BMCSeparate integrity from confidentiality
A record can be resistant to undetected alteration without being private. These are different properties. Integrity concerns whether information has changed; confidentiality concerns who can read it. A sensible identity architecture considers both, alongside availability, access and the ability to manage a record through its useful life.
Blockchain can be part of a system for recording events and checking integrity. Its usefulness depends on the design of that system: what is recorded, who participates, who can inspect the record and how the surrounding applications are secured. The label alone does not answer those questions.
Decide what belongs in the record
Identity documents contain sensitive information. Before using any durable ledger, consider whether the underlying document needs to appear there at all. Some designs keep documents in controlled storage and use a separate reference or cryptographic commitment to help check a record’s integrity. This is an architectural option, not a description of every implementation.
A reference is not automatically anonymous. Whether information can be linked to a person depends on the record and the surrounding data. Assess what different participants can learn, including when several pieces of information are combined.
Plan for change and retention
Identity information may become outdated, a document may expire or a person may correct an error. A useful design should show which record is current and how a correction is represented. Preserving evidence of an earlier event should not make an obsolete detail appear to be the latest truth.
Retention also needs an explicit plan. Long-lived records can create difficult choices when information is no longer needed. Consider those choices before deployment, together with the storage model, access controls and applicable requirements. Avoid assuming that permanent storage is always the right outcome.
Evaluate the complete system
Ask how credentials and keys are managed, how access is reviewed, how recovery works and who responds when something goes wrong. The interfaces around a ledger can be just as important as the ledger itself.
The goal is useful, trustworthy evidence with clear boundaries. Record integrity and privacy should be designed together, rather than treating one as a substitute for the other.