security - md5 decoding. How they do it?

Question

i thought, that it is impossible to decode md5 hashes, but i found tools, which decode them here. but i have no idea, how they do it in such a short period of time(it takes about a second).

Help me please to understand it.

Thanks

Answer 1

It doesn't decode an MD5 hash. It uses what's called a rainbow table... That's why it's so important to use salted hashes instead of storing the hash directly...