Caesar cipher

Abstract: The Hill cipher is a classical symmetric encryption algorithm that succumbs to the know-plaintext attack. Although its vulnerability to cryptanalysis has rendered it unusable in practice, it still serves an important pedagogical role in cryptology and linear algebra. In this paper, a variant of the Hill cipher is introduced that makes the Hill cipher secure while it retains the efficiency. The proposed scheme includes a ciphering core for which a cryptographic protocol is introduced.

Abstract: is the process of scrambling a message so that only the intended recipient can read it. With the fast progression of digital data exchange in electronic way, Information Security is becoming much more important in data storage and transmission. Caesar cipher is a mono alphabetic cipher. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter. In this paper, author modified the traditional Caesar cipher and fixed the key size as one. Another thing alphabet index is checked if the alphabet index is even then increase the value by one else alphabet index is odd decrease the key value by one. Encryption and scrambling of the letters in the Cipher Text.

Abstract: In this paper the authors present a new integrated symmetric-key cryptographic method, named SJA, which is the combination of advanced Caesar Cipher method, TTJSA method, Bit wise Rotation and Reversal method. The encryption method consists of three basic steps: 1) Encryption Technique using Advanced Caesar Cipher, 2) Encryption Technique using TTJSA Algorithm, and 3) Encryption Technique using Bit wise Rotation and Reversal. TTJSA Algorithm, used in this method, is again a combination of generalized modified Vernam Cipher method, MSA method and NJJSAA method. Nath et al. already developed some symmetric key encryption methods namely MSA, DJSA, DJJSA, modified DJJSA, NJJSA, TTJSA, TTSJA, DJMNA, UES-I, UES-II etc. The cryptanalysis shows that TTJSA is free from standard cryptographic attacks such as differential attack, plain text attack or any brute force attack. In the present method the authors have used advanced modified Caesar Cipher method where the authors have modified the standard Caesar Cipher method and then they applied TTJSA method to make the entire crypto system very hard to break. The present method has been tested on different plain text specially with repeated character and the spectral analysis of the plain text and the encrypted is also been shown. The spectral analysis shows that the present cryptography method, SJA can not be broken with any kind of standard cryptography attack. The authors propose that the present method will be most suitable for password, SMS or any kind of small message encryption.