Stream Cipher Systems Using aChaotic Sequence of I.I.D Random Variables i.i.d.

Abstract- Asequence of i.i.d. binary random variables has found significant applica-tions in modern digital communication systems, such as aspreading spectrum sequence for a DS/CDMA system and akey-stream sequence for astream cipher system. In this paper, after reviewing the generation method of sequences of i.i.d. binary random variables gener-ated by chaotic dynamics we give astream cipher system using asequence of i.i.d. binary random variables which has cryptographic resistance for several kinds of cryptanalysis based on correlation functions. $\mathrm{K}\mathrm{e}\mathrm{y}\mathrm{w}\mathrm{o}\mathrm{r}\mathrm{d}_{\mathrm{S}}-\mathrm{s}\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{a}\mathrm{m} $ cipher, keystream sequences, random sequence, i.i.d. sequence, chaotic dynamics, Cryptanalysis, aut0-/cross-correlation function, secret key 1Introduction Asequence of independent and identically distributed $(i.i.d.) $ binary random variables $[1]-[4]$ has found significant applications in modern digital communication systems such as in spread spectrum (SS) communication systems [5] or cryptosystems $[6, 7] $ as well as in computational applications requiring random numbers $[8, 9] $. Such abinary sequence can be generated in various ways. Nevertheless, linear feedback shift register (LFSR) sequences which hav