A Side-channel Attack Resistant Programmable PKC Coprocessor for Embedded Applications

This paper describes the design of a programmable coprocessor for public key cryptography (PKC) on an FPGA. The implementation provides a very broad range of functions together with countermeasures against side-channel analysis (SCA) attacks. The functions are implemented in a hierarchical manner, where all levels are accessible by the user. This makes the coprocessor very flexible and particularly suitable to be used in embedded environments where the border between hardware and software needs to be decided depending on the application. Especially for RSA, the resulting implementation on an XC3S5000 FPGA, from the low-cost Spartan series of Xilinx, shows comparable performance figures compared to the state-of- the-art in PKC coprocessors.