4 ms·
If you encrypt the prior passwords using a key derived from the current password, you're enabling this sort of check on password change without really sacrifici
by ben0x539 6y ago
If you encrypt the prior passwords using a key derived from the current password, you're enabling this sort of check on password change without really sacrificing security, don't you?
- dragonwriter 6y ago> If you encrypt the prior passwords using a key derived from the current password, How can you do that with a prior password if you didn’t store it as plaintext when it was current? You can’t encrypt something you don’t have. Unless you are encrypting the old hash, not the password.
- eropple 6y agoYou would have it during the password change if you did old-new-new_again, yeah?
- ben0x539 6y agoYeah that was the idea. I guess a lot of apps don't actually do that and just email you password reset links, in which case you can't actually recover the old password. :<
- rovr138 6y agoThis leaks data if a collision can be found and exploited. Assuming the user uses the password in other places, this can be a bad thing.