SHA0, SHA1, SHA2 (SHA256 and SHA512), MD5 etc. are all 1 way encryption algorithms which means that they cannot be decrypted. You can create something that will generate a random string, hash the string and then compare the 2 hashes. Another thing you need to look at is what hashing technique is used. All of these techniques can look the same. There are limitations.
Lets say the encrypted string is a sentence... If you are testing with random strings. It will be very, very, (did i say very) hard to get a sentence with that. Now another option would be to test with a dictionary file, but these files are usually very large. Currently no collisions for SHA2 have been found. SHA0 can be decrypted. You need lots of processing power to get through lots of tests fast. Even then it will take a long time in order to find it.
Examples (SHA1):
Text >> Hello World!
Hash >> 2ef7bde608ce5404e97d5f042f95f89f1c232871
Text >> Hello World
Hash >> 0a4d55a8d778e5022fab701977c5d840bbc486d0
The difference with and without the '!' is a lot.
I would recommend something that would let you ENCRYPT things. AES encryption is strong and I cant find any tools that can do it for me, for documents at least. This is just my input. Im pretty sure there is other people who actually studied cryptography on this forum.
Theres already software that can brute force hashes.
You must login or register to view this content.