Orange S.A.

About: Orange S.A. is a company organization based out in Paris, France. It is known for research contribution in the topics: Terminal (electronics) & Signal. The organization has 6735 authors who have published 9190 publications receiving 156440 citations. The organization is also known as: Orange SA & France Télécom.

Analysis, improvement and simplification of Prêt à voter with Paillier encryption

Abstract: In this paper, we analyse information leakage in Ryan's Pret a Voter with Paillier encryption scheme (PAV-Paillier). Our analysis shows that although PAV-Paillier seems to achieve a high level of voter privacy at first glance, it might still leak voter's choice information in some circumstances. Some threats are trivial and have appeared in the literature, but others are more complicated because colluding adversaries may apply combined attacks. Several strategies have been suggested to mitigate these threats, but we have not resolved all the threats. We leave those unsolved threats as open questions. In order to describe our analysis in a logical manner, we will introduce an information leakage model to aid our analysis. We suggest that this model can be applied to analyse information leakage in other complex mixnet based e-voting schemes as well. Furthermore, we introduce a simplification of PAV-Paillier. In our proposal, without degrading security properties such as voter privacy, verifiability and reliability, we no longer need to apply the homomorphic property to absorb the voter's choice index into the onion, thus we step back to employ the ElGamal encryption. This results in a simpler and more straightforward threshold cryptosystem. Some other attractive properties of our proposal scheme are: unlike traditional Pret a Voter schemes, the candidate list in our scheme can be in alphabetical order. Our scheme not only handles approval elections, but also it handles ranked elections (e.g. Single Transferable Voting). Furthermore, our scheme mitigates the randomisation attack.

Analysis of the Peak-To-Average Power Ratio for OFDM/OQAM

Abstract: OFDM/OQAM is now a recognized alternative to conventional OFDM for the transmission of signals over multipath fading channels. Indeed with OFDM/OQAM an appropriate pulse-shaping can be introduced to fight against time and frequency dispersion. This paper focuses on a theoretical and experimental analysis of the peak-to-average power ratio (PAPR) for OFDM/OQAM. It is shown that the best complementary cumulative density function (CCDF) is obtained with orthogonal prototype filters.

Selective video encryption based on advanced video coding

Abstract: Advanced Video Coding is recently announced and widely used, although the according protection means have not been developed thoroughly. In this paper, a selective encryption scheme is constructed on Advanced Video Coding. During AVC encoding, such sensitive data as intra-prediction mode, residue data, inter-prediction mode and motion vector are partially encrypted. This encryption scheme keeps secure against brute-force attack, replacement attack or known-plaintext attack, combines encryption process with compression process with low cost, and keeps the file format unchanged with some direct operations (such as displaying, time seeking, copying, cutting, etc.) supported. These properties make it suitable for secure video transmission.

Multilingual PSOLA text-to-speech system

Abstract: Work done at CNET on developing multilingual concatenation-based PSOLA TTS (text-to-speech) systems well adapted to their use in interactive voice services is reviewed. A new system architecture SYC (synthesis control) has been specifically designed for assuring real-time, multichannel, and interactive operation. The data control and transfer methods within the system are now fully independent of the content of the modules, allowing for an easy adaptation of the system to multilingual operation. A complete version has been developed for German, and mixed systems have been elaborated for Italian and English in collaboration with other laboratories, using the same PSOLA synthesizer as for French. The overall quality of the French version has been improved both in naturalness (optimization of the linguistico-prosodic processings) and in articulation accuracy (use of longer units to be concatenated). An automatic segmentation procedure has been developed for the rapid building of new repertories of speech from recordings by new speakers, i.e., for the creation of new synthetic voices. >

On the base station selection and base station sharing in self-configuring networks

Abstract: We model the interaction of several radio devices aiming to obtain wireless connectivity by using a set of base stations (BS) as a non-cooperative game. Each radio device aims to maximize its own spectral efficiency (SE) in two different scenarios: First, we let each player to use a unique BS (BS selection) and second, we let them to simultaneously use several BSs (BS Sharing). In both cases, we show that the resulting game is an exact potential game. We found that the BS selection game posses multiple Nash equilibria (NE) while the BS sharing game posses a unique one. We provide fully decentralized algorithms which always converge to a NE in both games. We analyze the price of anarchy and the price of stability for the case of BS selection. Finally, we observed that depending on the number of transmitters, the BS selection technique might provide a better global performance (network spectral efficiency) than BS sharing, which suggests the existence of a Braess type paradox.