User Database Password Encryption

Encrypted. Always.

Both e-mail and FTP passwords are encrypted with the MySQL ENCRYPT function in our databases.

I also use this kind of thinking when creating websites that use a username and password to log in.

Only encrypted / hashed (edited due to witty comments below ;) ).

Dovecot and exim4 were a bit of a fiddle to get working correctly with php's sha1(), but no complaints about the less standards-compliant clients (yet).

You forgot to add hashed (sha1, md5, etc.).

Encryption(two way can be decrypted back into original password):

plaintextpassword->encryptionkey->encryptedpassword

encryptedpassword->encryptionkey->plaintextpassword

Hashing (supposedly one way):

plaintextpassword->hashedpassword+anyextrastuffyouwanttoaddinlikesalt->finalhashedpassword

finalhashedpassword->nowaytogetfinalhashedpasswordinplaintextunlessyoualreadyknowwhattheplaintextpasswordisalready

The only way to get the password would be to come up with the plain text equivalent of the hashed value, even if you do not have the original there is a change that you might come into another plaintext value that has the same hash eventually.

@Internat:

Do you store your user passwords in plaintext or encrypted
When I come across an unsalted, non-hashed plaintext password…I'm frankly staggered.

@jed:

@Internat:

Do you store your user passwords in plaintext or encrypted
When I come across an unsalted, non-hashed plaintext password…I'm frankly staggered.

I just say ….. keeps me employed ;)

Exactly, storing plain text passwords is completely irresponsible. I also feel that sotoring encrypted passwords should be avoided if at all possible (they can still be compromised if the key leaks and the administrator still has access to all his users' passwords).

Hashed and salted with sha1 or better is the way to go. And make sure you use a unique salt for each password, otherwise the purpose of the salt will be defeated.