Although Purple and Enigma, the Japanese and German ciphers, were eventually broken, they did offer some security when they were initially implemented and provided real challenges for American and British cryptanalysts. In fact, had the cipher machines been used properly—without repeated message keys, without cillies, without restrictions on plugboard settings and scrambler arrangements, and without stereotypical messages which resulted in cribs—it is quite possible that they might never have been broken at all.
