DRIL– A Flexible Architecture for Blowfish Encryption Using Dynamic Reconfiguration, Replication, Inner-Loop Pipelining, Loop Folding Techniques

Blowfish is used in a wide variety of applications, involving large amounts of data, demanding high-speed encryption, flexible key sizes and various encryption modes. Even though the ASIC implementations have better encryption speeds and throughput than FPGA ones, their flexibility is restricted. In blowfish, key generation and encryption stages function disjointedly rendering it suitable for dynamic reconfiguration. Fiestal network of the algorithm is better suited for inner loop pipelining and loop folding. Combining these architectural features with dynamic reconfiguration and replication results in a proficient architecture for blowfish described in this paper as the DRIL architecture. This four-tier architecture, involving both hardware and software designs, focuses on efficient hardware utilization, higher throughput, flexibility and better performance. Further, DRIL is a platform independent architecture. Performance evaluation on the XILINX SPARTAN 2E and VIRTEX 2 devices showed very high utilization of the FPGA device with a throughput of 259.615 x R Mbps on SPARTAN 2E and 515.218 x R Mbps on VIRTEX 2 devices, where R is the replication factor.