Hardware architecture for elliptic curve cryptography and lossless data compression

Data compression and cryptography play an important role when transmitting data across a public computer network. While compression reduces the amount of data to be transferred or stored, cryptography ensures that data is transmitted with reliability and integrity. Compression and encryption have to be applied in the correct way: data are compressed before they are encrypted. If it were the opposite case the result of the cryptographic operation would be illegible data and no patterns or redundancy would be present, leading to very poor or no compression. In this research work, a hardware architecture that joins lossless compression and public-key cryptography for secure data transmission applications is discussed. The architecture consists of a dictionary-based lossless data compressor to compress the incoming data, and an elliptic curve cryptographic module that performs two EC (elliptic curve) cryptographic schemes: encryption and digital signature. For lossless data compression, the dictionary-based LZ77 algorithm is implemented using a systolic array aproach. The elliptic curve cryptosystem is defined over the binary field F2m , using polynomial basis, affine coordinates and the binary method to compute an scalar multiplication. While the model of the complete system was implemented in software, the hardware architecture was described in the Very High Speed Integrated Circuit Hardware Description Language (VHDL). A prototype of the architecture was implemented on a Xilinx Virtex II Field Programmable Gate Array (FPGA) device. Two advantages of combining lossless compression and public-key encryption were demonstrated: 1) the improvement in the cryptographic module by reducing the amount of data to be encrypted, and 2) a better utilization of the available bandwidth when encrypted data is transmitted across a public computer network.