Why two identities?

[FabioPinheiro]

My only point against this did:peer:4 is why complicate everything else with two identities. Other than that I love the idea.

IMO is complicated enough controlling one identity and here we are proposing to identities that come always in pairs:

did:peer:4{{hash}}:{{encoded document}}
did:peer:4{{hash}}

Was it considered to use DID query?
Note the the query part of a DID is not part of the identity! On the contrary of DID path.
(The DID fragment is also not part of the identity but can't be used on the DID Comm message field id.)

did:peer:4{{hash}}?doc={{encoded document}} <=> did:peer:4{{hash}}
Those two are equivalent in terms of identity. According to the DID core specs they are one identity.

[dbluhm]

I recommend raising this discussion on: decentralized-identity/peer-did-method-spec#61