Earticle

Image encryption is one of the most methods of information hiding. A novel secure encryption method for image hiding is presented in this paper. The proposed method provides good confusion and diffusion properties that ensures high security due to mixing the two Boolean operations: XOR and Rotation that are done on the bits of the pixels in the image. This method is implemented by firstly doing a sequential XOR operation on all the bits of pixels in the image, and secondly makes a circular rotate right of these bits. These two operations are repeated many times during the encryption phase. The security and performance of the proposed encryption method have been evaluated by applying it on images and analyze the recorded results using key space analysis, key sensitivity analysis, and statistical analysis. The performance experiments show that the proposed method is promising to use effectively in wide fields of image encryption.

In the existing random grids based (n, n) visual secret sharing (VSS) schemes, decryption is done with the help of human visual system by stacking the cipher grids. The stacking operation is computationally modeled as Boolean OR operation, which suffers from two drawbacks. Firstly, the contrast of the reconstructed image decreases exponentially by increasing n (≥2) and secondly, it requires perfect alignment of stacking the cipher grids. In this paper, we propose Boolean XOR operation as decryption operation for the existing random grids based (n, n) VSS schemes. The proposed operation removes both the drawbacks and does lossless secret reconstruction. We have demonstrated the improvement in the contrast of the reconstructed image by formal proofs and experimental results.

Combining different cryptanalytic methods to attack a cryptosystem became one of the hot topics in cryptanalysis. In particular, algebraic methods in side channel and differential fault analysis (DFA) attracted a lot of attention recently. In [9], Hojśik and Rudolf used DFA to recover the inner state of the stream cipher Trivium which leads to recovering the secret key. For this attack, they required 3.2 one-bit fault injections on average and 800 keystream bits. In this paper, we give an example of combining DFA attacks and algebraic attacks. We use algebraic methods to improve the DFA of Trivium [9]. Our improved DFA attack recovers the inner state of Trivium by using only 2 fault injections and only 420 keystream bits.

This paper presents the first equivalent key recovery attack on H2-MAC-MD5, which conduces to a selective forgery attack directly. H2-MAC is similar with HMAC except that the outer key is omitted. For HMAC-MD5, since the available differential paths are pseudo- collisions, all the key recovery attacks are in the related-key setting, while our attack on H2- MAC-MD5 gets rid of this restriction. Based on the distinguisher of HMAC-MD5 proposed by Wang et al., a pair of intermediate chaining variables, i.e., the equivalent keys ( ˜K , ˜K ′), is detected which fulfils the specific conditions on (IV, IV ′) of the pseudo-collision. Then the inner key recovery attack on HMAC-MD5 explored by Contini and Yin is adopted to recover ( ˜K , ˜K ′). Consequently, the adversary can compute the valid MAC value of M0kM∗ effortlessly, where M0 is a fixed one-block message, and M∗ can be any bit string. Keywords: Cryptanalysis, H2-MAC-MD5, Distinguishing attack, Equivalent key recovery attack

Quantum Key Distribution (QKD) is a secure key sharing technology with unconditional security. Certain well-known protocols for QKD have been presented, which claim their security by means of higher eavesdropping error-rates. A generalized quantum key distribution protocol that can be optimized for arbitrary number of bases and dimensions of photon states is presented in this paper. The protocol can provide higher eavesdropping error-rates than the well-known existing QKD protocols like BB84 [4] and B92 [5]. The higher error-rate makes it possible for Alice and Bob to share secure keys on relatively large distances.

Wireless Sensor Networks have been a great effect in our real life. With its various types of applications WSN is also a matter of concern for its existing vulnerabilities. To prevent those loopholes we need to provide some effective mechanism for providing better security and authentication issues. Wireless Sensor Networks also have a constraint of resources as the nodes work on battery power. In our paper, we have shown such an effective mechanism using a combination of DES and Blowfish in CBC mode for security enhancement which provides high data confidentiality and authentication.