Abstract: We extend some results of Lempel and Restivo on multiset decipherable codes to set decipherable codes. Keywords: Codes, Unique decipherability, Multiset decipherability, Dominoes, Set decipherability. Article: 1. INTRODUCTION In unique decipherable (UD) codes, different sequences of code

strings over a given non-empty finite set A. Let con: A∗ ∗ − → A ∗ be the concatenation map which to every string of strings associates their concatenation. A uniquely decipherable code is a finite set C ⊆ A ∗ such that con is injective on the submonoid C ∗ of A∗ ∗. This submonoid is then isomorphic

We study a number of natural language decipherment problems using unsupervised learning. These include letter substitution ciphers, character code conversion, phonetic decipherment, and word-based ciphers with relevance to machine translation. Straightforward unsupervised learning techniques most

The success of the cryptographic technique during World War II in decoding enemy ciphers holds an enduring impact on archaeologists working on decoding ancient scripts. The con-viction to break open any code, in theory, employing scientific methods, mathematical formulae and computers, gives rise

We attack the problem of deciding whether a finite collection of finite languages is a code, that is, possesses the unique decipherability property in the monoid of finite languages. We investigate a few subcases where the theory of rational relations can be employed to solve the problem

developed an important relation between best 1:1 code and the uniquely decipherable code by using different measures of entropy. Keywords—Codeword, Instantaneous code, Prefix code, Uniquely decipherable code, Best one-one code, Mean codeword length I.

Information- Self information, Shannon’s Entropy, joint and conditional entropies, mutual information and their properties. Discrete Memory less channels: Classification of channels, calculation of channel capacity. Source Coding, and Channels Coding. Unique decipherable Codes, condition of

Information- Self information, Shannon’s Entropy, joint and conditional entropies, mutual information and their properties. Discrete Memory less channels: Classification of channels, calculation of channel capacity. Source Coding, and Channels Coding. Unique decipherable Codes, condition

is exhaustive if and only if equality holds. The McMillan Inequality states that if `1, `2,..., `n are the lengths of the words in some uniquely decipherable code, then the same condition holds. In this note we examine how the Kraft-McMillan Inequality conditions for the existence of a prefix or uniquely

It is shown that for any uniquely decipherable code, with a small cost in the expected coding length we can add constraints on the worst-case coding length. Moreover, this cost is related to the Fibonacci numbers. Keywords: data compression, Fibonacci numbers, Hu#man codes, source coding, uniquely