Originally posted by adewri
hashed not encrypted thats news...
In oracle (and in unix too):

hash_pwd = TO_HASH(pwd, username)
and not exists (as a mathematic method in nature):
pwd = TO_PWD(hash_pwd, username)

but encription/description has reverse mathematic methods
if u can:
encr_pwd = TO_ENCR(pwd, username)
then must be exists (as a mathematic method):
pwd = TO_DESCR(encr_pwd, username)

NOTE: TO_HASH, TO_PWD, TO_ENCR, TO_DESCR are not real functions
only as example.