Miss-in-the-Middle Attack

Related Concepts

Block Ciphers

Definition

Following the idea behind the meet-in-the-middle approach, the miss-in-the-middle attack is one of the techniques to construct distinguishers for the impossible differential attack. The idea is that one finds two events that propagate half way through the cipher top and bottom with certainty, but which do not match in the middle. This results in an event which is impossible for the full cipher, i.e., has zero probability. A typical tool for constructing such events would be truncated differentials. Note that it is sufficient that events contradict each other in a single bit in the middle.

Background

This technique was first introduced in the papers by Biham et al. [1,  2] to cryptanalyze round-reduced versions of Skipjack, IDEA, and Khufu.