Crypto on PHP

Crypto usage in PHP is simple, but that doesn't mean its free. First of all denpending on the data that you're encrypting, you might have reasons to store a 32-bit valuein the database instead of the 160 bit value to save space. Second the more secure the crypto is, the longer is the computatiom time to deliver the hash value.

The major difference between md5(), crc32() and sha1() is the length of the hash generated.

crc32() generates 32 bit.
sha1() returns 128 bit.
md5() gernerates 160 bit.