Abstract

Network security is the primary element to secure a communication network, and if an intruder still able to break this security element, the other and an important element is data encryption which hides the intelligence of data so that other than authorized entities cannot understand the encrypted data. This paper proposed a new shared key, block cipher encryption/decryption algorithm. The algorithm is designed keeping the features of non fiestel cipher and counter mode of block cipher is used in the algorithm. The encryption process starts by entering a key and counter value which is 128-bit long. From the 128-bit of key, decimal value is calculated and added between two counter values to make counter value 128-bit. To encrypt data, 128-bit key is used along with counter value. This new algorithm encrypts 128-bit plaintext block and produces 128-bit cipher text block using several encryption elements including matrix transposition, adding average value, key based bitwise transposition operation, and byte substitution. The algorithm is designed for secure communication applications. For the analysis of proposed algorithm different cryptanalysis techniques such as frequency attack, avalanche effect, throughput time and brute force attack are used, and the design is useful in terms of privacy, data confidentiality. The unique combination of encryption elements obscures the relationship between plaintext and cipher text.