5.4. Parallel-CFS
- document 1 document 2 document 3
- niveau 1 niveau 2 niveau 3
- audio 1 audio 2 audio 3
Descriptif
In this session, I willpresent a variant of the CFS signature scheme calledparallel-CFS. We start from a simple question: whathappens if you try to use two different hash functions andcompute two different CFS signatures? For the signer, you simplytake twice as much computation because you have todo two signatures. And then, the signature istwice longer because you have just to concatenate two signatures. One would assume that forthe attacker it is the same, he simply has to forge two signatures. Well, things are a littlemore complicated than that. What happens when you want to dodecoding one out of many twice in a row? So, you start with a set ofN documents and compute the hashes of these documents tobuild a list of target syndromes. As we have seen, if N =2^(mt/3), one solution is found on average. Then, we canmove on to the second hash function and try to doalso decoding one out of many. The only problem is, youonly have one solution with the first hash function. So,you only have one target document for the secondproblem and you cannot do decoding one out of many anymore. In order to be able to do decoding one out of manytwice in a row, you need to start from a muchlarger list of syndromes. Then, find a set ofsolutions instead of just a single solution and use this setof solutions to find one solution to both hashfunctions at the time. This means that the set oftarget syndromes has to be larger and the complexityof the attack will be larger. We have just seen thatfor the attacker, computing syndrome decoding twice ina row is more complicated. But the same kind ofproblem happens to the legitimate signer when using counters.The first strategy would be first, pick a document D,use the first hash function to compute a signature, thiswill get the value of the counter i; then, use h' tocompute the second signature with a second valueof the counter i'.
Intervenant
Thème
Notice
Documentation
Dans la même collection
-
5.7. The Fast Syndrome-Based (FSB) Hash FunctionMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In the last session of this week, we will have a look at the FSB Hash Function which is built using the one-way function we saw in the previous session. What are the requirements for a
-
5.5. Stern’s Zero-Knowledge Identification SchemeMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we are going to have a look at Stern’s Zero-Knowledge Identification Scheme. So, what is a Zero-Knowledge Identification Scheme? An identification scheme allows a prover to prove
-
5.6. An Efficient Provably Secure One-Way FunctionMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we are going to see how to build an efficient provably secure one-way function from coding theory. As you know, a one-way function is a function which is simple to evaluate and
-
5.3. Attacks against the CFS SchemeMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we will have a look at the attacks against the CFS signature scheme. As for public-key encryption, there are two kinds of attacks against signature schemes. First kind of attack is
-
5.1. Code-Based Digital SignaturesMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
Welcome to the last week of this MOOC on code-based cryptography. This week, we will be discussing other cryptographic constructions relying on coding theory. We have seen how to do public key
-
5.2. The Courtois-Finiasz-Sendrier (CFS) ConstructionMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, I am going to present the Courtois-Finiasz-Sendrier Construction of a code-based digital signature. In the previous session, we have seen that it is impossible to hash a document
Avec les mêmes intervenants
-
5.7. The Fast Syndrome-Based (FSB) Hash FunctionMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In the last session of this week, we will have a look at the FSB Hash Function which is built using the one-way function we saw in the previous session. What are the requirements for a
-
5.5. Stern’s Zero-Knowledge Identification SchemeMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we are going to have a look at Stern’s Zero-Knowledge Identification Scheme. So, what is a Zero-Knowledge Identification Scheme? An identification scheme allows a prover to prove
-
5.6. An Efficient Provably Secure One-Way FunctionMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we are going to see how to build an efficient provably secure one-way function from coding theory. As you know, a one-way function is a function which is simple to evaluate and
-
5.3. Attacks against the CFS SchemeMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we will have a look at the attacks against the CFS signature scheme. As for public-key encryption, there are two kinds of attacks against signature schemes. First kind of attack is
-
5.1. Code-Based Digital SignaturesMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
Welcome to the last week of this MOOC on code-based cryptography. This week, we will be discussing other cryptographic constructions relying on coding theory. We have seen how to do public key
-
5.2. The Courtois-Finiasz-Sendrier (CFS) ConstructionMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, I am going to present the Courtois-Finiasz-Sendrier Construction of a code-based digital signature. In the previous session, we have seen that it is impossible to hash a document
-
4.8. Attack against Algebraic Geometry codesMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we will present an attack against Algebraic Geometry codes (AG codes). Algebraic Geometry codes is determined by a triple. First of all, an algebraic curve of genus g, then a n
-
4.9. Goppa codes still resistMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
All the results that we have seen this week doesn't mean that code based cryptography is broken. So in this session we will see that Goppa code still resists to all these attacks. So recall that
-
4.7. Attack against Reed-Muller codesMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we will introduce an attack against binary Reed-Muller codes. Reed-Muller codes were introduced by Muller in 1954 and, later, Reed provided the first efficient decoding algorithm
-
4.5. Error-Correcting PairsMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
We present in this session a general decoding method for linear codes. And we will see it in an example. Let C be a generalized Reed-Solomon code of dimension k associated to the pair (c, d). Then,
-
4.6. Attack against GRS codesMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session we will discuss the proposal of using generalized Reed-Solomon codes for the McEliece cryptosystem. As we have already said, generalized Reed-Solomon codes were proposed in 1986 by
-
4.4. Attack against subcodes of GRS codesMarquez-CorbellaIreneSendrierNicolasFiniaszMatthieu
In this session, we will talk about using subcodes of a Generalized Reed–Solomon code for the McEliece Cryptosystem. Recall that to avoid the attack of Sidelnikov and Shestakov, Berger and
Sur le même thème
-
Inauguration de l'exposition - Vanessa Vitse : Nombres de Sophie Germain et codes secretsVitseVanessa
Exposé de Vanessa Vitse (Institut Fourier) : Nombres de Sophie Germain et codes secrets
-
"Le mathématicien Petre (Pierre) Sergescu, historien des sciences, personnalité du XXe siècle"HerléaAlexandre
Alexandre HERLEA est membre de la section « Sciences, histoire des sciences et des techniques et archéologie industrielle » du CTHS. Professeur émérite des universités, membre effectif de l'Académie
-
Retour d'expérience sur l'utilisation croisée de plusieurs archives de fouillesTufféryChristophe
Dans le cadre d'une thèse de doctorat engagée depuis 2019, une étude historiographique et épistémologique des effets des dispositifs numériques sur l'archéologie et sur les archéologues au cours des
-
Information Structures for Privacy and FairnessPalamidessiCatuscia
Information Structures for Privacy and Fairness
-
Le Creativ’Lab, au cœur de la robotique et de l’intelligence artificielle (ASR N°18 - LORIA)HénaffPatrickLefebvreSylvain
Le LORIA, laboratoire phare de la Grande Région dans le domaine de l’informatique, propose de rendre la recherche plus ouverte, plus collaborative, plus ambitieuse… en un mot, plus créative, à travers
-
AI and Human Decision-Making: An Interdisciplinary PerspectiveCastellucciaClaude
This seminar will talk about some of the privacy risks of these systems and will describe some recent attacks. It will also discuss why they sometimes fail to deliver. Finally, we will also show that
-
Webinaire sur la rédaction des PGDLouvetViolaine
Rédaction des Plans de Gestion de Données (PGD) sous l’angle des besoins de la communauté mathématique.
-
Les algorithmes de Parcoursup
L’objectif de la journée « Algorithmes d’aide à la décision publique » était de sensibiliser le grand public aux rôles des algorithmes d’aide à la décision publique utilisés par exemple pour l
-
Algorithmes d'aide à la décision publique / Ouverture
L’objectif de la journée « Algorithmes d’aide à la décision publique » était de sensibiliser le grand public aux rôles des algorithmes d’aide à la décision publique utilisés par exemple pour l
-
Quelques enjeux autour des algorithmes d'aide à la décision publique
L’objectif de la journée « Algorithmes d’aide à la décision publique » était de sensibiliser le grand public aux rôles des algorithmes d’aide à la décision publique utilisés par exemple pour l
-
Un nouveau système de répartition des greffons cardiaques utilisant un algorithme
L’objectif de la journée « Algorithmes d’aide à la décision publique » était de sensibiliser le grand public aux rôles des algorithmes d’aide à la décision publique utilisés par exemple pour l
-
Règles, calcul et politique : investigation des choix de programmation inaperçus pour les aides au …
L’objectif de la journée « Algorithmes d’aide à la décision publique » était de sensibiliser le grand public aux rôles des algorithmes d’aide à la décision publique utilisés par exemple pour l
