style 13 stroke:#55f,stroke-width:3.0px
style 14 stroke:red,stroke-width:3.0px
style 15 stroke:#55f,stroke-width:3.0px
style 16 stroke:red,stroke-width:3.0px
style 17 stroke:#55f,stroke-width:3.0px
style 18 stroke:red,stroke-width:3.0px
style 19 stroke:#55f,stroke-width:3.0px
style 20 stroke:#55f,stroke-width:3.0px
style 21 stroke:red,stroke-width:3.0px
style 22 stroke:#55f,stroke-width:3.0px
style 23 stroke:#55f,stroke-width:3.0px
style 24 stroke:red,stroke-width:3.0px
style 25 stroke:#55f,stroke-width:3.0px
style 26 stroke:red,stroke-width:3.0px
style 27 stroke:#55f,stroke-width:3.0px
style 28 stroke:red,stroke-width:3.0px
style 29 stroke:#55f,stroke-width:3.0px
style 30 stroke:#55f,stroke-width:3.0px
style 31 stroke:red,stroke-width:3.0px
style 32 stroke:#55f,stroke-width:3.0px
style 33 stroke:#55f,stroke-width:3.0px
style 34 stroke:red,stroke-width:3.0px
style 35 stroke:#55f,stroke-width:3.0px
style 36 stroke:red,stroke-width:3.0px
style 37 stroke:#55f,stroke-width:3.0px
style 38 stroke:red,stroke-width:3.0px
style 39 stroke:#55f,stroke-width:3.0px
style 40 stroke:#55f,stroke-width:3.0px
style 41 stroke:red,stroke-width:3.0px
style 42 stroke:#55f,stroke-width:3.0px
style 43 stroke:#55f,stroke-width:3.0px
style 44 stroke:red,stroke-width:3.0px
style 45 stroke:#55f,stroke-width:3.0px
style 46 stroke:red,stroke-width:3.0px
style 47 stroke:#55f,stroke-width:3.0px
style 48 stroke:red,stroke-width:3.0px
style 49 stroke:#55f,stroke-width:3.0px
style 50 stroke:#55f,stroke-width:3.0px
style 51 stroke:red,stroke-width:3.0px
style 52 stroke:#55f,stroke-width:3.0px
style 53 stroke:#55f,stroke-width:3.0px
style 54 stroke:red,stroke-width:3.0px
style 55 stroke:#55f,stroke-width:3.0px
style 56 stroke:red,stroke-width:3.0px
style 57 stroke:#55f,stroke-width:3.0px
style 58 stroke:red,stroke-width:3.0px
style 59 stroke:#55f,stroke-width:3.0px
style 60 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke:red,stroke-width:2.0px
linkStyle 2 stroke:red,stroke-width:2.0px
linkStyle 3 stroke:red,stroke-width:2.0px
linkStyle 4 stroke:red,stroke-width:2.0px
linkStyle 5 stroke-width:2.0px
linkStyle 6 stroke:green,stroke-width:2.0px
linkStyle 7 stroke:#55f,stroke-width:2.0px
linkStyle 8 stroke:red,stroke-width:2.0px
linkStyle 9 stroke-width:2.0px
linkStyle 10 stroke:green,stroke-width:2.0px
linkStyle 11 stroke:#55f,stroke-width:2.0px
linkStyle 12 stroke-width:2.0px
linkStyle 13 stroke:green,stroke-width:2.0px
linkStyle 14 stroke:#55f,stroke-width:2.0px
linkStyle 15 stroke:red,stroke-width:2.0px
linkStyle 16 stroke-width:2.0px
linkStyle 17 stroke:green,stroke-width:2.0px
linkStyle 18 stroke:#55f,stroke-width:2.0px
linkStyle 19 stroke-width:2.0px
linkStyle 20 stroke:green,stroke-width:2.0px
linkStyle 21 stroke:#55f,stroke-width:2.0px
linkStyle 22 stroke-width:2.0px
linkStyle 23 stroke:green,stroke-width:2.0px
linkStyle 24 stroke:#55f,stroke-width:2.0px
linkStyle 25 stroke:red,stroke-width:2.0px
linkStyle 26 stroke-width:2.0px
linkStyle 27 stroke:green,stroke-width:2.0px
linkStyle 28 stroke:#55f,stroke-width:2.0px
linkStyle 29 stroke-width:2.0px
linkStyle 30 stroke:green,stroke-width:2.0px
linkStyle 31 stroke:#55f,stroke-width:2.0px
linkStyle 32 stroke-width:2.0px
linkStyle 33 stroke:green,stroke-width:2.0px
linkStyle 34 stroke:#55f,stroke-width:2.0px
linkStyle 35 stroke:red,stroke-width:2.0px
linkStyle 36 stroke-width:2.0px
linkStyle 37 stroke:green,stroke-width:2.0px
linkStyle 38 stroke:#55f,stroke-width:2.0px
linkStyle 39 stroke-width:2.0px
linkStyle 40 stroke:green,stroke-width:2.0px
linkStyle 41 stroke:#55f,stroke-width:2.0px
linkStyle 42 stroke-width:2.0px
linkStyle 43 stroke:green,stroke-width:2.0px
linkStyle 44 stroke:#55f,stroke-width:2.0px
linkStyle 45 stroke:red,stroke-width:2.0px
linkStyle 46 stroke-width:2.0px
linkStyle 47 stroke:green,stroke-width:2.0px
linkStyle 48 stroke:#55f,stroke-width:2.0px
linkStyle 49 stroke-width:2.0px
linkStyle 50 stroke:green,stroke-width:2.0px
linkStyle 51 stroke:#55f,stroke-width:2.0px
linkStyle 52 stroke-width:2.0px
linkStyle 53 stroke:green,stroke-width:2.0px
linkStyle 54 stroke:#55f,stroke-width:2.0px
linkStyle 55 stroke:red,stroke-width:2.0px
linkStyle 56 stroke-width:2.0px
linkStyle 57 stroke:green,stroke-width:2.0px
linkStyle 58 stroke:#55f,stroke-width:2.0px
Additional validation could be done to ascertain that specific protocols such as double-blind data collection had been followed, signed either by the clinical trial or some third-party verifier.
Part Four: The COVID-19 Appendix
This final use case looks at some of the problems with public-health data that were highlighted during the height of the COVID crisis.
11. Nadia Goes Viral (Herd Privacy)
- Use Case: Nadia wants to support the public health of COVID Contact Tracing without revealing her location.
- Privacy Benefits: Nadia’s location is never revealed.
- Openness Benefits: A large, discrete public-health system is able to share in data.
Contact tracing became critically important during the height of the COVID-19 pandemic. Some of this was done in an analog manner, such as recordings of names and phone numbers at restaurants, so that everyone could be contacted if a COVID case was discovered. More automated digital tracing occurred through use the mobile phones and GPS records.
The problem (which was a recurring one throughout the pandemic) was that there was no consideration for privacy.
Hashed elision of data provides one way to create that privacy. If using GPS coordinates, the user’s data itself might be elided, but if a more sophisticated system were able to instead correlate GPS coordinates to physical addresses, those addresses could be standardized, elided, and still matched through hashes.
Example data might include:
"ur:crypto-pubkeys/lftaadfwhdcxdwjemhpaiopfzoneayzemutlsblychlkfpytmtcnpfonssuojzdpendprfbdenmytaaddmhdcxreglstcyjpmuiatojksgbncenehttkgawlckmkhylfkkmedpwfftlydaptuokihkmnjnospk" [
"addressFor": "1684922400" [
"address": "70 Pine Street Ground Floor, New York, NY 10005"
"dailySalt": "nNyhg9Hpz6b0g48Y1LJ1"
]
"arrivalTime": "1684994608"
"departureTime": "1685000074"
"hasCOVID": "0"
]
graph LR
1(("21e218bb<br/>NODE"))
2["c85d1216<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxdwjemhpaio…#quot;"]
3(["1dbe4323<br/>ASSERTION"])
4["95ebd3f6<br/>#quot;arrivalTime#quot;"]
5["a674df1a<br/>#quot;1684994608#quot;"]
6(["589f9525<br/>ASSERTION"])
7["7f6d5166<br/>#quot;departureTime#quot;"]
8["f7fb221d<br/>#quot;1685000074#quot;"]
9(["7cc9e036<br/>ASSERTION"])
10["dbe0d353<br/>#quot;addressFor#quot;"]
11(("a0ffd70b<br/>NODE"))
12["fc53cc56<br/>#quot;1684922400#quot;"]
13(["c2bf5d15<br/>ASSERTION"])
14["c205d610<br/>#quot;address#quot;"]
15["38d80833<br/>#quot;70 Pine Street Ground Floor, New York, N…#quot;"]
16(["e37dd06d<br/>ASSERTION"])
17["a1cfec80<br/>#quot;dailySalt#quot;"]
18["a1eeef3e<br/>#quot;nNyhg9Hpz6b0g48Y1LJ1#quot;"]
19(["bbb31cf5<br/>ASSERTION"])
20["b897f141<br/>#quot;hasCOVID#quot;"]
21["4e1195df<br/>#quot;0#quot;"]
1 -->|subj| 2
1 --> 3
3 -->|pred| 4
3 -->|obj| 5
1 --> 6
6 -->|pred| 7
6 -->|obj| 8
1 --> 9
9 -->|pred| 10
9 -->|obj| 11
11 -->|subj| 12
11 --> 13
13 -->|pred| 14
13 -->|obj| 15
11 --> 16
16 -->|pred| 17
16 -->|obj| 18
1 --> 19
19 -->|pred| 20
19 -->|obj| 21
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:#55f,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:#55f,stroke-width:3.0px
style 6 stroke:red,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:#55f,stroke-width:3.0px
style 9 stroke:red,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px
style 11 stroke:red,stroke-width:3.0px
style 12 stroke:#55f,stroke-width:3.0px
style 13 stroke:red,stroke-width:3.0px
style 14 stroke:#55f,stroke-width:3.0px
style 15 stroke:#55f,stroke-width:3.0px
style 16 stroke:red,stroke-width:3.0px
style 17 stroke:#55f,stroke-width:3.0px
style 18 stroke:#55f,stroke-width:3.0px
style 19 stroke:red,stroke-width:3.0px
style 20 stroke:#55f,stroke-width:3.0px
style 21 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke-width:2.0px
linkStyle 2 stroke:green,stroke-width:2.0px
linkStyle 3 stroke:#55f,stroke-width:2.0px
linkStyle 4 stroke-width:2.0px
linkStyle 5 stroke:green,stroke-width:2.0px
linkStyle 6 stroke:#55f,stroke-width:2.0px
linkStyle 7 stroke-width:2.0px
linkStyle 8 stroke:green,stroke-width:2.0px
linkStyle 9 stroke:#55f,stroke-width:2.0px
linkStyle 10 stroke:red,stroke-width:2.0px
linkStyle 11 stroke-width:2.0px
linkStyle 12 stroke:green,stroke-width:2.0px
linkStyle 13 stroke:#55f,stroke-width:2.0px
linkStyle 14 stroke-width:2.0px
linkStyle 15 stroke:green,stroke-width:2.0px
linkStyle 16 stroke:#55f,stroke-width:2.0px
linkStyle 17 stroke-width:2.0px
linkStyle 18 stroke:green,stroke-width:2.0px
linkStyle 19 stroke:#55f,stroke-width:2.0px
It of course should be signed:
{
"ur:crypto-pubkeys/lftaadfwhdcxdwjemhpaiopfzoneayzemutlsblychlkfpytmtcnpfonssuojzdpendprfbdenmytaaddmhdcxreglstcyjpmuiatojksgbncenehttkgawlckmkhylfkkmedpwfftlydaptuokihkmnjnospk" [
"addressFor": "1684922400" [
"address": "70 Pine Street Ground Floor, New York, NY 10005"
"dailySalt": "nNyhg9Hpz6b0g48Y1LJ1"
]
"arrivalTime": "1684994608"
"departureTime": "1685000074"
"hasCOVID": "0"
]
} [
verifiedBy: Signature
]
graph LR
1(("c8f3780d<br/>NODE"))
2[/"53e030f3<br/>WRAPPED"\]
3(("21e218bb<br/>NODE"))
4["c85d1216<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxdwjemhpaio…#quot;"]
5(["1dbe4323<br/>ASSERTION"])
6["95ebd3f6<br/>#quot;arrivalTime#quot;"]
7["a674df1a<br/>#quot;1684994608#quot;"]
8(["589f9525<br/>ASSERTION"])
9["7f6d5166<br/>#quot;departureTime#quot;"]
10["f7fb221d<br/>#quot;1685000074#quot;"]
11(["7cc9e036<br/>ASSERTION"])
12["dbe0d353<br/>#quot;addressFor#quot;"]
13(("a0ffd70b<br/>NODE"))
14["fc53cc56<br/>#quot;1684922400#quot;"]
15(["c2bf5d15<br/>ASSERTION"])
16["c205d610<br/>#quot;address#quot;"]
17["38d80833<br/>#quot;70 Pine Street Ground Floor, New York, N…#quot;"]
18(["e37dd06d<br/>ASSERTION"])
19["a1cfec80<br/>#quot;dailySalt#quot;"]
20["a1eeef3e<br/>#quot;nNyhg9Hpz6b0g48Y1LJ1#quot;"]
21(["bbb31cf5<br/>ASSERTION"])
22["b897f141<br/>#quot;hasCOVID#quot;"]
23["4e1195df<br/>#quot;0#quot;"]
24(["b271b9dd<br/>ASSERTION"])
25[/"9d7ba9eb<br/>3"/]
26["6eed6ce0<br/>Signature"]
1 -->|subj| 2
2 -->|subj| 3
3 -->|subj| 4
3 --> 5
5 -->|pred| 6
5 -->|obj| 7
3 --> 8
8 -->|pred| 9
8 -->|obj| 10
3 --> 11
11 -->|pred| 12
11 -->|obj| 13
13 -->|subj| 14
13 --> 15
15 -->|pred| 16
15 -->|obj| 17
13 --> 18
18 -->|pred| 19
18 -->|obj| 20
3 --> 21
21 -->|pred| 22
21 -->|obj| 23
1 --> 24
24 -->|pred| 25
24 -->|obj| 26
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:red,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:red,stroke-width:3.0px
style 6 stroke:#55f,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:red,stroke-width:3.0px
style 9 stroke:#55f,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px
style 11 stroke:red,stroke-width:3.0px
style 12 stroke:#55f,stroke-width:3.0px
style 13 stroke:red,stroke-width:3.0px
style 14 stroke:#55f,stroke-width:3.0px
style 15 stroke:red,stroke-width:3.0px
style 16 stroke:#55f,stroke-width:3.0px
style 17 stroke:#55f,stroke-width:3.0px
style 18 stroke:red,stroke-width:3.0px
style 19 stroke:#55f,stroke-width:3.0px
style 20 stroke:#55f,stroke-width:3.0px
style 21 stroke:red,stroke-width:3.0px
style 22 stroke:#55f,stroke-width:3.0px
style 23 stroke:#55f,stroke-width:3.0px
style 24 stroke:red,stroke-width:3.0px
style 25 stroke:#55f,stroke-width:3.0px
style 26 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke:red,stroke-width:2.0px
linkStyle 2 stroke:red,stroke-width:2.0px
linkStyle 3 stroke-width:2.0px
linkStyle 4 stroke:green,stroke-width:2.0px
linkStyle 5 stroke:#55f,stroke-width:2.0px
linkStyle 6 stroke-width:2.0px
linkStyle 7 stroke:green,stroke-width:2.0px
linkStyle 8 stroke:#55f,stroke-width:2.0px
linkStyle 9 stroke-width:2.0px
linkStyle 10 stroke:green,stroke-width:2.0px
linkStyle 11 stroke:#55f,stroke-width:2.0px
linkStyle 12 stroke:red,stroke-width:2.0px
linkStyle 13 stroke-width:2.0px
linkStyle 14 stroke:green,stroke-width:2.0px
linkStyle 15 stroke:#55f,stroke-width:2.0px
linkStyle 16 stroke-width:2.0px
linkStyle 17 stroke:green,stroke-width:2.0px
linkStyle 18 stroke:#55f,stroke-width:2.0px
linkStyle 19 stroke-width:2.0px
linkStyle 20 stroke:green,stroke-width:2.0px
linkStyle 21 stroke:#55f,stroke-width:2.0px
linkStyle 22 stroke-width:2.0px
linkStyle 23 stroke:green,stroke-width:2.0px
linkStyle 24 stroke:#55f,stroke-width:2.0px
The signature not only provides validation, but allows for automated
updating of the Envelope (with hasCOVID equal to 1 if necessary!)
at a later point, provided that the pubkey and signature continue to
match.
A Envelope like this would be generated for each close locale that someone stays at for more than a few minutes. The keypairs that identify the person would be constantly changing, generated by HD (Hierarchical Deterministic) Key algorithms, providing the user with easy access to the whole set of them while maintaining their non-correlatability.
This would probably be sufficient to maintain privacy, but as an additional protection, location data can also be elided:
{
"ur:crypto-pubkeys/lftaadfwhdcxdwjemhpaiopfzoneayzemutlsblychlkfpytmtcnpfonssuojzdpendprfbdenmytaaddmhdcxreglstcyjpmuiatojksgbncenehttkgawlckmkhylfkkmedpwfftlydaptuokihkmnjnospk" [
"addressFor": ELIDED
"arrivalTime": "1684994608"
"departureTime": "1685000074"
"hasCOVID": "0"
]
} [
verifiedBy: Signature
]
graph LR
1(("c8f3780d<br/>NODE"))
2[/"53e030f3<br/>WRAPPED"\]
3(("21e218bb<br/>NODE"))
4["c85d1216<br/>#quot;ur:crypto-pubkeys/lftaadfwhdcxdwjemhpaio…#quot;"]
5(["1dbe4323<br/>ASSERTION"])
6["95ebd3f6<br/>#quot;arrivalTime#quot;"]
7["a674df1a<br/>#quot;1684994608#quot;"]
8(["589f9525<br/>ASSERTION"])
9["7f6d5166<br/>#quot;departureTime#quot;"]
10["f7fb221d<br/>#quot;1685000074#quot;"]
11(["7cc9e036<br/>ASSERTION"])
12["dbe0d353<br/>#quot;addressFor#quot;"]
13a0ffd70b<br/>ELIDED
14(["bbb31cf5<br/>ASSERTION"])
15["b897f141<br/>#quot;hasCOVID#quot;"]
16["4e1195df<br/>#quot;0#quot;"]
17(["b271b9dd<br/>ASSERTION"])
18[/"9d7ba9eb<br/>3"/]
19["6eed6ce0<br/>Signature"]
1 -->|subj| 2
2 -->|subj| 3
3 -->|subj| 4
3 --> 5
5 -->|pred| 6
5 -->|obj| 7
3 --> 8
8 -->|pred| 9
8 -->|obj| 10
3 --> 11
11 -->|pred| 12
11 -->|obj| 13
3 --> 14
14 -->|pred| 15
14 -->|obj| 16
1 --> 17
17 -->|pred| 18
17 -->|obj| 19
style 1 stroke:red,stroke-width:3.0px
style 2 stroke:red,stroke-width:3.0px
style 3 stroke:red,stroke-width:3.0px
style 4 stroke:#55f,stroke-width:3.0px
style 5 stroke:red,stroke-width:3.0px
style 6 stroke:#55f,stroke-width:3.0px
style 7 stroke:#55f,stroke-width:3.0px
style 8 stroke:red,stroke-width:3.0px
style 9 stroke:#55f,stroke-width:3.0px
style 10 stroke:#55f,stroke-width:3.0px
style 11 stroke:red,stroke-width:3.0px
style 12 stroke:#55f,stroke-width:3.0px
style 13 stroke:#55f,stroke-width:3.0px,stroke-dasharray:5.0 5.0
style 14 stroke:red,stroke-width:3.0px
style 15 stroke:#55f,stroke-width:3.0px
style 16 stroke:#55f,stroke-width:3.0px
style 17 stroke:red,stroke-width:3.0px
style 18 stroke:#55f,stroke-width:3.0px
style 19 stroke:#55f,stroke-width:3.0px
linkStyle 0 stroke:red,stroke-width:2.0px
linkStyle 1 stroke:red,stroke-width:2.0px
linkStyle 2 stroke:red,stroke-width:2.0px
linkStyle 3 stroke-width:2.0px
linkStyle 4 stroke:green,stroke-width:2.0px
linkStyle 5 stroke:#55f,stroke-width:2.0px
linkStyle 6 stroke-width:2.0px
linkStyle 7 stroke:green,stroke-width:2.0px
linkStyle 8 stroke:#55f,stroke-width:2.0px
linkStyle 9 stroke-width:2.0px
linkStyle 10 stroke:green,stroke-width:2.0px
linkStyle 11 stroke:#55f,stroke-width:2.0px
linkStyle 12 stroke-width:2.0px
linkStyle 13 stroke:green,stroke-width:2.0px
linkStyle 14 stroke:#55f,stroke-width:2.0px
linkStyle 15 stroke-width:2.0px
linkStyle 16 stroke:green,stroke-width:2.0px
linkStyle 17 stroke:#55f,stroke-width:2.0px
Despite the elision of the addresses, the standardization of the hashes allows for two addresses to be correlated when it’s discovered that there was COVID at a location.
Meanwhile, the use of a dailySalt ensures that there isn’t an easy
way to create large-scale correlation. The hash for each location will
change each day based on the random Salt. Particularly if this Salt is
kept internal to the public-health agency, determining what locations
relate to which hashes becomes nearly impossible.
This is what creates herd privacy: not only are the individuals protected by their HD keys, but the locations are protected from unwarranted recognition as viral hotspots, unless some of the infected individuals identify them.
The final hurdle for a privacy-focused contact tracer of this sort is how to communicate outbreaks. Having the public agency reach out to the individuals is likely the most effective means of transmitting information, and could perhaps be managed with some sort of anonymous email or messaging. However, asking users to regularly poll the contract-tracing server, querying against their various public keys is likely to be the best privacy-preserving – though it would itself require Tor or something other privacy-preserving query mechanism.
Obviously, the question is a difficult one, but the elision of Gordian Envelope and the ability to match elided hashes provide a strong foundation for contract tracing with a privacy bent.