High Speed Networking Security: Design and Implementation of Two New DDP-Based Ciphers

Abstract

Using Data-Dependent (DD) Permutations (DDP) as main cryptographic primitive two new ciphers are presented: ten-round Cobra-H64, and twelve-round Cobra-H128. The designed ciphers operate efficiently with different plaintext lengths, 64 and 128-bit, for Cobra-H64 and Cobra-H128, respectively. Both of them use very simple key scheduling that defines high performance, especially in the case of frequent key refreshing. A novel feature of Cobra-H64 and Cobra-H128 is the use of the Switchable Operations which prevent the weak keys. The offered high-level security strength does not sacrifice the implementation performance, of both ciphers. Architecture, design and hardware implementation of the two ciphers are presented. The synthesis results for both FPGA and ASIC implementations prove that Cobra-H64 and Cobra-H128 are very flexible and powerful new ciphers, especially for high-speed networks. The achieved hardware performance and the implementation area cost of Cobra-H64 and Cobra-H128 are compared with other ciphers, used in security layers of wireless protocols (Bluetooth, WAP, OMA, UMTS and IEEE 802.11). From these comparisons it is proven that the two proposed are flexible new ciphers with better performance in most of the cases, suitable for wireless communications networks of present and future.