This paper describes a generic BIST strategy for devices implementing symmetric encryption algorithms. Taking advantage of the inner iterative structures of crypto-cores, test facilities are easily set-up for circular self-test of the crypto-cores, built-in pseudo-random test generation and response analysis for other cores in the host device. Main advantages of the proposed test implementation are an architecture with no visible scan chain, 100% fault coverage on crypto-cores with negligible area overhead, availability of pseudo-random test sources and very low aliasing response compaction for other cores.