compromis temps/mémoire

CONT: The obvious method of attack is brute-force exhaustive search of the key space [which is time consuming] Later it was suggested that a rich and powerful enemy could build a special-purpose computer capable of breaking DES [Data Encryption Standards] by exhaustive search in a reasonable amount of time. Later, Hellman showed a time-memory trade-off that allows improvement over exhaustive search if memory space is plentiful, after an exhaustive precomputation. These ideas fostered doubts about the security of DES.