On Wed, Dec 26, 2018 at 11:33 AM Aymeric Vitte <vitteaymeric@gmail.com> wrote:

so, even with a tool like yours, they can be misleaded, for example trying a few words to replace the missing/incorrect one, get a valid seed and stay stuck with it forever trying to play with BIP44/49 to find their keys

Just a small detail, but my tool actually looks up all the possible combinations and then finds which one has been used before by looking for past transactions on the blockchain. Therefore, it won't tell you your phrase is correct unless it is a phrase that has actually been used before (preventing what you described).

I saw that your tool was querying blockchain.info, but it cannot guess what derivation path was used and if it is a standard one what addresses were used, and even if successful it works only for bitcoin (so maybe it should just output the ~1500 possible phrases and/or xprv, and be completely offline, this is still doable for people)

Using some algorithm to take some input and generate a bip39 phrase that you can use with any bip39 wallet sounds perfectly reasonable.

I forgot to mention that this can help also solving the "what if something happens to me" case giving to the family the seed and the parameter(s) for the derivation path, or an easy way to find it (better than something like: remind this passphrase, take the sha256 of it, then use some other stuff to find the encryption algo, take n bytes of the hash, use it to decode my wallet or my seed... and then everybody looking at you like crazy)