CRYx-BCU: A security oriented cost-conscious SoPC implementation for Bus Coupling Units of the European Installation Bus

In this article a low-cost KNX-Secure system is presented. It takes advantage from the facilities that the new in-system Flash FPGAs provide: an unique code for each device (DNA) and internal One-Time-Programmable registers. The well known AES-GCM cryptographic and authentication algorithm in combination with a key generated into the FPGA is proposed for the device dependent code ciphering. The modules that are involved in this security approach are detailed, and the whole protocol for code generation and check is presented. An implementation of this system on a Spartan3-AN FPGA is reported and discussed.