Publication

On some weak extensions of AES and BES

Serge Vaudenay
2004
Conference Papers

Abstract

In 2002, Murphy and Robshaw introduced an extension BES of AES and argued this could compromise the security of AES. We introduce here two block-ciphers CES and big-BES that are some extensions of the AES and BES respectively in the spirit of Hensel lifting extensions. They are defined similarly to the AES respectively BES except that every operations are performed in a ring structure including the field GF(28). We show that the AES and BES can be embedded in their extensions. More precisely, by restricting these extensions on a given subset, we obtain a fully equivalent description of the AES and BES. Furthermore, we show that these natural extensions are trivially weak by describing a cryptanalysis of them despite it leads to no consequence about the security of AES or BES. This shows that (except the nice mathematical construction) the Murphy-Robshaw extension might be pointless

Official source

https://infoscience.epfl.ch/entities/publication/8e02c976-3599-4ef9-90b3-bd207ca81a58

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Serge Vaudenay
2004
Conference Papers

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/8e02c976-3599-4ef9-90b3-bd207ca81a58

About this result

Related concepts (32)

Finite field

In mathematics, a finite field or Galois field (so-named in honor of Évariste Galois) is a field that contains a finite number of elements. As with any field, a finite field is a set on which the operations of multiplication, addition, subtraction and division are defined and satisfy certain basic rules. The most common examples of finite fields are given by the integers mod p when p is a prime number. The order of a finite field is its number of elements, which is either a prime number or a prime power.

Cryptanalysis

Cryptanalysis (from the Greek kryptós, "hidden", and analýein, "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown. In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation.

Separable extension

In field theory, a branch of algebra, an algebraic field extension is called a separable extension if for every , the minimal polynomial of over F is a separable polynomial (i.e., its formal derivative is not the zero polynomial, or equivalently it has no repeated roots in any extension field). There is also a more general definition that applies when E is not necessarily algebraic over F. An extension that is not separable is said to be inseparable.

Related publications (14)

On some weak extensions of AES and BES

Chat with Graph Search

System Software Design for Undiluted Attestation

On the security of two blind signatures from code equivalence problems

Numerical back-analysis & future risk assessment of the Hirschigraben landslide(s)