Protecting cryptographic hardware against malicious attacks by nonlinear robust codes

Fault-based attacks against cryptographic circuits must be addressed by techniques that are different from approaches designed for random transient faults. We systematically investigate robust error-detecting codes that specifically target malicious attacks and guarantee minimal bounds on detection probability. Our study is based on FPGA-supported fault-injection campaigns on the circuit implementation of a recent lightweight block cipher and its sub-modules. We quantify the detection capabilities of different robust and non-robust codes with respect to both random faults and malicious attacks, as well as the required overheads. For the first time, we report performance of a novel punctured cubic code on actual cryptographic circuitry. Experimental results show that robust codes with a certain number of redundant bits have better detection properties in security context and higher predictability than their conventional linear counterparts.