Linear Cryptanalysis of the Fast Data Encipherment Algorithm

This paper discusses the security of the Fast Data Encipherment Algorithm (FEAL) against Linear Cryptanalysis. It has been confirmed that the entire subkeys used in FEAL-8 can be derived with 225 pairs of known plaintexts and ciphertexts with a success rate approximately 70% spending about 1 hour using a WS (SPARCstation 10 Model 30). This paper also evaluates the security of FEAL-N in comparison with that of the Data Encryption Standard (DES).