How can it be impossible to “decrypt” an MD5 hash?

Question

Hello friends,

I was reading a question about MD5, and it made me remember something that boggles me. Very simple question, and I'm sorry if it's not a good one. I just can't understand how you convert something to one thing using some algorithm, and there being no way to convert it back using the algorithm in reverse.

So how is this possible?

Also, since multiple strings can create the same MD5 hash, due to it being less data than the input string, how would any other hashing system be any better?


Thanks..............

Answer 1

Here's a parallel:

Add up the ages of everyone in your family. Only keep the last two digits.

Now tell me everyone's ages based on that one number.

Answer 2

No, there are dictionaries as you say, but no way to decrypt MD5