Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.
AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.
It is a well known fact that encryption schemes can not hide a plaintext length when it is unbounded. We thus admit that an approximation of it may leak and we focus on hiding its precise value. Some standards such as TLS or SSH offer to do it by applying ...
Asynchronous task allocation is a fundamental problem in distributed computing in which p asynchronous processes must execute a set of m tasks. Also known as write-all or do-all, this problem been studied extensively, both independently and as a key buildi ...
We give two new randomized algorithms for tight renaming, both of which work against an adaptive adversary. The first uses repeated sampling over a sequence of arrays of decreasing size to assign unique names to each of n processes with step complexity $ ...
Acm Order Department, P O Box 64145, Baltimore, Md 21264 Usa2011
We consider several "provably secure" hash functions that compute simple sums in a well chosen group (G,*). Security properties of such functions provably translate in a natural way to computational problems in G that are simple to define and possibly also ...
EPFL2011
, ,
We study a new application of threshold-based secret sharing in a distributed online social network (DOSN), where users need a means to back up and recover their private keys in a network of untrusted servers. Using a simple threshold-based secret sharing ...
Ieee Computer Soc Press, Customer Service Center, Po Box 3014, 10662 Los Vaqueros Circle, Los Alamitos, Ca 90720-1264 Usa2009
,
In this paper, we study the complexity of gossip in an asynchronous, message-passing fault-prone distributed system. In short, we show that an adaptive adversary can significantly hamper the spreading of a rumor, while an oblivious adversary cannot. In the ...
2008
Recently, two e-mail protocols were proposed claiming to provide perfect secrecy. These protocols use authentication and (Diffie-Hellman) key-exchange techniques, and as such, other standard security criteria besides perfect forward secrecy include key-rep ...
2008
We introduce C, a practical provably secure block cipher with a slow key schedule. C is based on the same structure as AES but uses independent random substitution boxes instead of a fixed one. Its key schedule is based on the Blum-Blum-Shub pseudo-random ...
Springer2007
In this paper, we describe a sequence of simple, yet e cient chosen-plaintext (or chosen-ciphertext) attacks against reduced-round versions of IDEA (with 2, 2.5, 3, 3.5, and 4 rounds) which compare favourably with the best known attacks: some of them decre ...
2005
In this article we offer guidelines for the determination of key sizes for symmetric cryptosystems, RSA, and discrete logarithm-based cryptosystems both over finite fields and over groups of elliptic curves over prime fields. Our recommendations are based ...
