The MICKEY Stream Ciphers. The family of stream ciphers MICKEY (which stands for Mutual Irregular Clocking KEYstream generator) is aimed at resource-constrained hardware platforms. It is intended to have low complexity in hardware, while providing a high level of security. It uses irregular clocking of shift registers, with some novel techniques to balance the need for guarantees on period and pseudorandomness against the need to avoid certain cryptanalytic attacks.