Towards inter-vendor compatibility of true random number generators for FPGAs

True random number generators (TRNGs) are fundamental constituents of secure embedded cryptographic systems. In this paper, we introduce a general methodology for porting TRNG across different FPGA vendor families. In order to demonstrate our methodology, we applied it to the delay-chain based TRNG (DC-TRNG) on Intel Cyclone IV and Cyclone V FPGAs. We examine vendor-agnostic generality of the underlying DC-TRNG principle and propose modifications to address differences in structure of FPGAs. Implementation of the DC-TRNG on Cyclone IV uses 149 LEs (<;0.1% of available resources) and has a throughput of 5Mbps, while on Cyclone V it occupies 230 ALMs (<;1.5% of resources) with an output rate of 12.5 Mbps. The quality of the random bits produced by the DC-TRNG on Intel Cyclone IV and V is further confirmed by using NIST statistical test suite.