Design and implementation of a SoC-based security coprocessor and program protection mechanism for WSN

The practical applications of wireless sensor networks in vulnerable areas require the communication data of sensor devices confidentiality, integrity and freshness. Furthermore the program data of sensor devices need to be protected. In this paper, we present the design, implementation and simulation of an effective hardware security coprocessor namely RC5-FKM and program protection mechanism based on system on chip (SoC) technology for wireless sensor networks (WSN). Compared with existing works, the unique features of our design includes: (1) a design of fingerprint based key management (FKM) is implemented in SoC, which is used to build secret keys for cryptographic coprocessor. (2) A program protection mechanism is proposed to prevent the program data from being read out by system intruders so as to improve the security of program data in sensor device. (3) A reusable optimized logic cell (ROTL) including some adders and registers is implemented in RC5-FKM, which results in the elimination or minimization of the additional hardware overhead. The design is mapped on FPGA and ASIC design. Results show that the hardware overhead of our design is 9.6% less than previous designs and the execution time of our hardware design is only 0.2% of that of general processors and shorter than other AES coprocessors.