Embedding attacks on step[1.. D ]clock-controlled generators
W.G. Chambers, Dieter Gollmann · Electronics Letters · 2000
In a step[1..D] cryptographic generator a selector determines which bits from a primitive shift-register's output are sent to the final output, the maximum spacing being D. Two attacks are described, one through finding where embeddings are possible, valid for D = 2 and 3, and the other through counting embeddings.