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Why people are so frightend of storing the salt & hash of the user password? May be I am mistaken but if the salt is unique for each hash it is almost imposible to recover the original password. Of course you must use a well proven encription library but it is trivial. Am I missing something?



Yes, you are missing one thing: if you are storing that file, a security breach (several kinds of those) means an attacker can get that file. Are you thinking this is not a problem? Think again!

* For "moderately" strong passwords (say, ones which need 10,000 attempts to get), getting at your encrypted files means the difference between you being able to throttle-and-disable a serial guesser and having the password hacked (bonus points if that was the password your user uses on other sites with the same usernames.) * An attacker can go over the file to find "extremely" easy password for some user. * A determined attacker can test hundreds of millions of passwords for a specific user, and know when he succeeded, before you ever notice it. So unless your website has a "change password every year" policy, the attacker can breach even "moderately strong" passwords.

This is even before issues like "well proven encryption libraries" are still broken, and if the one you used is broken, your file is still out there.

This doesn't mean that it cannot be done, with enough care -- but it does mean that if you avoid doing it, it's a big relief, and a big potential crisis averted.


please correct me if I'm wrong: you are not storing passwords, you are storing hashes & salts. One different long random salt for each password.

In my database I store hashes obtained with Blowfish:

http://derekslager.com/blog/posts/2007/10/bcrypt-dotnet-stro...

How many tries would you have to do to guess it? And for the other passwords you have to start all over again.


Who is frightened of that? The problem discussed here is with managing logins information for different sites, not hashing on the server side.


He talks about it as a nightmare wich implies that storing emails/hashes is worse.

I think that storing them is not more difficult, it is more convenient and secure (of course this is relative). But maybe I am missing something about the security of this scheme.




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