actually, i might have misunderstood, if you just meant cracking hashes then you just need to look them up in online hash dictionaries or attack it with a dictionary, it's pretty simple, but it only works if the pass or thing you're trying to decrypt isn't that strong, like if it's a credit card number given that it's just numbers, it just takes a while since it's long, but you could make the first 4 letters static since they just determine the type of card and there are only a couple. if it's a password then it would be harder the longer it is and the more symbols are there, a dictionary covering all password would take a lot of space and time to throw it on the hash