Encryption / Description Alphanumeric 16 digits

[eluser]WanWizard[/eluser]
Hashing != Encryption.

Altough you could say that the encoding bit is similar, hashes can not be decoded. Hashes are used in lookup tables, and therefore you have to deal with duplicates. Depending on the hash algorithm and entropy of the input, collisions are more or less likely. If you then shorten the hash, you increase the chance of collisions.

If you encode, you don't have to do a lookup, so duplicates are not an issue.

The only point I was trying to make is that encoding/decoding is pretty expensive (CPU and depending on the algorithm also memory), so from a performance point of view you want to avoid encryption if possible.