4 ms·

My master password is "public" (I put it in a mail draft, also a note on my phone and printed it out on a piece of paper, just to be sure), and I have 2FA enabl

by haspok 4y ago

My master password is "public" (I put it in a mail draft, also a note on my phone and printed it out on a piece of paper, just to be sure), and I have 2FA enabled via Yubikey. I never really understood why I had to always provide my master password anyway when logging in even on a trusted device, as the whole point of a password vault is to no longer have to remember any passwords... but we are getting there, eventually.

sebk 4y ago
I'm not sure what service you're using, so this might or might not apply to you: Consider that some password managers use MFA to allow you to connect to their online service that will download a synced, encrypted copy of your password vault, but the vault itself is only wrapped with a key derived from your master password. If someone was to obtain a copy of your vault, decrypting it would be trivial with a weak or compromised master password in that case. CTAP supports an extension called hmac-secret that would allow you encrypt your vault, which would mitigate this issue (While introducing others potentially -- for instance, hmac-secret does not require user verification so anyone with your yubikey could decrypt it). Of course there are other mechanisms to encrypt a vault other than a key derived from a password that you can use with a Yubikey, like PGP, but I don't know of any commercial password manager that does it that way.
presto8 4y ago
You bring up good points: ideally, there would be no need to remember a passphrase at all! Especially since the passphrase has to be long and unwieldy in order to be resistant to offline dictionary attack. The thing I worry about is that the security of the passphrase is only as secure as the mechanism guarding it. If it's written on a piece of paper, then how is the paper secured? It could be put in a vault, but then the vault itself is a conspicuous target for thieves. Hiding the paper somewhere is probably pretty reasonable, but if it's too well hidden, it could get forgotten or accidentally thrown out over time. I use a YubiKey as well as an ultimate backup, and it has a PIN code mechanism that will lock after a few incorrect attempts, so that is a reasonable tradeoff for security and usability I feel. I wonder if the best solution is to have a distributed copy of a recovery passphrase to friends and family. Then separately have a distributed copy of the vault itself (in my case, it's GPG-protected Password Store). This must have been an area of study already, I need to do some research!

by haspok 4y ago

sebk 4y ago

I'm not sure what service you're using, so this might or might not apply to you: Consider that some password managers use MFA to allow you to connect to their online service that will download a synced, encrypted copy of your password vault, but the vault itself is only wrapped with a key derived from your master password. If someone was to obtain a copy of your vault, decrypting it would be trivial with a weak or compromised master password in that case. CTAP supports an extension called hmac-secret that would allow you encrypt your vault, which would mitigate this issue (While introducing others potentially -- for instance, hmac-secret does not require user verification so anyone with your yubikey could decrypt it). Of course there are other mechanisms to encrypt a vault other than a key derived from a password that you can use with a Yubikey, like PGP, but I don't know of any commercial password manager that does it that way.

presto8 4y ago

You bring up good points: ideally, there would be no need to remember a passphrase at all! Especially since the passphrase has to be long and unwieldy in order to be resistant to offline dictionary attack. The thing I worry about is that the security of the passphrase is only as secure as the mechanism guarding it. If it's written on a piece of paper, then how is the paper secured? It could be put in a vault, but then the vault itself is a conspicuous target for thieves. Hiding the paper somewhere is probably pretty reasonable, but if it's too well hidden, it could get forgotten or accidentally thrown out over time. I use a YubiKey as well as an ultimate backup, and it has a PIN code mechanism that will lock after a few incorrect attempts, so that is a reasonable tradeoff for security and usability I feel. I wonder if the best solution is to have a distributed copy of a recovery passphrase to friends and family. Then separately have a distributed copy of the vault itself (in my case, it's GPG-protected Password Store). This must have been an area of study already, I need to do some research!