L'objectiu del grup de recerca és l'estudi dels problemes matemàtics de més actualitat en el camp de la criptologia. Els temes de recerca se centren principalment en els aspectes següents:
- Criptografia distribu´da. Les parts implicades en el protocol criptogràfic són col·lectius que hauran de compartir certa informació secreta.
En aquest punt cal destacar la computació multipart i els esquemes de distribució de secrets.
- Protocols criptogràfics segurs. En aquest punt es tracta d'analitzar i dissenyar protocols, tant de xifratge com de signatura digital, que siguin eficients i segurs. La definició de seguretat també és tema d'estudi.
Destaquem també l'estudi de les aplicacions de les corbes el·líptiques a la criptografia.

The main goal of the research group is the study of mathematical problems in cryptology.
The main research areas are the following:
- Distributed cryptography. The groups working on cryptographic protocols have to share secret information. Multi-party computation and secret-sharing schemes are also studied.
- Secure cryptographic protocols. The aim is to analyse and design efficient and secure protocols, both for encryption and for digital signatures.
The definition of security is also the subject of research. The applications of elliptic curves in cryptography are also studied.

The main goal of the research group is the study of mathematical problems in cryptology.
The main research areas are the following:
- Distributed cryptography. The groups working on cryptographic protocols have to share secret information. Multi-party computation and secret-sharing schemes are also studied.
- Secure cryptographic protocols. The aim is to analyse and design efficient and secure protocols, both for encryption and for digital signatures.
The definition of security is also the subject of research. The applications of elliptic curves in cryptography are also studied.

### Enviaments recents

• #### Soft and hard modelling methods for decovolution of mixtures of Raman spectra for pigment analysis: a qualitative and quantitative approach ﻿

(2000-01)
Article
Accés restringit per política de l'editorial
Raman spectroscopy provides a means for the detection and identification of pictorial materials on artworks. As a non-destructive, applicable in situ and non-ambiguous technique, it is one of the most preferred to analyse ...

(1996-01)
Article
Accés obert
• #### An algebraic framework for Diffie–Hellman assumptions ﻿

(2015-10-22)
Article
Accés restringit per política de l'editorial
We put forward a new algebraic framework to generalize and analyze Diffie-Hellman like Decisional Assumptions which allows us to argue about security and applications by considering only algebraic properties. Our D,k-MDDH ...
• #### Extending Brickell-Davenport theorem to non-perfect secret sharing schemes ﻿

(2015-02)
Article
Accés restringit per política de l'editorial
One important result in secret sharing is the Brickell-Davenport Theorem: every ideal perfect secret sharing scheme de nes a matroid that is uniquely determined by the access structure. Even though a few attempts have been ...
• #### On secret sharing with nonlinear product reconstruction ﻿

(2015-06-24)
Article
Accés restringit per política de l'editorial
Multiplicative linear secret sharing is a fundamental notion in the area of secure multi- party computation (MPC) and, since recently, in the area of two-party cryptography as well. In a nutshell, this notion guarantees ...
• #### Attribute-based versions of Schnorr and ElGamal ﻿

(2016-01)
Article
Accés obert
We design in this paper the first attribute-based cryptosystems that work in the classical discrete logarithm, pairing-free, setting. The attribute-based signature scheme can be seen as an extension of Schnorr signatures, ...
• #### Secret sharing, rank inequalities, and information inequalities ﻿

(2016-01)
Article
Accés obert
Beimel and Orlov proved that all information inequalities on four or five variables, together with all information inequalities on more than five variables that are known to date, provide lower bounds on the size of the ...
• #### Revisiting distance-based record linkage for privacy-preserving release of statistical datasets ﻿

(Elsevier, 2015-07-17)
Article
Accés restringit per política de l'editorial
Statistical Disclosure Control (SDC, for short) studies the problem of privacy-preserving data publishing in cases where the data is expected to be used for statistical analysis. An original dataset T containing sensitive ...
• #### Vote validatability in Mix-Net-based eVoting ﻿

(2015)
Article
Accés restringit per política de l'editorial
One way to build secure electronic voting systems is to use Mix-Nets, which break any correlation between voters and their votes. One of the characteristics of Mix-Net-based eVoting is that ballots are usually decrypted ...
• #### Matrix computational assumptions in multilinear groups ﻿

(2015-04-20)
Report de recerca
Accés obert
We put forward a new family of computational assumptions, the Kernel Matrix Di e- Hellman Assumption. Given some matrix A sampled from some distribution D ;k , the kernel as- sumption says that it is hard to nd \in the exponent