PROPOSAL: version tags for upgradeability

[theblockstalk]

Sometimes system operators need to request that clients update encrypted document data and schemas due to

• bugs
• system upgrades requiring new data, linking or reprocessing of data

This requires that encrypted storage layers (servers, mobile devices) keep track of the version of schema and data they are using to an appropriate level. With this information, data schema and data upgrade functions can be requested applied only when relevant.

This proposal is to create version tags on data, specified by system operators:

• plain text metadata stored beside the encrypted document and/or;
• encrypt metadata stored beside encrypted document (not sure if/how this could work) and/or;
• within the encrypted document (therefore can only be read by clients)

Additional feature: Version tags could be numeric, Datetimes or string labels, specified by system operators. Suggest starting with numeric.

[OR13]

hmm, i think JOSE handles this for us automatically regarding the encryption envelope, but its possible to apply a plaintext version and an encrypted index version as well.

[msporny]

Having versions on each document might turn into a nightmare. Having a vault with multiple different document versions is problematic. So, -1 to that.

If we are going to put a version on something, it should be the vault config.

... but what might be better is feature discovery and a commitment to backwards compatibility.

[dmitrizagidulin]

Discussed on Jun 10, 2021 call.

• @OR13 is right, no need to version the encrypted document format (since it's always JWEs).
• Adding a version field to the Vault Config document might be useful though.
• However, if spec changes are additive (and non-breaking - see HTML for example), versioning is not needed, and instead, you can do Feature Discovery. For example, OpenID Connect is a great example of this, it uses feature discovery flags in the config.

Next step: Add to the spec the notion that we're specifically not going after a numeric versioning, and will depend on feature discovery.