Multi-Factor Authentication (MFA), often coupled with Key Exchange (KE), offers very strong protection for secure communication and has been recommended by many major governmental and industrial bodies for use in highly sensitive applications. Instantiations of the MFA concept vary in practice and in the research literature and various efforts in designing secure MFA protocols have proven unsuc...

Attribute-based encryption (ABE) enables encryption of messages under access policies so that only users with attributes satisfying the policy can decrypt the ciphertext. In standard ABE, an arbitrary number of colluding users, each without an authorized attribute set, cannot decrypt the ciphertext. However, all existing ABE schemes rely on concrete cryptographic assumptions such as the hardnes...

Recent advances in quantum computing and the announcement by the National Institute of Standards and Technology (NIST) to define new standards for digital-signature, encryption, and keyestablishment protocols increased interest in post-quantum cryptographic schemes. This paper introduces Kyber (part of the CRYSTALS – Cryptographic Suite for Algebraic Lattices – package that will be submitted to...

We propose the TWEAKEY framework with goal to unify the design of tweakable block ciphers and of block ciphers resistant to related-key attacks. Our framework is simple, extends the key-alternating construction, and allows to build a primitive with arbitrary tweak and key sizes, given the public round permutation (for instance, the AES round). Increasing the sizes renders the security analysis ...

Motivated by recent developments in fully homomorphic encryption, we consider the folklore conjecture that every semanticallysecure bit-encryption scheme is circular secure, or in other words, that every bit-encryption scheme remains secure even when the adversary is given encryptions of the individual bits of the private-key. We show the following obstacles to proving this conjecture: 1. We co...

Hierocrypt-L1 is a 64-bit block cipher with a 128-bit key. It was selected among the Japanese e-Government 2003 recommended ciphers list and has been reselected in the 2013 candidate recommended ciphers list. In this work, we cryptanalyze Hierocrypt-L1 in the single-key setting. In particular, we construct a 5 S-box layers distinguisher that we utilize to launch a meet-in-the-middle attack on 8...

The new symmetric cipher S-box construction based on matrix power function is presented. The matrix consisting of plain data bit strings is combined with three round key matrices using arithmetical addition and exponent operations. The matrix power means the matrix powered by other matrix. The left and right side matrix powers are introduced. This operation is linked with two sound one-way func...

Encoded lookup tables used in white-box cryptography are known to be vulnerable to power analysis due to the imbalanced encoding. This means that the countermeasures against white-box attacks can not even defend against gray-box attacks. For this reason, those who want to defend against power analysis through the white-box cryptographic implementation need to find other ways. In this paper, we ...

This paper presents a construction of compactly supported dual functions of a given box spline in L2(IR ). In particular, a concrete method for the construction of compactly supported dual functions of bivariate box splines of increasing smoothness is provided. Key-Words:multivariate biorthogonal wavelets, multivariate wavelets, box splines, matrix extension

Although all current scientific white-box approaches of standardized cryptographic primitives are broken, there is still a large number of companies which sell “secure” white-box products. In this paper, we present a new approach to assess the security of white-box implementations which requires neither knowledge about the look-up tables used nor any reverse engineering effort. This differentia...