Stupid idea:
Have backups as nostr encrypted self messages, with keys derived from main key?
You can now restore wallet backups in cashu.me thanks to nostr:npub1dgesr3zcgyjv2z0050h7auzdlf88gycry7tlk7wsypmgngy97yxqv4mccn 's PR
The backup can be restored in the welcome page when you first open the wallet (with a fresh state only). You can also drag&drop the backup file in there.
Beware: this is a stateful backup (after every transaction)! We're also working on a single-seed backup from which your ecash can be restored with the help of the mint.
Discussion
Not stupid at all, I was joking about that today! Wanna help build it? :)
Does this reveal # of a user's txs + timing leaks?
it shouldn't reveal anything at all. maybe the changes in the size of the backup needs some consideration like padding.