## 2 Related Work
The pseudo-random number generator frequently changes the MTEA key in each round. [PERSON] and [PERSON] proposed an algorithm [36] based on the principles of many-valued logic and variable block length. The encryption process is performed iteratively with five rounds. The number of rounds can be varied, with round 1 consisting of gamma and permutations procedures, remaining rounds include substitution and gamma procedures. The proposed method can process binary information after representing as a ternary vector. But there is no method developed that does this conversion directly. LEA (lightweight encryption algorithm) is a block encryption algorithm [37] that is designed to provide confidentiality in lightweight environment like mobile devices. This algorithm uses plain text of 128 bits and varying modes can be selected depending on the size of the key (128, 192, or 256 bits). Based on the modes, the number of rounds can be changed between 24, 28, and 32 bits. This algorithm does not use S-box, instead addition, rotation and XOR arithmetic operation is processed in 32-bit unit [38]. [PERSON] et al. proposed a super-encryption cryptography [39] with IDEA (international data encryption algorithm) and WAKE (word auto key encryption) algorithm. The technique of super encryption combines two or more symmetric cryptographic algorithms so as to provide more security to data. [PERSON] et al. proposed the serpent algorithm [40] that was an AES candidate. The main aim of this algorithm is to maximize the avalanche effect within the cipher text. Serpent has substitution permutation structure that uses 128-bit plain text and accepts keys of 128, 192, or 256 bits. The 32 rounds of serpent make it a bit slower and complex to implement on small blocks. Data encryption standard (DES) is one of the widely used symmetric key block cipher that uses the Feistel structure. The plaintext of 64-bit and a key size of 56 bits are used for the encryption process that includes 16 rounds. The DES algorithm does not allow flexibility in Feistel structure and hence does not support any changes in it [41]. Tiny encryption algorithm (TEA) developed by [PERSON] and [PERSON] [42] is the most efficient for use with embedded devices in IoT networks compared to all the discussed encryption algorithms. Some of the interesting features of TEA are ease of implementation, the absence of specialized tables, good performance and short enough to integrate into any embedded device. The main focus of TEA is reduced memory usage and maximized speed. Encryption routine of TEA is shown in Figure 1 and the decryption routine is shown in Figure 2.  
TEA uses Feistel structure with 64 rounds or 32 cycles where one cycle is composed of two rounds [43]. The plaintext block size is 64 bits (operate on two 32-bit unsigned integers and stored in v[0] and v[1]). The recommended key size is 128 bits. The key is split into four 32-bit blocks, k[0] to k[3]. The XOR and AND operations are used alternatively. Also repeated mixing of all the bits of plaintext and key is achieved by the dual shift operation. A simple key schedule is used for both encryption and decryption and the four 32-bit blocks of the key are mixed exactly the same way for each cycle. Magic constant is used to compute the key. For preventing the attacks caused by the symmetry of rounds, each cycle (one cycle constitutes of two rounds) uses different multiples of magic constants. Magic constant is 2,654,435,769 or 9E3779B9\({}_{16}\) and would be selected as \(2^{31}/\ O\) (\(\O\) is named the golden ratio). During the encryption process, the plaintext is partitioned into two parts Left[0] and Right[0]. Each of the parts utilizes another half part for doing the encryption process. There will be 64 rounds along with two other rounds that constitute one cycle, so there are 32 cycles. After the 64\(th\) round, both parts will be composed to create the cipher text.