PHP API Key Generator

Question

Does anyone know of any API key generator script/class for PHP? The class should have method generate, that would generate a key and isValid() method, to check if the key is

Answer 1

just use something like this (pseudo code) sha1(salt + time + mac-addr + another salt + some other random data) crc32 or md5 would also work inestead of sha1 and store it in a database and then isValid() checks the db if the key exists?