HCCA: A Cryptogram Analysis Algorithm Based on Hill Climbing

Abstract

The single letter substitution encryption is the basis of the most widely encryption methods in cryptography. Therefore, it is extremely significant for the development of the cryptography to decipher this kind of encryption efficiently and correctly. Researchers elaborately analyzed the features of frequency analysis algorithm and the pattern matching algorithm as well as combined the strengths of each algorithm. Aiming at the circumstance that the cryptogram transmission channel has some noise interference, researchers finally designed a cryptanalysis algorithm HCCA based on hill climbing algorithm, according to the statistical regularities of nature language and the pattern characteristic of different words, which is on basis of the two algorithms mentioned above. The results of experiment showed that the cryptanalysis algorithm HCCA could decrypt the substitution cipher efficiently and correctly. In addition, the cryptanalysis algorithm HCCA could still complete the decryption work correctly under the circumstance, and there exists some noise interference in different degrees.