Dictionary attack

Dictionary attack

In cryptanalysis and computer security, adictionary attack is a technique for defeating a cipher or authentication mechanism by trying to determine its decryption key or pass phrase by trying hundreds or sometimes millions of likely possibilities, such as words in a dictionary.

Pre-computed dictionary attack/ Rainbow table attack

It is possible to achieve a time-space trade off by pre-computing a list of hashes of dictionary words, and storing these in a database using the hash as the key. This requires a considerable amount of preparation time, but allows the actual attack to be executed faster.