14,230 research outputs found
Systematization of a 256-bit lightweight block cipher Marvin
In a world heavily loaded by information, there is a great need for keeping
specific information secure from adversaries. The rapid growth in the research
field of lightweight cryptography can be seen from the list of the number of
lightweight stream as well as block ciphers that has been proposed in the
recent years. This paper focuses only on the subject of lightweight block
ciphers. In this paper, we have proposed a new 256 bit lightweight block cipher
named as Marvin, that belongs to the family of Extended LS designs.Comment: 12 pages,6 figure
Dynamic MDS Matrices for Substantial Cryptographic Strength
Ciphers get their strength from the mathematical functions of confusion and
diffusion, also known as substitution and permutation. These were the basics of
classical cryptography and they are still the basic part of modern ciphers. In
block ciphers diffusion is achieved by the use of Maximum Distance Separable
(MDS) matrices. In this paper we present some methods for constructing dynamic
(and random) MDS matrices.Comment: Short paper at WISA'10, 201
Symmetric block ciphers with a block length of 32 bit
Subject of the thesis at hand is the analysis of symmetric block ciphers with a block length of 32 bit. It is meant to give a comprising overview over the topic of 32 bit block ciphers. The topic is divided in the examination of three questions. It contains a list of state of the art block ciphers with a block length of 32 bit. The block ciphers are being described, focussing on the encryption function. An SPN-based cipher with 32 bit block length is being proposed by rescaling the AES cipher.
The 32 bit block length results in certain security issues. These so called risk factors are analysed and mitigating measures are proposed. The result of the thesis is, that 32 bit block ciphers can be implemented in a secure manner. The use of 32 bit ciphers should be limited to specific use-cases and with a profound risk analysis, to determine the protection class of the data to be encrypted
Notions and relations for RKA-secure permutation and function families
The theory of designing block ciphers is mature, having seen signi¯cant
progress since the early 1990s for over two decades, especially during the AES devel-
opment e®ort. Nevertheless, interesting directions exist, in particular in the study of
the provable security of block ciphers along similar veins as public-key primitives, i.e.
the notion of pseudorandomness (PRP) and indistinguishability (IND). Furthermore,
recent cryptanalytic progress has shown that block ciphers well designed against known
cryptanalysis techniques including related-key attacks (RKA) may turn out to be less
secure against related-key attacks than expected. The notion of provable security of
block ciphers against related-key attacks was initiated by Bellare and Kohno, and sub-
sequently treated by Lucks. Concrete block cipher constructions were proposed therein
with provable security guarantees. In this paper, we are interested in the security no-
tions for RKA-secure block ciphers
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