Question

I have a hash and the full decrypted plaintext of that hash. I am planning on trying to brute force it, it’s a SHA-1 FIPS 180-2 hash.

So my question is, what is the fastest way of doing this? I was thinking about decrypting the data and comparing it to the known plaintext, but then I thought it may be faster to try to hash the decrypted data and compare it to the known hash.
Hopefully the above makes sense, but just incase, the main question is this:

Plaintext : The quick brown fox jumps over the lazy dog
Hash : 2FD4E1C67A2D28FCED849EE1BB76E7391B93EB12

Is is faster to try to hash Plaintext, and compare it to the hash, or decrypt Hash and compare it to Plaintext? Any advice on how to speed up recovery of the key is appreciated. This is just me playing about, I know it would take forever to find the key, but if it were possible to do in a small amount of time (HUUUUGE computing power), how would you do do it?

Answer 1

I have a hash and the full decrypted plaintext of that hash. I am
planning on trying to brute force it, it’s a SHA-1 FIPS 180-2 hash.

So you have the hash and the plaintext?

Find an implementation of SHA and verify it. That is all you can do.