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  • Contributions to Secret Sharing and Other Distributed Cryptosystems  Open access

     Ruiz Rodriguez, Alexandre
    Defense's date: 2013-07-22
    Universitat Politècnica de Catalunya
    Theses

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    The present thesis deals with primitives related to the eld of distributed cryptography. First, we study signcryption schemes, which provide at the same time the functionalities of encryption and signature, where the unsigncryption operation is distributed. We consider this primitive from a theoretical point of view and set a security framework for it. Then, we present two signcryption schemes with threshold unsigncryption, with di erent properties. Furthermore, we use their authenticity property to apply them in the development of a di erent primitive: digital signatures with distributed veri cation. The second block of the thesis deals with the primitive of multi-secret sharing schemes. After stating some e ciency limitations of multi-secret sharing schemes in an information-theoretic scenario, we present several multi-secret sharing schemes with provable computational security. Finally, we use the results in multi-secret sharing schemes to generalize the traditional framework of distributed cryptography (with a single policy of authorized subsets) into a multipolicy setting, and we present both a multi-policy distributed decryption scheme and a multi-policy distributed signature scheme. Additionally, we give a short outlook on how to apply the presented multi-secret sharing schemes in the design of other multi-policy cryptosystems, like the signcryption schemes considered in this thesis. For all the schemes proposed throughout the thesis, we follow the same formal structure. After de ning the protocols of the primitive and the corresponding security model, we propose the new scheme and formally prove its security, by showing a reduction to some computationally hard mathematical problem.

    Avui en dia les persones estan implicades cada dia més en diferents activitats digitals tant en la seva vida professional com en el seu temps lliure. Molts articles de paper, com diners i tiquets, estan sent reemplaçats més i més per objectes digitals. La criptografia juga un paper crucial en aquesta transformació, perquè proporciona seguretat en la comunicació entre els diferents participants que utilitzen un canal digital. Depenent de la situació específica, alguns requisits de seguretat en la comunicació poden incloure privacitat (o confidencialitat), autenticitat, integritat o no-repudi. En algunes situacions, repartir l'operació secreta entre un grup de participants fa el procés més segur i fiable que quan la informació secreta està centralitzada en un únic participant; la criptografia distribuïda és l’àrea de la criptografia que estudia aquestes situacions. Aquesta tesi tracta de primitives relacionades amb el camp de la criptografia distribuïda. Primer, estudiem esquemes “signcryption”, que ofereixen a la vegada les funcionalitats de xifrat i signatura, on l'operació de “unsigncryption” està distribuïda. Considerem aquesta primitiva des d’un punt de vista teòric i establim un marc de seguretat per ella. Llavors, presentem dos esquemes “signcryption” amb operació de “unsigncryption” determinada per una estructura llindar, cada un amb diferents propietats. A més, utilitzem la seva propietat d’autenticitat per desenvolupar una nova primitiva: signatures digitals amb verificació distribuïda. El segon bloc de la tesi tracta la primitiva dels esquemes de compartició de multi-secrets. Després de demostrar algunes limitacions en l’eficiència dels esquemes de compartició de multi-secrets en un escenari de teoria de la informació, presentem diversos esquemes de compartició de multi-secrets amb seguretat computacional demostrable. Finalment, utilitzem els resultats obtinguts en els esquemes de compartició de multi-secrets per generalitzar el paradigma tradicional de la criptografia distribuïda (amb una única política de subconjunts autoritzats) a un marc multi-política, i presentem un esquema de desxifrat distribuït amb multi-política i un esquema de signatura distribuïda amb multi-política. A més, donem indicacions de com es poden aplicar els nostres esquemes de compartició de multi-secrets en el disseny d’altres criptosistemes amb multi-política, com per exemple els esquemes “signcryption” considerats en aquesta tesi. Per tots els esquemes proposats al llarg d’aquesta tesi, seguim la mateixa estructura formal. Després de definir els protocols de la primitiva primitius i el model de seguretat corresponent, proposem el nou esquema i demostrem formalment la seva seguretat, mitjançant una reducció a algun problema matemàtic computacionalment difícil.

  • Identity-based encryption with master key-dependent message security and leakage-resilience

     Galindo, David; Herranz Sotoca, Javier; Villar Santos, Jorge Luis
    European Symposium on Research in Computer Security
    Presentation's date: 2012-09
    Presentation of work at congresses

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    Cifrado homomorfico de clave publica basado en Residuosidad Cuadratica  Open access

     Herranz Sotoca, Javier; Sisternes, Juan Ramón
    Reunión Española sobre Criptología y Seguridad de la Información
    Presentation's date: 2012-09
    Presentation of work at congresses

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    Los esquemas de cifrado de clave p´ ublica con propiedades homom´orficas tienen muchas utilidades en aplicaciones reales. Entre los esquemas con propiedades homom´orficas aditivas existentes, hay una familia (desde el esquema de Goldwasser-Micali hasta el esquema de Paillier) cuya seguridad se basa en problemas computacionalmente dif´ıciles relacionados con el problema de factorizar un n´umero grande N. Los esquemas de esta familia tienen diferentes propiedades tanto en lo referente a la eficiencia, como al problema de teor´ıa de n´umeros concreto en el que basan su seguridad. En este art´ıculo proponemos un nuevo esquema a a˜nadir a esta familia. La hip´otesis computacional en la que se basa la seguridad de nuestro esquema es la hip´otesis de la Residuosidad Cuadr´atica m´odulo N. En t´erminos de eficiencia, por un lado nuestro esquema mejora todos los esquemas anteriores cuya seguridad se basa en la hip´otesis de la Residuosidad d-´esima m´odulo N, para d 2; por otro lado, nuestro esquema es en general menos eficiente (tiempo de descifrado) que algunos esquemas como el de Paillier, cuya seguridad se basa en otra hip´otesis (Residuosidad N-´esima m´odulo N2). Sin embargo, si los mensajes a cifrar son cortos, la eficiencia de nuestro esquema es esencialmente la misma que la del esquema de Paillier

  • Short attribute-based signatures for threshold predicates

     Herranz Sotoca, Javier; Laguillaumie, Fabien; Libert, B.; Rafols Salvador, Carla
    Cryptographers' Track at the RSA Conference
    Presentation's date: 2012
    Presentation of work at congresses

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    Firmas digitales con verificación distribuida en el modelo de seguridad estándar  Open access

     Herranz Sotoca, Javier; Ruiz Rodriguez, Alexandre; Saez Moreno, German
    Reunión Española sobre Criptología y Seguridad de la Información
    Presentation's date: 2012-09
    Presentation of work at congresses

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    Las firmas digitales con verificaci´on distribuida protegen en cierta manera el nivel de anonimato o privacidad del firmante, ya que un subconjunto autorizado de usuarios deben colaboran para verificar la (in)validez de una firma. En trabajos anteriores se propusieron esquemas de este tipo pero que o no alcanzaban el nivel m´aximo de seguridad o bien lo hac´ıan en el modelo del or´aculo aleatorio. Proponemos aqu´ı el primer esquema de firma digital con verificaci´on distribuida que consigue seguridad m´axima, en t´erminos de infalsificabilidad y privacidad, y con seguridad demostrable en el modelo de computaci´on est´andar.

  • Foreword from the DPM 2012 program chairs

     Di Pietro, Roberto; Herranz Sotoca, Javier
    Lecture notes in computer science
    Date of publication: 2012-09-13
    Journal article

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  • Kd-trees and the real disclosure risks of large statistical databases

     Herranz Sotoca, Javier; Nin Guerrero, Jordi; Solé Simó, Marc
    Information fusion
    Date of publication: 2012
    Journal article

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    In data privacy, record linkage can be used as an estimator of the disclosure risk of protected data. To model the worst case scenario one normally attempts to link records from the original data to the protected data. In this paper we introduce a parametrization of record linkage in terms of a weighted mean and its weights, and provide a supervised learning method to determine the optimum weights for the linkage process. That is, the parameters yielding a maximal record linkage between the protected and original data. We compare our method to standard record linkage with data from several protection methods widely used in statistical disclosure control, and study the results taking into account the performance in the linkage process, and its computational effort

  • More hybrid and secure protection of statistical data sets

     Herranz Sotoca, Javier; Nin Guerrero, Jordi; Solé Simó, Marc
    IEEE transactions on dependable and secure computing
    Date of publication: 2012-09
    Journal article

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    Different methods and paradigms to protect data sets containing sensitive statistical information have been proposed and studied. The idea is to publish a perturbed version of the data set that does not leak confidential information, but that still allows users to obtain meaningful statistical values about the original data. The two main paradigms for data set protection are the classical one and the synthetic one. Recently, the possibility of combining the two paradigms, leading to a hybrid paradigm, has been considered. In this work, we first analyze the security of some synthetic and (partially) hybrid methods that have been proposed in the last years, and we conclude that they suffer from a high interval disclosure risk. We then propose the first fully hybrid SDC methods; unfortunately, they also suffer from a quite high interval disclosure risk. To mitigate this, we propose a postprocessing technique that can be applied to any data set protected with a synthetic method, with the goal of reducing its interval disclosure risk. We describe through the paper a set of experiments performed on reference data sets that support our claims

  • Attribute-based encryption schemes with constant-size ciphertexts

     Attrapadung, Nuttapong; Herranz Sotoca, Javier; Laguillaumie, Fabien; Libert, B.; de Panafieu, Elie; Rafols Salvador, Carla
    Theoretical computer science
    Date of publication: 2012-03-09
    Journal article

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  • Revocable attribute-based signatures with adaptive security in the standard model

     Escala Ribas, Alex; Herranz Sotoca, Javier; Morillo Bosch, Maria Paz
    International Conference on Cryptology in Africa
    Presentation's date: 2011-07-05
    Presentation of work at congresses

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  • Relations between semantic security and anonymity in identity based encryption

     Herranz Sotoca, Javier; Laguillaumie, Fabien; Rafols Salvador, Carla
    Information processing letters
    Date of publication: 2011
    Journal article

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  • Attribute-based signature with policy-and-endorsement mechanism

     Herranz Sotoca, Javier
    Mathematical reviews
    Date of publication: 2011
    Journal article

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  • Restricted adaptive oblivious transfer

     Herranz Sotoca, Javier
    Theoretical computer science
    Date of publication: 2011-10-28
    Journal article

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  • Privacy-Providing Signatures and Their Applications

     Heidarvand, Somayed
    Defense's date: 2011-03-16
    Department of Applied Mathematics IV, Universitat Politècnica de Catalunya
    Theses

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    Optimal symbol alignment distance: a new distance for sequences of symbols  Open access

     Herranz Sotoca, Javier; Nin Guerrero, Jordi; Solé Simó, Marc
    IEEE transactions on knowledge and data engineering
    Date of publication: 2011-10-14
    Journal article

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    Comparison functions for sequences (of symbols) are important components of many applications, for example clustering, data cleansing and integration. For years, many efforts have been made to improve the performance of such comparison functions. Improvements have been done either at the cost of reducing the accuracy of the comparison, or by compromising certain basic characteristics of the functions, such as the triangular inequality. In this paper, we propose a new distance for sequences of symbols (or strings) called Optimal Symbol Alignment distance (OSA distance, for short). This distance has a very low cost in practice, which makes it a suitable candidate for computing distances in applications with large amounts of (very long) sequences. After providing a mathematical proof that the OSA distance is a real distance, we present some experiments for different scenarios (DNA sequences, record linkage, ...), showing that the proposed distance outperforms, in terms of execution time and/or accuracy, other well-known comparison functions such as the Edit or Jaro-Winkler distances.

    Postprint (author’s final draft)

  • Any 2-asummable bipartite function is weighted threshold

     Herranz Sotoca, Javier
    Discrete applied mathematics
    Date of publication: 2011-07-06
    Journal article

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  • Revocable attribute-based signatures with adaptive security in the standard model

     Escala Ribas, Alex; Herranz Sotoca, Javier; Morillo Bosch, Maria Paz
    Lecture notes in computer science
    Date of publication: 2011-05-10
    Journal article

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  • Attribute-based group key establishment

     Herranz Sotoca, Javier
    Mathematical reviews
    Date of publication: 2011
    Journal article

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  • New approaches for deniable authentication

     Herranz Sotoca, Javier
    Mathematical reviews
    Date of publication: 2011
    Journal article

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  • Constant size ciphertexts in threshold attribute-based encryption

     Herranz Sotoca, Javier; Laguillaumie, Fabien; Rafols Salvador, Carla
    International Conference on Practice and Theory in Public Key Cryptography
    Presentation's date: 2010-05-26
    Presentation of work at congresses

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  • Fully secure threshold unsigncryption

     Herranz Sotoca, Javier; Saez Moreno, German
    International Conference on Provable Security
    Presentation's date: 2010-10-14
    Presentation of work at congresses

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    Máxima seguridad para firmas digitales con verificación distribuida  Open access

     Herranz Sotoca, Javier; Ruiz Rodriguez, Alexandre; Saez Moreno, German
    Reunión Española sobre Criptología y Seguridad de la Información
    Presentation's date: 2010-09-10
    Presentation of work at congresses

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    Una de las opciones para proteger el nivel de anonimato o privacidad de un firmante es construir firmas digitales con verificación distribuida: se requiere la colaboración de un subconjunto autorizado de usuarios para verificar la (in)validez de una firma. En RECSI’08, se propuso un esquema de este tipo, pero que no alcanzaba el máximo nivel de seguridad. En este trabajo proponemos el primer esquema de firma digital con verificación distribuida que consigue seguridad máxima, en términos de infalsificabilidad y privacidad. Demostramos formalmente estas dos propiedades por reducción a problemas computacionales estándar, en el modelo del oráculo aleatorio.

    Postprint (author’s final draft)

  • Using classification methods to evaluate attribute disclosure risk

     Nin Guerrero, Jordi; Herranz Sotoca, Javier; Torra Raventós, Vicenç
    International Conference on Modeling Decisions for Artificial Intelligence
    Presentation's date: 2010-10-29
    Presentation of work at congresses

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  • Additively homomorphic encryption with d-operand multiplications

     Aguilar Melchor, Carlos; Gaborit, Philippe; Herranz Sotoca, Javier
    Lecture notes in computer science
    Date of publication: 2010
    Journal article

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  • Some (in)sufficient conditions for secure hybrid encryption

     Herranz Sotoca, Javier; Hofheinz, Dennis; Kiltz, Eike
    Information and computation
    Date of publication: 2010
    Journal article

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  • Introduction to privacy and anonymity in information management systems

     Herranz Sotoca, Javier; Nin Guerrero, Jordi
    Date of publication: 2010-07-29
    Book chapter

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  • CRIPTOGRAFIA DE CLAVE PUBLICA Y COMPARTICIÓN DE SECRETOS

     Morillo Bosch, Maria Paz; Gracia Rivas, Ignacio; Martí Farré, Jaume; Martin Mollevi, Sebastia; Padro Laimon, Carles; Saez Moreno, German; Herranz Sotoca, Javier; Rafols Salvador, Carla; Heidarvand, Somayed; Villar Santos, Jorge Luis
    Participation in a competitive project

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  • European Network of Excellence for Cryptology II

     Morillo Bosch, Maria Paz; Martí Farré, Jaume; Heidarvand, Somayed; Gracia Rivas, Ignacio; Padro Laimon, Carles; Martin Mollevi, Sebastia; Saez Moreno, German; Herranz Sotoca, Javier; Rafols Salvador, Carla; Villar Santos, Jorge Luis
    Participation in a competitive project

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  • Fully secure threshold unsigncryption

     Herranz Sotoca, Javier; Saez Moreno, German
    Lecture notes in computer science
    Date of publication: 2010-10-13
    Journal article

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  • Constant size ciphertexts in threshold attribute-based encryption

     Herranz Sotoca, Javier; Laguillaumie, Fabien; Rafols Salvador, Carla
    Lecture notes in computer science
    Date of publication: 2010
    Journal article

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  • On server trust in private proxy auctions

     Di Crescenzo, Giovanni; Herranz Sotoca, Javier; Saez Moreno, German
    Electronic commerce research
    Date of publication: 2010-10-09
    Journal article

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    We investigate proxy auctions, an auction model which is proving very successful for on-line businesses (e.g.http://www.ebay.com), where a trusted server manages bids from clients by continuously updating the current price of the item and the currently winning bid as well as keeping private the winning client’s maximum bid. We propose techniques for reducing the trust in the server by defining and achieving a security property, called server integrity. Informally, this property protects clients from a novel and large class of attacks from a corrupted server by allowing them to verify the correctness of updates to the current price and the currently winning bid. Our new auction scheme achieves server integrity and satisfies two important properties that are not enjoyed by previous work in the literature: it has minimal interaction, and only requires a single trusted server. The main ingredients of our scheme are two minimal-round implementations of zero-knowledge proofs for proving lower bounds on encrypted values: one based on discrete logarithms that is more efficient but uses the random oracle assumption, and another based on quadratic residuosity that only uses standard intractability assumptions but is less efficient.

  • Distributed privacy-preserving methods for statistical disclosure control

     Herranz Sotoca, Javier; Nin Guerrero, Jordi; Torra Raventós, Vicenç
    Lecture notes in computer science
    Date of publication: 2010
    Journal article

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    Statistical disclosure control (SDC) methods aim to protect privacy of the confidential information included in some databases, for example by perturbing the non-confidential parts of the original databases. Such methods are commonly used by statistical agencies before publishing the perturbed data, which must ensure privacy at the same time as it preserves as much as possible the statistical information of the original data. In this paper we consider the problem of designing distributed privacy-preserving versions of these perturbation methods: each part of the original database is owned by a different entity, and they want to jointly compute the perturbed version of the global database, without leaking any sensitive information on their individual parts of the original data. We show that some perturbation methods do not allow a private distributed extension, whereas other methods do. Among the methods that allow a distributed privacy-preserving version, we can list noise addition, resampling and a new protection method, rank shuffling, which is described and analyzed here for the first time.

  • Extensions of access structures and their cryptographic applications

     Daza Fernandez, Vanesa; Herranz Sotoca, Javier; Morillo Bosch, Maria Paz; Rafols Salvador, Carla
    Applicable algebra in engineering communication and computing
    Date of publication: 2010-07
    Journal article

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    Classifying data from protected statistical datasets  Open access

     Herranz Sotoca, Javier; Matwin, Stan; Nin Guerrero, Jordi; Torra Raventós, Vicenç
    Computers and security
    Date of publication: 2010-06-09
    Journal article

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    Statistical Disclosure Control (SDC) is an active research area in the recent years. The goal is to transform an original dataset X into a protected one X0, such that X0 does not reveal any relation between confidential and (quasi-)identifier attributes and such that X0 can be used to compute reliable statistical information about X. Many specific protection methods have been proposed and analyzed, with respect to the levels of privacy and utility that they offer. However, when measuring utility, only differences between the statistical values of X and X0 are considered. This would indicate that datasets protected by SDC methods can be used only for statistical purposes. We show in this paper that this is not the case, because a protected dataset X0 can be used to construct good classifiers for future data. To do so, we describe an extensive set of experiments that we have run with different SDC protection methods and different (real) datasets. In general, the resulting classifiers are very good, which is good news for both the SDC and the Privacy-preserving Data Mining communities. In particular, our results question the necessity of some specific protection methods that have appeared in the privacy-preserving data mining (PPDM) literature with the clear goal of providing good classification.

  • On the generic construcion of identity-based signatures with additional properties

     Galindo, David; Herranz Sotoca, Javier; Kiltz, Eike
    Advances in mathematics
    Date of publication: 2010-11
    Journal article

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  • Partial symbol ordering distance

     Herranz Sotoca, Javier; Nin Guerrero, Jordi
    International Conference on Modeling Decisions for Artificial Intelligence
    Presentation's date: 2009-12
    Presentation of work at congresses

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    Nowadays sequences of symbols are becoming more important, as they are the standard format for representing information in a large variety of domains such as ontologies, sequential patterns or non numerical attributes in databases. Therefore, the development of new distances for this kind of data is a crucial need. Recently, many similarity functions have been proposed for managing sequences of symbols; however, such functions do not always hold the triangular inequality. This property is a mandatory requirement in many data mining algorithms like clustering or k-nearest neighbors algorithms, where the presence of a metric space is a must. In this paper, we propose a new distance for sequences of (non-repeated) symbols based on the partial distances between the positions of the common symbols. We prove that this Partial Symbol Ordering distance satisfies the triangular inequality property, and we finally describe a set of experiments supporting that the new distance outperforms the Edit distance in those ecenarios where sequence similarity is related to the positions occupied by the symbols.

  • Distributed privacy-preserving methods for statistical disclosure control

     Herranz Sotoca, Javier; Nin Guerrero, Jordi; Torra Raventós, Vicenç
    International Workshop on Data Privacy Management
    Presentation's date: 2009-09-23
    Presentation of work at congresses

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    A cryptographic solution for private distributed simple meeting scheduling  Open access

     Herranz Sotoca, Javier; Matwin, Stan; Meseguer González, Pedro; Nin Guerrero, Jordi
    International Conference of the Catalan Association for Artificial Intelligence
    Presentation's date: 2009
    Presentation of work at congresses

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    Meeting scheduling is a suitable application for distributed computation motivated by its privacy requirements. Previous work on this problem have considered some cryptographic and conceptually clear approach to solve a simple case of Meeting Scheduling, even achieving complete privacy.

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    Ideal homogeneous access structures constructed from graphs  Open access

     Herranz Sotoca, Javier
    Journal of universal computer science
    Date of publication: 2009
    Journal article

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    Starting from a new relation between graphs and secret sharing schemes introduced by Xiao, Liu and Zhang, we show a method to construct more general ideal homogeneous access structures. The method has some advantages: it efficiently gives an ideal homogeneous access structure for the desired rank, and some conditions can be imposed (such as forbidden or necessary subsets of players), even if the exact composition of the resulting access structure cannot be fully controlled. The number of homogeneous access structures that can be constructed in this way is quite limited; for example, we show that (t, l)-threshold access structures can be constructed from a graph only when t = 1, t = l - 1 or t = l.

  • Partial symbol ordering distance

     Herranz Sotoca, Javier; Nin Guerrero, Jordi
    Lecture notes in computer science
    Date of publication: 2009
    Journal article

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  • On the transferability of private signatures

     Herranz Sotoca, Javier
    Information sciences
    Date of publication: 2009-05
    Journal article

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  • The Kurosawa-Desmedt key encapsulation is not chosen-ciphertext secure

     Choi, SG; Herranz Sotoca, Javier; Hofheinz, D; Hwang, JY; Kiltz, E; Lee, DH; Yung, M
    Information processing letters
    Date of publication: 2009-07
    Journal article

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  • Flaws in some self-healing key distribution schemes with revocation

     Daza Fernandez, Vanesa; Herranz Sotoca, Javier; Saez Moreno, German
    Information processing letters
    Date of publication: 2009-05
    Journal article

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  • A new algorithm to search for small nonzero |x^3 - y^2| values

     Jiménez, I; Herranz Sotoca, Javier; Saez Moreno, German
    Mathematics of computation
    Date of publication: 2009-01
    Journal article

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  • Towards a more realistic disclosure risk assessment

     Nin Guerrero, Jordi; Herranz Sotoca, Javier; Torra Raventós, Vicenç
    Privacy in Statistical Databases
    Presentation's date: 2008-09-25
    Presentation of work at congresses

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  • Attribute selection in multivariate microaggregation

     Nin Guerrero, Jordi; Herranz Sotoca, Javier; Torra Raventós, Vicenç
    International Workshop on Privacy and Anonymity in Information Society
    Presentation's date: 2008
    Presentation of work at congresses

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    Microaggregation is one of the most employed microdata protection methods. The idea is to build clusters of at least k original records, and then replace them with the centroid of the cluster. When the number of attributes of the dataset is large, a common practice is to split the dataset into smaller blocks of attributes. Microaggregation is successively and independently applied to each block. In this way, the effect of the noise introduced by microaggregation is reduced, but at the cost of losing the k-anonymity property. The goal of this work is to show that, besides of the specific microaggregation method employed, the value of the parameter k, and the number of blocks in which the dataset is split, there exists another factor which can influence the quality of the microaggregation: the way in which the attributes are grouped to form the blocks. When correlated attributes are grouped in the same block, the statistical utility of the protected dataset is higher. In contrast, when correlated attributes are dispersed into different blocks, the achieved anonymity is higher, and, so, the disclosure risk is lower. We present quantitative evaluations of such statements based on different experiments on real datasets.

  • On the disclosure risk of multivariate microaggregation

     Nin Guerrero, Jordi; Herranz Sotoca, Javier; Torra Raventós, Vicenç
    Data and knowledge engineering
    Date of publication: 2008-07-22
    Journal article

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    The aim of data protection methods is to protect a microdata file both minimizing the disclosure risk and preserving the data utility. Microaggregation is one of the most popular such methods among statistical agencies. Record linkage is the standard mechanism used to measure the disclosure risk of a microdata protection method. However, only standard, and quite generic, record linkage methods are usually considered, whereas more specific record linkage techniques can be more appropriate to evaluate the disclosure risk of some protection methods. In this paper we present a new record linkage technique, specific for microaggregation, which obtains more correct links than standard techniques. We have tested the new technique with MDAV microaggregation and two other microaggregation methods, based on projections, that we propose here for the first time. The direct consequence is that these microaggregation methods have a higher disclosure risk than believed up to now.

  • How to group attributes in multivariate microaggregation

     Nin Guerrero, Jordi; Herranz Sotoca, Javier; Torra Raventós, Vicenç
    International journal of uncertainty fuzziness and knowledge-based systems
    Date of publication: 2008-04-01
    Journal article

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  • On the computational security of a distributed key distribution scheme

     Daza Fernandez, Vanesa; Herranz Sotoca, Javier; Saez Moreno, German
    IEEE transactions on computers
    Date of publication: 2008-08
    Journal article

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