Protočna šifra RC4

RC4 je najpopularnija vrhunska suvremena protočna šifra koju je 1987. godine osmislio Ronald Rivest. Posebnost ove šifre je u njezinoj jednostavnosti te je to jedan od razloga njene izuzetne popularnosti, kako u akademskom, tako i komercijalnom svijetu. Iako je od njenog stvaranja proteklo tridesetak godina, još uvijek je u fokusu istraživanja mnogih kriptoanalitičara diljem svijeta. U ovom radu opisan je opći koncept protočne šifre te je u trećem poglavlju korak po korak predstavljen algoritam RC4, koji se sastoji od dva dijela: KSA i PRGA. U četvrtom i petom poglavlju analizirane su KSA i PRGA.RC4 is the most popular state-of-the-art stream cipher. It was created in 1987 by Ronald Rivest. Specialty of this cipher lies in its simplicity, which is probably one of the main reasons for its popularity in academic and commercial world. Although almost thirty years had passed since its creation, RC4 remains in research focus of many cryptoanalysts. This thesis presents concept of general stream cipher and step-by-step approach of RC4 algorithm in third chapter. RC4 algorithm consists of two parts: KSA and PRGA. Chapters four and five present analysis of KSA and PRGA, respectively