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.

Large nonlinear phase shift owing to cascaded χ (2) in quasi-phase-matched bulk LiNbO 3

Abstract: Large nonresonant effective nonlinear indices that are due to cascading have been observed by Z-scan and CCD camera measurements performed on quasi-phase-matched LiNbO3. Positive and negative values of n2cascad were measured at temperatures symmetrically displayed with respect to the optimum phase-matching temperatures (2.39×10-13 and -2.37×10-13 cm2/W, respectively).

Monolithic integration of InGaAsP-InP strained-layer distributed feedback laser and external modulator by selective quantum-well interdiffusion

Abstract: A new approach using a cap-annealing partial disordering technique is demonstrated for 1.55-/spl mu/m multiple-quantum-well (MQW) distributed feedback (DFB) laser-external electroabsorption modulator monolithic integration. Good static performances of the light source (15 mA threshold current, 14-dB on-off ratio for a 4-V voltage swing) are reported using this technique that preserves the material optical and electrical quality. >

On the security of IV dependent stream ciphers

Abstract: Almost all the existing stream ciphers are using two inputs: a secret key and an initial value (IV). However recent attacks indicate that designing a secure IV-dependent stream cipher and especially the key and IV setup component of such a cipher remains a difficult task. In this paper we first formally establish the security of a well known generic construction for deriving an IV-dependent stream cipher, namely the composition of a key and IV setup pseudo-random function (PRF) with a keystream generation pseudo-random number generator (PRNG). We then present a tree-based construction allowing to derive a IV-dependent stream cipher from a PRNG for a moderate cost that can be viewed as a subcase of the former generic construction. Finally we show that the recently proposed stream cipher quad [3] uses this tree-based construction and that consequently the security proof for quad's keystream generation part given in [3] can be extended to incorporate the key and IV setup.

Experimental analysis of the impact of peer-to-peer applications on traffic in commercial IP networks

Abstract: To evaluate the impact of peer-to-peer (P2P) applications on traffic in wide area networks, we analyze measurements from a high speed IP backbone link carrying TCP traffic towards several ADSL areas. The first observations are that the prevalent part of traffic is due to P2P applications (almost 80% of total traffic) and that the usage of network becomes symmetric in the sense that customers are not only clients but also servers. This latter point is observed by the significant proportion of long flows mainly composed of ACK segments. When analyzing the bit rate created by long flows, it turns out that the TCP connections due to P2P applications have a rather small bit rate and that there is no evidence for long range dependence. These facts are intimately related to the way P2P protocols are running. We separately analyze signaling traffic and data traffic. It turns out that by adopting a suitable level of aggregation, global traffic can be described by means of usual tele-traffic models based on M/G/∞ queues with Weibullian service times. Copyright © 2004 AEI