Delo naj predstavi matematične osnove, potrebne za razumevanje tokovnih šifer, ki se uporabljajo v kriptografiji (simetrični, generatorji psevdo-naključnih števil) in Linear Feedback Shift Register - LFSR (opišite zvezo med periodo in karakterističnim polinomom). Glavna cilja sta predstavitev urno-kontroliranih pomičnih šifer (angl. Clock-Controled Shift Register) in napad z omejenimi vložitvami (angl. Constrained Embedding Attack). Preučite njihove konstrukcije, varnost ter učinkovite implementacije.

Literatura:

A. Menezes, P. van Oorschot and S. Vanstone, Handbook of Applied Cryptography, CRC Press (Series on Discrete Mathematics and its Applications), 4th ed, 1999.

J. DJ. Golić, Constrained embedding probability for thwo binary strings, Siam. J. Discr. Math. 9/3, (1996), 360-364.

J. DJ. Golić, L. O'Connor, Embedding and probabilistic Correlation Attacks on Clock-Controled Shift Register, Advances in cryptology, EUROCRYPT'94, LNCS 950 (1995), 230-243,

J. DJ. Golić, L. O'Connor, A cryptanalysis of clock-controlled shift registers with multiple steps, Cryptography: policy and algorithms (Brisbane, 1995), LNCS 1029 (1996), 174--185,

M. V. "Zivković, An algorithm for the Initial State Reconstruction of the Clock-Controled Shift Register, IEEE Trans. Inform. Theory 37/6 (1991), 1707-1716.