-In this paper we present some new approach for security enhancement of well known classical substitution cipher (Playfair and Hill cipher). Some drawback inherent the 5x5 Playfair cipher which adversely affect the security of this cipher and also Hill Cipher that succumbs to the known-plaintext attack .It is clear from above line due to some serious security reasons we cannot use these well kn...

Motivation • Cryptographic constructions based on lower-level primitives are often analyzed by modeling the primitive as an ideal object – Sometimes, impossible to construct based on standard assumptions – Here: hash functions from block ciphers • When instantiated, the primitive may have " defects " and be far from ideal Motivating example • Related-key attacks on block ciphers – Several such ...

This paper proposes an improved public key encryption algorithm based on Chebyshev polynomials. On the base of the semi-group property of Chebyshev polynomials, we import the alternative multiply coefficient i K to forge the ciphertext tactfully which can make the cipher text-only aattack out of work. The chosen of i K is decided by the value of ( ( )) mod r s T T x N , and the number of i K ca...

We experiment with the block cipher proposed by Hoang, Morris, and Rogaway [3], even though the cipher is insecure [8]. The cipher is based on swap-or-not shu e, and we call it the Shu e Block Cipher. We show how the cipher can be translated into SMT-LIB v2 format, suitable for automated solving by SMT solvers. We compare performance of various SMT solvers on the encryption and known plaintext ...

The MISTY1 block cipher has a 64-bit block length, a 128-bit user key and a recommended number of 8 rounds. It is a Japanese CRYPTREC-recommended e-government cipher, an European NESSIE selected cipher, and an ISO international standard. Despite of considerable cryptanalytic efforts during the past fifteen years, there has been no published cryptanalytic attack on the full MISTY1 cipher algorit...

LBlock is a lightweight block cipher proposed in ACNS 2011. It has 64-bit block size and 80-bit key size which is the typical parameter setting accpeted by most of the recent proposed lightweight block ciphers. It has fast hardware implementation efficiency and it still remains rather secure considering the recent results and the security margin it provides. In this paper, we investigate the di...

This report presents a new statistical attack on iterative block ciphers called the correlation attack which is a natural generalization of linear cryptanalysis. The attack is based on nding complex-valued functions on the input and the output of a cipher which have a high correlation. Their mutual relation is then exploited to yield information about the nal round key. Introducing the notions ...

Modular Multiplication based Block Cipher (MMB) is a block cipher designed by Daemen et al. as an alternative to the IDEA block cipher. In this paper, we give a practical-time attack on the full MMB with adaptive chosen plaintexts and ciphertexts. By the constructive sandwich distinguisher for 5 of the 6 rounds of MMB with amazingly high probability 1, we give the key recovery attack on the ful...

The RC4 is a stream cipher widely deployed in software applications due to its simplicity and efficiency. The paper presents a cryptanalytic attack that employs the tree representation of this cipher and introduces an abstraction in the form of general conditions for managing the information about its internal state. In order to find the initial state, the tree of general conditions is searched...