Offline password attacks are a way of cracking passwords without being discovered. Since there is no brute forcing to an active service, the risk of detection is a lot less. The aim is to obtain the hashed version of a password and reverse it back to plain text. Different hashing algorithms output different hashes of varying bit lengths. Since hashes are made up of hexadecimal numbers, which are four bits each, identifying a hash bit length would entail counting the number of hexadecimal numbers and multiplying by four.
For example, a hash of 63640264849A87C90356129D99EA165E37AA5FABC1FEA46906DF1A7CA50DB492 contains 64 characters. 64 x 4 = 256. This tells us that the bit length of the hash is 256 bits. In this example, the most common hashing algorithm that would output a 256 bit hash is SHA-256. What if you have a hash that is 128 bits? Here, we have...