A simple construction of encryption for a tiny domain message

In modern cryptography, message encryption is an important tool for providing data-privacy and authenticity. In many applications, it is used such as password storage, data integrity check, wireless network, automated teller machine card, and credit card. Usually, the size of a message is arbitrary. In addition, many techniques and constructions are available for the variable and fixed size of message encryption. Interestingly, we address the issue of small domain message encryption (SDE). Generally, the existing constructions are based on blockcipher such as AES/DES and scratch function. Hence, these solutions are reasonable for the bigger size of data. However, these are heavy and expensive for the small size of message encryption under the platform of Internet of Technology-end device (IoT), and resource constrained devices. In addition, the size of plaintext and ciphertext should be equal for satisfying the property of small domain encryption. Actually, J.Black and P.Rogaway formally addressed the above issues for the first time. Following that certain schemes have been launched under the SDE such as Mix-and-Cut shuffle, Swap-or-Not, Thorp-Shuffle, and FNR. Moreover, Sometimes-Recursive shuffle (SRS) is the pioneer construction yet in respect of low encryption time. However, it needs to execute 1000 calls of AES for achieving full security. Therefore, the construction of SRS is also heavy and expensive for the IoT environment and resource constrained devices. Under these circumstances, we propose a simple scheme that follows by Fiestel structure. The internal format is based on small keyed-function. Our construction can encrypt small size of a message. Furthermore, the size of plaintext and ciphertext are equal.