Cost-Effective Architectures for RC5 Brute Force Cracking

In this paper, we discuss the options for brute-force cracking of the RC5 block cipher, that is, for revealing the unknown secret key, given a sample ciphertext and a portion of the corresponding plaintext. First, we summarize the methods employed by the current cracking efforts. Then, we present two hardware architectures for finding the secret key using the “brute force” method. We implement the hardware in FPGA and ASIC and, based on the results, we discuss the cost and time needed to crack the cipher using today’s technology and suggest a minimum key length that can be considered secure.

Searching RC5 Keyspaces with Distributed Reconfigurable Hardware

Abstract — Topic Area: Software. Implementation details and performance measurements for a brute-force RC5 keycrack application executing on a cluster containing commodity reconfigurable hardware are presented. The purpose of the application is to gauge the maximum real-world speedups attainable on a metacomputer that forms the underlying execution platform. The operation of the metacomputer and its associated tools, designed to target cluster-based distributed reconfigurable hardware in a high-level manner, is discussed in detail. Index Terms — Reconfigurable computing, high performance computing, distributed reconfigurable computing