What is the difference between password, key and hash?
These terms, which are entirely different in cryptography, are often mixed up. Password – is that very word, word combination or meaningless character set which we enter answering some programs’ request. However, these programs do not use passwords for encryption, they just get keys from them. Encryption keys are bit strings (0 or 1) of different length, 40, 64 and 128-bit keys are most widely used. So, to decrypt anything you need to know either password or the key itself. To get a key from a password the hashing operation is often used. Hashing is a rather complicated cryptographic function, which is getting a string of any length at the input and generating a bit-string of fixed length (hash) at the output. It has to main characteristics: even a minor modifying of the input string leads to complete change of the output hash value; and it’s practically impossible to find the input string knowing the hash value.
