Block Ciphers Based on Modular Arithmetic
Joan Daemen, René Govaerts, Joos P. L. Vandewalle · 1993
The block ciphers PES and IPES were originally designed with the ambition to become the successor of DES as a standard. In this paper we point out why this would be a bad idea. On one hand a new block cipher (called MMB) is proposed, that uses similar primitive operations as (I)PES but can be more efficiently implemented both in hardware and in software. On the other hand classes of weak keys (with size up to 2^51) have been found for IPES.