New SeedSigner experiment: initial support for BIP-352 Silent Payments! * Generate your shareable, reusable payment addr * Export the signing key's pubkey * Export the scanning key's privkey #bip352

Quick overview: #bip352 requires TWO private keys: 1. The scanning key. Must be loaded into a hot wallet in order to scan utxos to find incoming payments. 2. The signing key. Obviously you want to keep this offline and airgapped (hello, @SeedSigner!).

BIP-352 specifies derivation paths for generating each key as a child of a common root key. That means: load a single seed into @SeedSigner as usual and use it to generate the #bip352 scanning AND signing child keys.

I only built support for SETTING UP an airgapped #bip352 silent payments wallet. I still have to dig into how the SPENDING side works and what specific support @SeedSigner might need in order to sign those txs.

Also I am NOT an expert in any of this and there's a decent chance I've done something dumb. Please check my work!

And here's my work-in-progress dev branch:

Cool, #selentium and my code are generating the same #bip352 payment address derived from the same mnemonic backup! External verification / replication is always a big confidence booster that I implemented things correctly!

Whoops, it's #silentium.

@SeedSigner very cool! we are working on a standard for <scan key, spend pub>, stay tuned 😁 also, worth mentioning this is functionally equivalent to an xpub! anyone who has it can see but not spend your outputs

@SeedSigner Ah, awesome. A descriptor-ish format makes more sense than the piecemeal workflow I built in above.

@SeedSigner