Explanation of G-DES-DESX

Question

Give a brief explanation of the term G-DES, DESX.

Answer 1

G-DES was invented by Schaumuller-Bichl to enhance on the performance of DES through defining a cipher based upon DES with a larger block size, but devoid of the increase in amount of computation needed. It was claimed that G-DES was as safe as DES since the cipher was based upon DES. But, Shamir and Biham showed that G-DES with the suggested parameter sizes is easily broken and which any alterations of G-DES parameters which result in a cipher faster than DES are less safe than DES.