We present the homomorphic evaluation of the Prince block cipher. Our leveled implementation is based on a generalization of NTRU. We are motivated by the drastic bandwidth savings that may be achieved by scheme conversion. To unlock this advantage we turn to lightweight ciphers such as Prince. These ciphers were designed from scratch to yield fast and compact implementations on resource-constr...

A block cipher, such as the DES cipher, is used to encrypt binary plaintext in discrete blocks of length n using a key of length m, to form ciphertext blocks of length n. A block cipher is said to satisfy the strict key avalanche criterion if a one bit change in the key causes on the average one half of the ciphertext bit positions to change. In this paper the importance of the strict key avala...

An earlier paper by the same author suggested combining a block cipher and a stream cipher to get a strong hybrid cipher. This paper proposes a specific cipher based on those ideas, using the HC-128 stream cipher and a tweakable block cipher based on Serpent. Table of

The idea of double block length hashing is to construct a compression function on 2n bits using a block cipher with an n-bit block size. All optimally secure double length hash functions known in the literature employ a cipher with a key space of double block size, 2n-bit. On the other hand, no optimally secure compression functions built from a cipher with an n-bit key space are known. Our wor...

In this paper, we propose a new lightweight block cipher named RECTANGLE. The main idea of the design of RECTANGLE is to allow lightweight and fast implementations using bit-slice techniques. RECTANGLE uses an SPnetwork. The substitution layer consists of 16 4×4 S-boxes in parallel. The permutation layer is composed of 3 rotations. As shown in this paper, RECTANGLE offers great performance in b...

Hidden vector encryption (HVE), introduced by Boneh and Waters in TCC’07, is an expressive sub-class of predicate encryption, that allows conjunctive, subset, range and comparison queries over encrypted data. All existing HVE constructions in the cryptographic literature use bilinear pairings over either composite order or prime order groups. In this paper, we address the open problem of constr...

For constrained devices, standard cryptographic algorithms can be too big, too slow or too energy-consuming. The area of lightweight cryptography studies new algorithms to overcome these problems. In this paper, we will focus on symmetric-key encryption, authentication and hashing. Instead of providing a full overview of this area of research, we will highlight three interesting topics. Firstly...

Given a block cipher of length L Cook’s elastic cipher allows to encrypt messages of variable length from L to 2L. Given some conditions on the key schedule, Cook’s elastic cipher is secure against any key recovery attack if the underlying block cipher is, and it achieves complete diffusion in at most q+1 rounds if the underlying block cipher achieves it in q rounds. We extend Cook’s constructi...