Request: BIP39-style mnemonic output type

dmshaw / paperkey

Print an OpenPGP key on paper for archive and recovery

GNU General Public License v2.0

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Request: BIP39-style mnemonic output type #2

Open shawnz opened 3 years ago

shawnz commented 3 years ago

Hi there, thank you for the very useful tool.

I think it would be helpful if paperkey additionally supported a BIP39-style output format where the data would be encoded as words from a word list rather than hex characters. This might make transcription of the data easier.

jonathancross commented 3 years ago

Note: BIP39 is for a 256bit seed (or smaller), so 4096bit RSA keys would need a LOT of words.

ECC or EdDSA keys would work great though. If a larger wordlist (like that of the EFF Diceware project) were used (12.9 bits per word), we would get a slightly shorter mnemonic than that one in BIP39.

dmshaw commented 3 years ago

Yes, that was my concern about using a wordlist here: hex can be more difficult to type in, but at least fits on a reasonable number of sheets of paper :)

Note that you can always use a wordlist, even with the current version of paperkey, by using "--output-type raw". This is intended for piping to a program to handle different representations of data (QR code, wordlists, etc).

jonathancross commented 3 years ago

Yes, ~ 320 words might be a bit much. But it would still be a great option to have for the Elliptic Curve keys. A backup which relies on 2 different pieces of software is less reliable, and given that Paperkey is apparently pre-installed in TailsOS, it would be ideal if it just worked out of the box.

A few nice features for BIP39 which might help here as well:

uses extra bits as a checksum -- so errors can be detected.
Because the dictionary is fixed, users only need to type in the beginning of each word and it is auto completed.
spelling is nearly impossible to mess up.

Note: Using a mnemonic means we don't need to trust our printer, evil USB cables, etc.