Overview
Salting is a critical privacy enhancement for that keeps elided data private. It ensures that even when the same information is elided from multiple documents, the resulting hashes are different, preventing correlation attacks.
Why is Salting Important?
Without salting, elision would have a serious privacy weakness:
- Identical content would produce identical hashes.
- An observer could determine if the same information was elided in multiple documents.
- Common values could be guessed through dictionary attacks.
How Does Salting Work?
Salting solves this problem by adding random data to an Envelope leaf or node before hashing:
Without salt: hash("name": "John Smith") → always the same hash
With salt: hash("name": "John Smith" + random_salt) → different hash each time
Salts should be cryptographically random and of sufficient length.