3D is a 512-bit Block Cipher whose design is inspired from the Advanced Encryption Standard (AES). Like the AES, each round of 3D is composed of 4 transformations including a round-key addition, a byte-wise substitution, a byte-wise shuffle and an MDS matrix multiplication. In 3D, two distinct byte-wise permutations are employed for odd and even rounds. In this paper, using concepts from graph theory, we design a unified byte permutation for both odd and even rounds with the same diffusion property as the original Cipher. The main advantage of this new transformation is in hardware implementation of the Cipher where with less resources we can speed up the encryption/decryption process.

Impossible differential attack is a well-known mean to examine robustness of Block Ciphers. Using impossible differential cryptanalysis, we analyze security of a family of lightweight Block Ciphers, named Midori, that are designed considering low energy consumption. Midori state size can be either 64 bits for Midori64 or 128 bits for Midori128; however, both versions have key size equal to 128 bits. In this paper, we mainly study security of Midori64. To this end, we use various techniques such as early-abort, memory reallocation, miss-in-the-middle and turning to account the inadequate key schedule algorithm of Midori64. We first show two new 7-round impossible differential characteristics which are, to the best of our knowledge, the longest impossible differential characteristics found for Midori64. Based on the new characteristics, we mount three impossible differential attacks on 10, 11, and 12 rounds on Midori64 with287: 7, 290: 63, and 290: 51 time complexity, respectively, to retrieve the master-key.

Block Ciphers have wide applications for hardware and software implementations. In this paper, a new Block Cipher algorithm with provable security is proposed. The whole structure of the algorithm is novel and has a good encryption and decryption performance. Additionally, it has good security with few number of rounds. The structure of the proposed algorithm consists of 4-rounds Feistel-Like which uses 3-rounds Feistel type functions. Moreover, a new method for MDS (Maximal Distance Separable) Matrix construction is proposed and used in the round function as a linear layer. Furthermore, some considerations in S-Boxes of the algorithm lead to obtaining better algebraic expression than AES S-boxes. The Algorithm has a high margin of security against various cryptanalysis methods due to using specific functions in its round functions. Our theoretical evaluations show that the devised Cipher algorithm has provable security against attacks based on linear and differential cryptanalysis and it is robust against differential, truncated differential, boomerang, and integral cryptanalysis in terms of practical security.

Differential fault analysis, a kind of active non-invasive attack, is an effective way of analyzing cryptographic primitives that have lately earned more attention. In this study, we apply this attack on CRAFT, a recently proposed lightweight tweakable Block Cipher, supported by simulation and experimental results. This Cipher accepts a 64-bit Tweak, a 64-bit plaintext, and a 128-bit key to produce a 64-bit Ciphertext. We assume that the target implementation of CRAFT does not use countermeasures in this paper. The considered fault model in the initial phase of this paper is a single-bit, but random nibble-injected fault, where we first present the fault injection attack as a simulation and then report on how to retrieve the round sub-keys. Next, we use frequency glitch as a fault injection technique in the experimental phase. This part aims to produce a single fault at a nibble in a specific round of the CRAFT. Following our statistical analysis and according to the simulation findings, we can reduce the key space to 30. 28 and 24. 37 bits, respectively, by using 4 and 5 faults. The experimental section also identifies the location of random faults injected by the hardware mechanism.

In this paper, we design a lightweight and modified random key generation for PRESENT Block Cipher which is applicable in the encryption of the digital signals. In the Block Ciphers, the master key is used directly in the encryption process for the data (plaintext). But in this work, a master key (initial key) is used to derive the new random master keys (random session keys) and use these keys for the encryption process. The use of random keys will overcome the brute force attack that can be applied to the PRESENT Cipher. The random session keys generated will produce different Ciphertexts for the same plaintext for every session. In this approach, we take advantage of the Block Cipher to produce random keys. The PRESENT Cipher is shared in both random key generation and encryption process. Therefore, the proposed structure has both random key generation and data encryption in a unified circuit. This property reduces hardware resources. The implementation results, in 180 nm CMOS technologies, show the proposed structure is comparable in terms of area and delay with other works.