In order to provide different services for the customers, banks embark on a multimedia contact center. Considering that, in this center, where several services such as transferring money, getting statement information and asking for check books are provided, the authentication is of high importance. How to allocate the appropriate authentication method for each customer is one of the challe...

We construct the first Message Authentication Codes (MACs) that are existentially unforgeable against a quantum chosen message attack. These chosen message attacks model a quantum adversary’s ability to obtain the MAC on a superposition of messages of its choice. We begin by showing that a quantum secure PRF is sufficient for constructing a quantum secure MAC, a fact that is considerably harder...

This work proposes innovative permutation-based procedures controlling the Familywise Error rate (FWE). It is proofed that weighted procedures control the FWE if weights are a function of the sufficient statistic. Particularly, we focus on the use of the additional information given by the total variance of each variables. The first proposal considers the use of weights applied to the combining...

We propose the B c → B * u γ decay as the most suitable probe for the flavour changing neutral transition c → uγ. We estimate the short and long distance contributions to this decay within the standard model and we find them to be comparable; this is in contrast to radia-tive decays of D mesons, that are completely dominated by the long distance contributions. Since the c → uγ transition is ver...

Cryptography is the science of secure computation and communication. The scope of cryptosystems, nowadays, ranges from private-key encryption and authentication to more complex systems such as publickey encryption, electronic voting, secure multi-party computation on large data sets, etc. My specialization is in foundations of cryptography, a field that aims at designing cryptographic protocols...

Access to remote IT services through identity federations (IFs) has solid technical foundations such as the Security Assertion Markup Language (SAML). However, reliable delegated user authentication and authorization also pose organizational challenges regarding the quality management of user data. Level of Assurance (LoA) concepts have been adapted and applied to IFs, but their inhomogeneous p...

This paper addresses the following general scenario: A scientist wishes to perform a battery of experiments, each generating a sequential stream of data, to investigate some phenomenon. The scientist would like to control the overall error rate in order to draw statistically-valid conclusions from each experiment, while being as efficient as possible. The between-stream data may differ in distr...

In this paper we establish the existence of path-wise solutions and the uniqueness in law for multidimensional stochastic differential equations driven by a multi-dimensional fractional Brownian motion with Hurst parameter H > 12 .

We propose a watermarking scheme for the authentication of binary images. We transform the image using the binary wavelet transform and partition the resulting coefficients into treestructured blocks. The size of each block is decided by the number of flippable coefficients in the block. The flippable coefficients are found in the frequency domain by investigating high frequency coefficients. A...