Data minimization principles apply to many scenarios. Major use cases include:

1. Age Verification: Proving someone is over 21 without revealing exact birthdate.
2. Professional Credentials: Demonstrating qualifications without exposing personal history.
3. Financial Verification: Proving financial capacity without revealing account details.
4. Identity Authentication: Verifying identity without exposing the full identity document.
5. Collaboration: Sharing relevant expertise without unnecessary personal disclosure.

General Use Cases

Many use cases fall into one of two general categories: contextual information sharing and progressive trust.

Contextual Information Sharing

Data minimization allows creating different views of the same identity for different contexts:

1. Public Context - Share minimal, non-sensitive information
   • Basic identifiers and public credentials
   • General domain expertise
   • No personal details or private information
2. Professional Context - Share relevant professional information
   • Domain-specific credentials
   • Relevant experience and skills
   • Professional history without personal details
3. Trusted Context - Share more comprehensive information
   • Detailed professional background
   • Specific methodologies and approaches
   • Limited personal context relevant to the relationship

This contextual approach mirrors how we naturally share different levels of information in different social contexts in the physical world.

Progressive Trust Development

Data minimization also enables progressive trust—revealing more information as relationships develop. The following example shows how XIDs might be used to offer increasing amounts of information over time.

1. Initial Contact: Share only basic information.

   "BRadvoc8" [
      "name": "BRadvoc8"
      "publicKeys": ur:crypto-pubkeys/hdcx...
      ELIDED (5)
   ]
   

2. Building Relationship: Reveal professional information.

   "BRadvoc8" [
      "name": "BRadvoc8"
      "publicKeys": ur:crypto-pubkeys/hdcx...
      "domain": "Distributed Systems & Security"
      "experienceLevel": "8 years professional practice"
      ELIDED (3)
   ]
   

3. Growing Trust: Share more specific professional details.

   "BRadvoc8" [
      "name": "BRadvoc8"
      "publicKeys": ur:crypto-pubkeys/hdcx...
      "domain": "Distributed Systems & Security"
      "experienceLevel": "8 years professional practice"
      "skillAreas": "API security, Zero-knowledge systems, Protocol design"
      ELIDED (2)
   ]
   

4. Established Trust: Reveal detailed perspectives and methods.

   "BRadvoc8" [
      "name": "BRadvoc8"
      "publicKeys": ur:crypto-pubkeys/hdcx...
      "domain": "Distributed Systems & Security"
      "experienceLevel": "8 years professional practice"
      "skillAreas": "API security, Zero-knowledge systems, Protocol design"
      "potentialBias": "Particular focus on privacy-preserving systems"
      "methodologicalApproach": "Security-first, user-focused development"
   ]
   

This staged approach allows relationships to develop naturally, with information sharing matching the level of established trust—just as we share different levels of personal information at different stages of relationships in the physical world.