Security against related-key attacks is an important criteria for modern cryptographic constructions. In the related-key setting, the adversary has the ability to query the underlying function on the target key as well as on some related-keys. Although provable security against related-key attack has received considerable attention in recent years, most of the results in the literature aim to a...

Password-Authenticated Key Exchange (PAKE) protocols allow parties to share secret keys in an authentic manner based on an easily memorizable password. Recently, Nam et al. showed that a provably secure three-party passwordbased authenticated key exchange protocol using Weil pairing by Wen et al. is vulnerable to a man-in-the-middle attack. In doing so, Nam et al. showed the flaws in the proof ...

The basic requisites for any steganography algorithm include imperceptibility, embedding capacity and robustness to communication attacks. To measure the quality of gray-scale or color image, the metric such as PSNR is widely used by researchers in steganography. However, for digital color image, there are many other options such as WPSNR, PSNRE, PSNRY, PSNR-HSR, CQM etc. In this paper, we have...

Standard form of authenticated encryption (AE) requires the ciphertext to be expanded by the nonce and the authentication tag. These expansions can be problematic when messages are relatively short and communication cost is high. This paper studies a form of AE scheme whose ciphertext is only expanded by nonce, with the help of stateful receiver which also enables detection of replays. While th...

During Financial Cryptography 2012 Chan et al. presented a novel privacy-protection fault-tolerant data aggregation protocol. Comparing to previous work, their scheme guaranteed provable privacy of individuals and could work even if some number of users refused to participate. In our paper we demonstrate that despite its merits, their method provides unacceptably low accuracy of aggregated data...

In the SPN (Substitution-Permutation Network) structure, it is very important to design a diffusion layer to construct a secure block cipher against differential cryptanalysis and linear cryptanalysis. The purpose of this work is to prove that the SPN structure with a maximal diffusion layer provides a provable security against differential cryptanalysis and linear cryptanalysis in the sense th...

With today’s dissemination of embedded systems manipulating sensitive data, it has become important to equip low-level programs with strong security guarantees. Unfortunately, security proofs as done by cryptographers are about algorithms, not about concrete implementations running on hardware. In this article, we show how to perform security proofs to guarantee the security of assembly languag...

Authenticated encryption schemes establish both privacy and authenticity. This paper specifies a family of the dedicated authenticated encryption schemes, Artemia. It is an online nonce-based authenticated encryption scheme which supports the associated data. Artemia uses the permutation based mode, JHAE, that is provably secure in the ideal permutation model. The scheme does not require the in...

Consider the provable security of RSA-OAEP when not instantiated with random oracles. Suppose a security reduction exists to show that finding a plaintext from a RSA-OAEP ciphertext (breaking the basic OW-CPA security) is as hard as the RSA problem. • The reduction can be used in an adaptive chosen ciphertext text (IND-CCA2) attack against RSA-OAEP. • The reduction cannot succeed in the random ...