passphrase2pgp VS YubiKey-Guide

As far as I'm aware, Mnemonikey is the first of its kind, rhyming only with the related but conceptually different passphrase2pgp tool, from which I drew my original inspiration.

I think people should seriously consider using something like passphrase2pgp [0] in addition to a hardware key like this. That way you can have a brain key (hopefully generated with diceware or equivalent) to tie together day-to-day keys like this to a more permanent identity. I'm honestly surprised that strategy is not more widespread.

[0] https://github.com/skeeto/passphrase2pgp

Check out Chris Wellons' tool passphrase2pgp - it does exactly what you're describing by hashing an arbitrary input passphrase with Argon2.

So the easiest way to synchronize gpg keys I found is https://github.com/skeeto/passphrase2pgp - it generates a deterministic gpg key (also ssh keys, x509 certificates...) from a passphrase. Excellent tool

One way to circumvent this is to use a strong passphrase to deterministically generate the PGP/SSH key [1] to unlock other passwords. The SSH key could grant access to a remote server with backups and the PGP key could decrypt passwords using pass [2].

1. https://github.com/skeeto/passphrase2pgp

2. https://www.passwordstore.org/

I know there are tools that can generate GPG from arbitrary inputs, but what I'm really looking for is something with direct compatibility with BIP 39 or (BIP 44) phrases in particular.

What if https://github.com/skeeto/passphrase2pgp is not obviously the software to use, or doesn't exist at some later point?

My own tool, passphrase2pgp works this way. It generates both OpenPGP and SSH Ed25519 keys from a user-chosen passphrase, and it's designed to send the key straight into the ssh-agent on demand.

Derive my keypair entirely from a passphrase, with generous key stretching. I never need to worry about backing up my keys. I later extended this idea to OpenPGP and SSH, where I also exclusively use passphrase-derived keys: passphrase2pgp.

passphrase2pgp: for storing my PGP and SSH keys in my brain. Neither ever reside in permanent storage.

Instead, most people generate keypair(s) on an airgapped machine and write them to two Yubikeys. Or write subkeys to a single Yubikey and keep a backup in encrypted form. See https://github.com/drduh/YubiKey-Guide

I'd recommend using the Yubikey as a GPG smartcard[1]. The private key stays on the Yubikey. I also use it for ssh. But make sure you have a backup key or two, just in case the primary Yubikey gives out. FIDO2 and all other regular Yubikey functionality still works with it.

[1]: https://github.com/drduh/YubiKey-Guide

The excellent guide by drduh should be mentioned here: https://github.com/drduh/YubiKey-Guide — I've been using this approach for years to store my OpenPGP keys on Yubikeys and use them for SSH.

I don't generate my keys on devices. That lets me be flexible and keep backups, as well as use the same keys on multiple physical devices. Using a single yubikey is a bad idea, as you're bound to eventually lose it or break it. Hasn't happened to me yet in 5 years, but I expect it to happen.

I followed this guide to generate a master key and three subkey.

See https://github.com/drduh/YubiKey-Guide . Also google for OpenPGP card specifications, they will answer your question

Regarding GPG/SSH keys, there is a great howto: https://github.com/drduh/YubiKey-Guide

I'd be lying if I said I understood all of that. I'm definitely going to do some research ahaha. Someone else on this post sentence this like which they said was very good guide. https://github.com/drduh/YubiKey-Guide

When storing the key on a Yubikey, however, all you need is just the PIN in order to use the key. It can contain numbers, letters, symbols, etc. and can be quite long, so you can treat it as a passphrase for all intents and purposes. There are actually two PIN codes: one regular one, for a read access, and another administrative one, for write access for when you want to modify the gpg applet settings or the key on the Yubikey. There is also a limit to how many times in a row you can enter pins incorrectly, after which the gpg applet gets locked and the only thing you can do is reset it, erasing the PGP keys. See https://github.com/drduh/YubiKey-Guide for more information.

Try follow this guide from DrDuh https://github.com/drduh/YubiKey-Guide/blob/master/README.md