A new approach to block cipher design

In this paper we apply the cryptographic finite state machine approach as introduced in [1] to the design of symmetric key block ciphers. Key words in the design approach are simplicity, uniformity, parallelism, distributed nonlinearity and high diffusion. 3-Way is a block cipher with a block and key length of 96 bits. Key components in the construction of 3-Way are a 3-bit nonlinear S-box and a linear mapping that can be described by modular polynomial multiplication in ℤ₂12. The arrangement of the components allows software implementations in the range of 10 Mbit/s on a modern PC and dedicated hardware implementations above 1 Gbit/s using standard technology (1.2μ CMOS). The cipher structure of 3-Way is shown to be surprisingly strong with respect to both linear and differential cryptanalysis.