A block algorithm that uses a 64-bit key invented by Mr.Shimuzu and Mr.Miyguchi

In cryptography, FEAL (the Fast Data Encipherment Algorithm) is a block cipher proposed as an alternative to the Data Encryption Standard (DES), and designed to be much faster in software. The Feistel based algorithm was first published in 1987 by Akihiro Shimizu and Shoji Miyaguchi from NTT. The cipher is susceptible to various forms of cryptanalysis, and has acted as a catalyst in the discovery of differential and linear cryptanalysis.

Faithful; loyal.