There are different techniques for crypto attacks, one is the brute force attack
, another technique works with prefabricated dictionaries. Both techniques have disadvantages which are evident in the computation time. In the brute force attack, it is the key length
thatdrives up the computation time exorbitantly, while in the dictionary method, it is the generation of the same and the memory capacity
required for the same. Hellman, after whom the Diffie-Hellman algorithm is named, has proposed a compromise between the two extremes - the computation time and the memory space required - with the Time Memory Trade-Off (TMTO). In this method, the dictionary is stored only partially or compressed and the cryptanalysis computes the missing key parts.