Proposal: zcashd emergency recovery phrase support in Argos

[Crackdevs]

Hi @zmanian and @poldsam,

We have been researching the missing recovery path for zcashd emergency recovery phrases and noticed that Argos already has most of the secure scanning and sweeping infrastructure needed.

We are considering contributing support for phrase-only recovery of the legacy zcashd derivation paths, particularly:

• pre-4.7 legacy Sapling recovery;
• post-4.7 Sapling addresses under the legacy 0x7FFFFFFF account;
• legacy transparent address discovery with a gap limit.

We don’t want to build a separate recovery app or duplicate anything already planned in Argos. Would this be useful as a new Argos recovery source, and would you be open to reviewing an external implementation?

We can start with a small regtest PoC that derives and recovers a funded legacy Sapling address from the phrase alone.

Also happy to follow whatever implementation boundary fits Argos best.

[zmanian]

Yes we would be open to reviewing an implementation of these features

[Crackdevs]

Great. Thank you!