A novel test for unique decipherability of codes
János Falucskai · Publicationes Mathematicae Debrecen · 2011
Having a set C of codewords wi we have to decide whether there are two or more sequences of codewords which form the same chain of characters of codewords.A code C is UD (uniquely decipherable) code, if every message has at most one factorization with respect to code C, that is, if x1x2 . . .xn = y1y2 . . .ym holds, where x1, x2, . . ., xn, y1, y2, . . ., ym ∈ C, then n = m and x1 = y1, . . ., xn = yn.We have developed an algorithm that solves this problem by using finite automata in [1].In this paper we suppose that there is no empty string in the set of coded messages.Thus, we investigate the language C + .In these cases the automata have more states, but we get more applicable results.