This response does not answer the question directly, but asks the AM to evaluate what is trying to be accomplished.

You will not get the randomness in your seed that you are expecting. Your seed will always be '10' (at least for the next ~ 34000000 seconds). Even if you use DentArthurDent's suggestion, you are still only using 100 out of 64*64 possible salts, because you are ignoring 54 (I think) other valid characters which can randomize the salt.

To randomize the salt a little more, you may want to use some form of pack to convert time() into a base64 string, and use that as your salt.

Update: Fixed DentArthurDent's name. Sorry :)

Update-2: Fixed Speelink mesteaks.