Matrix Encryption
Craig P. Bauer · 2021
Polygraphic substitution ciphers replace characters in groups, rather than one at a time. Lester Hill is almost always given credit for discovering matrix encryption, but as David Kahn pointed out in his definitive history of the subject, Jack Levine&s;s work in this area preceded Hill&s;s. Levine pursued the approach back in 1961 for the special case in which an involutory matrix was used. A good cipher must resist crib attacks. An intercepted message always has some context that allows an attacker to guess cribs. The Hill cipher is important because of the explicit connection it makes between algebra and cryptography. It is not known to have been important in use. In fact, Jack Levine enjoyed working on it because he didn&s;t have to worry about intersecting classified work.