CRYPTANALYSIS OF THE HAGELIN C-52 AND SIMILAR MACHINES A KNOWN PLAINTEXT ATTACK
H. Paul Greenough · Cryptologia · 1999
A known plaintext attack is presented for the Hagelin C-52 and similar machines featuring irregular stepping of the pinwheels. The technique allows the determination of the particular subset of available pinwheels used in the encryption, their order, and the active positions on each pinwheel. Ways of improving the encryption algorithm to defeat the proposed attack are also presented.