Generation of Efficient Key Bit-Streams Using Sparse Matrix-Vector Multiplication

Space Efficient Cryptographic Protocol Using Recursive Bitwise & Pairs Of Bits Of Operation (RBPBO)

The technique considers a message as binary string on which a Efficient Cryptographic Protocol using Recursive Bitwise amd pairs of Bits of operation (RBPBO) is performed. A block of n bits is taken as an input stream, where n varies from 4 to 256, from a continuous stream of bits and the technique operates on it to generate the intermediate encrypted stream. This technique directly involves all the bits of blocks in a boolean operation and a session key. The same operation is performed repeatedly for different block sizes as per the specification of a session key to generate the final encrypt…

Grain流密码族：抽象定义、组件强化与新型具体实例

The Grain Family of Stream Ciphers: an Abstraction, Strengthening of Components and New Concrete Instantiations

本文针对Grain流密码族给出形式化抽象定义，强化核心组件设计，提出覆盖80至256比特多安全级别的7个具体实例，在各安全级别下均实现了更优的密码学性质或更低的门电路开销。

COZMO-A New Lightweight Stream Cipher

This paper deals with the merger of the two lightweight stream ciphers: A5by1 and Trivium. The idea is to make the key stream generation more secure and to remove the attacks of the individual algorithms. The bits generated by the Trivium cipher will act as the input of the A5by1 cipher. The registers used in the A5by1 cipher will be filled by the output bits of the Trivium cipher. The three registers will then be connected to generate an output which will be our required key stream.

SOSEMANUK: a fast software-oriented stream cipher

Sosemanuk is a new synchronous software-oriented stream cipher, corresponding to Profile 1 of the ECRYPT call for stream cipher primitives. Its key length is variable between 128 and 256 bits. It ac- commodates a 128-bit initial value. Any key length is claimed to achieve 128-bit security. The Sosemanuk cipher uses both some basic design principles from the stream cipher SNOW 2.0 and some transformations derived from the block cipher SERPENT. Sosemanuk aims at improv- ing SNOW 2.0 both from the security and from the efficiency points of view. Most notably, it uses a faster IV-setup procedure. …

Fully Homomorphic Encryption based on Multivariate Polynomial Evaluation

We propose a multi-bit leveled fully homomorphic encryption scheme using multivariate polynomial evaluations. The security of the scheme depends on the hardness of the Learning with Errors (LWE) problem. For homomorphic multiplication, the scheme uses a polynomial based technique that does not require relinearization (and key switching). The noise associated with the ciphertext increases only linearly with every multiplication.

面向物联网的轻量级混合分组-流密码算法

Lightweight Hybrid Block-Stream Cryptographic Algorithm for the Internet of Things

提出面向物联网设备的轻量级混合加密算法 SEPAR，通过融合伪随机置换与生成函数提升安全性和速度，并在多平台验证其显著性能优势。

MOBS (Matrices Over Bit Strings) public key exchange

We use matrices over bit strings as platforms for Diffie-Hellman-like public key exchange protocols. When multiplying matrices like that, we use Boolean OR operation on bit strings in place of addition and Boolean AND operation in place of multiplication. As a result, (1) computations with these matrices are very efficient; (2) standard methods of attacking Diffie-Hellman-like protocols are not applicable.

GF(2m)上模乘器的FPGA高效硬件实现

Efficient Hardware Implementation of Modular Multiplier over GF (2m) on FPGA

本文提出一种结合传统乘法与Karatsuba乘法的混合模乘硬件实现，面向NIST B-163/233/283/571参数，在FPGA上显著降低LUT使用、提升延迟与面积-延迟积，优化ECC点乘效率。

Generalised Mersenne Numbers Revisited

Generalised Mersenne Numbers (GMNs) were defined by Solinas in 1999 and feature in the NIST (FIPS 186-2) and SECG standards for use in elliptic curve cryptography. Their form is such that modular reduction is extremely efficient, thus making them an attractive choice for modular multiplication implementation. However, the issue of residue multiplication efficiency seems to have been overlooked. Asymptotically, using a cyclic rather than a linear convolution, residue multiplication modulo a Mersenne number is twice as fast as integer multiplication; this property does not hold for prime GMNs, u…

Speeding Up Elliptic Curve Multiplication with Mixed-base Representation for Applications to SIDH Ciphers

Elliptic curve multiplications can be improved by replacing the standard ladder algorithm's base 2 representation of the scalar multiplicand, with mixed-base representations with power-of-2 bases, processing the n bits of the current digit in one optimized step. For this purpose, we also present a new methodology to compute, for Weierstrass form elliptic curves in the affine plane, operations of the type mP+nQ where m and n are small integers. This provides implementations with the lower cost than previous algorithms, using only one inversion. In particular, the proposed techniques enable more…

An algebraic attack to the Bluetooth stream cipher E0

In this paper we study the security of the Bluetooth stream cipher E0 from the viewpoint it is a "difference stream cipher", that is, it is defined by a system of explicit difference equations over the finite field GF(2). This approach highlights some issues of the Bluetooth encryption such as the invertibility of its state transition map, a special set of 14 bits of its 132-bit state which when guessed implies linear equations among the other bits and finally a small number of spurious keys, with 83 guessed bits, which are compatible with a keystream of about 60 bits. Exploiting these issues,…