TOTAL: TRNG on-the-fly testing for attack detection using Lightweight hardware

We present a design methodology for embedded tests of entropy sources. These tests are necessary to detect attacks and failures of true random number generators. The central idea of this work is to use an empirical design methodology consisting of two phases: collecting the data under attack and finding a useful statistical feature. In this work we focus on statistical features that are implementable in lightweight hardware. This is the first paper to address the design of on-the-fly tests based on the attack effects. The presented design methodology is illustrated with 2 examples: an elementary ring-oscillator based TRNG and a carry-chain based TRNG. The effectiveness of the tests was confirmed on FPGA prototypes.