Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

> 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.



You would have it during the password change if you did old-new-new_again, yeah?


Yeah 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. :<


This 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.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: