Cryptanalysis of a key exchange scheme based on block matrices
نویسندگان
چکیده
In this paper we describe a cryptanalysis of a key exchange scheme recently proposed by Álvarez, Tortosa, Vicent and Zamora. The scheme is based on exponentiation of block matrices over a finite field of prime order. We present an efficient reduction of the problem of disclosing the shared key to the discrete logarithm problem (DLP) in an extension of the base field.
منابع مشابه
An efficient secure channel coding scheme based on polar codes
In this paper, we propose a new framework for joint encryption encoding scheme based on polar codes, namely efficient and secure joint secret key encryption channel coding scheme. The issue of using new coding structure, i.e. polar codes in Rao-Nam (RN) like schemes is addressed. Cryptanalysis methods show that the proposed scheme has an acceptable level of security with a relatively smaller ke...
متن کاملImpossible Differential Cryptanalysis on Deoxys-BC-256
Deoxys is a final-round candidate of the CAESAR competition. Deoxys is built upon an internal tweakable block cipher Deoxys-BC, where in addition to the plaintext and key, it takes an extra non-secret input called a tweak. This paper presents the first impossible differential cryptanalysis of Deoxys-BC-256 which is used in Deoxys as an internal tweakable block cipher. First, we find a 4.5-round...
متن کاملImpossible Differential Cryptanalysis of Reduced-Round Midori64 Block Cipher (Extended Version)
Impossible differential attack is a well-known mean to examine robustness of block ciphers. Using impossible differ- ential cryptanalysis, we analyze security of a family of lightweight block ciphers, named Midori, that are designed considering low energy consumption. Midori state size can be either 64 bits for Midori64 or 128 bits for Midori128; however, both vers...
متن کاملCryptanalysis of Álvarez et al. key exchange scheme
Álvarez et al. (Information Sciences, Vol. 179, Issue 12, 2009) proposed a new key exchange scheme where the secret key is obtained by multiplying powers of block upper triangular matrices whose elements are defined over Zp. In this note, we show that breaking this system with security parameters (r, s, p) is equivalent to solving a set of 3(r + s) linear equations with 2(r+s) unknowns in Zp, w...
متن کاملA new method for accelerating impossible differential cryptanalysis and its application on LBlock
Impossible differential cryptanalysis, the extension of differential cryptanalysis, is one of the most efficient attacks against block ciphers. This cryptanalysis method has been applied to most of the block ciphers and has shown significant results. Using structures, key schedule considerations, early abort, and pre-computation are some common methods to reduce complexities of this attack. In ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Inf. Sci.
دوره 276 شماره
صفحات -
تاریخ انتشار 2009