time memory trade-off (crypto analytics) (TMTO)

There are different techniques for crypto attacks, one is the brute force attack, another technique works with ready-made dictionaries. Both techniques have disadvantages, which can be seen in the computing time.

In the case of the brute-force attack, it is the key length that drives up the computing time exorbitantly; in the case of the dictionary method, it is the generation of the same and the storage capacity required for it.

Hellman, after whom the Diffie-Hellman algorithm is named, proposed a compromise between the two extremes - the computing time and the required storage space - 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.