Using Partial Reconfiguration in Cryptographic Applications: An Implementation of the IDEA Algorithm

This paper shows that partial reconfiguration can notably improve the area and throughput of symmetric cryptographic algorithms implemented in FPGAs. In most applications the keys are fixed during a cipher session, so that several blocks, like module adders or multipliers, can be substituted for their constant-operand equivalents. These counterparts not only are faster, but also use significantly less resources. In this approach, the changes in the key are performed through a partial reconfiguration that modifies the constants. The International Data Encryption Algorithm (IDEA) has been selected as a case-study, and JBits has been chosen as the tool for performing the partial reconfiguration. The implementation occupies an 87% of a Virtex XCV600 and achieves a throughput of 8.3 GBits/sec.