Consider whether VerifiableTimestamp and TimestampCommitment are both needed

sgreenbury commented 1 year ago

Qs:

VerifiableTimestamp looks very similar to TimestampCommitment; are both needed?
the verify_content method in VerifiableTimestamp verifies the expected data in the DID commitment; is this the cleanest way to do it? (at least this is validating the content, not verifying it)
why not have VerifiableTimestamp as a trait (without the verify_content method), which is implemented by TimestampCommitment?
most importantly, how do we make sure that the validate_pow_hash is called as part of the content verification procedure?

First step will be to draw a diagram of the commitments & related traits.

thobson88 commented 1 year ago

UML diagram

Traits in green. Structs in orange.

DID-Verification drawio (2)

thobson88 commented 1 year ago

Done in PR #105.

VerifiableTimestamp has been turned into a trait, which is a wrapper for a pair of independent commitments, one committing to DID document content and the other to a timestamp.

The verify method in VerifiableTimestamp has a default implementation which verifies each of the two commitments against the same target hash, thereby confirming that the timestamp is immutably associated with the DID document content.

thobson88 commented 1 year ago

Updated UML diagram (after refactoring)

refactored-DID-Verification drawio

sgreenbury commented 1 year ago

Closed with #108

alan-turing-institute / trustchain

Consider whether VerifiableTimestamp and TimestampCommitment are both needed #102

UML diagram

Updated UML diagram (after refactoring)