A Privacy-Preserving Contactless Transport Service for NFC Smartphones

International audienceThe development of NFC-enabled smartphones has paved the way to new applications such as mobile payment (m-payment) and mobile ticketing (m-ticketing). However, often the privacy of users of such services is either not taken into account or based on simple pseudonyms, which does not offer strong privacy properties such as the unlinkability of transactions and minimal information leakage. In this paper, we introduce a lightweight privacy-preserving contactless transport service that uses the SIM card as a secure element. Our implementation of this service uses a group signature protocol in which costly cryptographic operations are delegated to the mobile phone

Securing Smartphone Transaction

International audienc

A privacy-enhanced m-transactions architecture for awareness and trust

International audienceGiven the characteristics of the mobile phone market, the development of RFID technology in mobile phones (NFC) could grow quickly and importantly. This paper considers the possible impact of this evolution in term of privacy, and after a few examples, proposes a survey of technology and products of the PC-world intending to offer good privacy characteristics. Then it describes a model and technical architecture, which aims at enhancing privacy in many applications from the vast family of access control/right control applications

Security and trust for mobile phones based on virtualization

National audienceIn this paper, we present a concept of a trusted computing platform aimed for mobile devices. Most of previous works on trusted computing platforms were aimed for computers. The proposed method is based on the existence of a secure element in the mobile, mobile OS virtualization and trusted boot process. Such a platform is feasible and easy to implement if specific requirements are respected

Building Trust in Virtualized Networks

International audienceIn this paper, we propose a new approach, derived from the Trusted Computing Group specifications, to bring trust within Virtualized Networks defined in the European project 4WARD. Many players are involved in this type of networks. Some of the actors may compete with each other while they share the same physical networking resources. This paper focuses on the trust deployment in a physical node. A chain of trust is established from the root of trust to high level applications. The root of trust is based on a small piece of software stored on a hardware chip

Payment and privacy: A key for the development of NFC mobile

International audienceThis paper first introduces a possible evolution of secure personal identification devices, based on RFID technology in the mobiles phones (NFC). Given the characteristics of the mobile phone market, this trend could grow quickly and importantly. This paper considers the possible impact of this evolution in term of privacy, focusing on a typical and important case: payment transactions. This paper sticks to the general approach and role of "card payment system". Yet, it demonstrates that it is possible to improve some of the privacy characteristics of this kind of application. It also outlines the way payment protocol should be designed in order to reach this goal

Système de gestion d’identité numérique

L'invention concerne un procédé pour authentifier un sujet utilisateur d'un terminal de communication, auprès d'un fournisseur de service tel qu'un site internet marchand, dans lequel : - le fournisseur d'accès adresse au terminal une requête de revendication d'identité donnant les attributs de l'identité numérique du sujet devant être fournis ; dans lequel c'est un composant de sécurité actif résidant dans le terminal de communication qui construit la revendication d'identité à partir de données relatives à l'identité numérique du sujet mémorisées dans le terminal et/ou collectées par le composant de sécurité actif auprès d'un ou plusieurs fournisseurs d'identité accessible par internet ; - et dans lequel c'est la revendication d'identité construite par le composant de sécurité actif résidant dans le terminal de communication qui est adressée au fournisseur d'accès pour acceptation

Etude de la variabilité des assemblages de diatomées actuelles dans les lacs d’Ounianga

International audienc

Lake Chad sedimentation and environments during the late Miocene and Pliocene: New evidence from mineralogy and chemistry of the Bol core sediments

International audienceThis study presents mineralogical and geochemical data from a borehole drilled near the locality of Bol (13°27′N, 14°44′E), in the eastern archipelago of the modern Lake Chad (Chad). Samples were taken from a ∼200 m long core section forming a unique sub-continuous record for Central Africa. Among these samples, 25 are dated between 6.4 and 2.4 Ma. Dominant minerals are clays (66% average) mixed with varying amounts of silt and diatomite. The clay fraction consists of Fe-beidellite (87% average), kaolinite, and traces of illite. Clay minerals originate from the erosion of the vertisols that surrounded the paleolake Chad. Sedimentological data indicate that a permanent lake (or recurrent lakes) existed from 6.7 until 2.4 Ma in the vicinity of Bol. By comparison with modern latitudinal distribution of vertisols in Africa the climate was Sudanian-like. Changes in the sedimentation rate suggest a succession of wetter and dryer periods during at least six million years in the region during the critical time period covering the Miocene–Pliocene transition

Diatom, phytolith, and pollen records from a 10Be/9Be dated lacustrine succession in the Chad basin : insight on the Miocene–Pliocene paleoenvironmental changes in Central Africa

International audienceA discontinuous 200 m-long borehole drilled in the Bol Archipelago (13°N, Lake Chad) provided 25 samples, which were dated using the 10Be/9Be method and analyzed for their micro-biological content. The dating provided ages ranging from 6.3 ± 0.1 to 2.6 ± 0.1 Ma, a period contemporaneous with the Pliocene fossil localities located in the current Djurab desert of Chad (16–17°N).Well-preserved diatom assemblages first occurred at 4.7 ± 0.1 Ma and were dominated by the freshwater planktonic genera Aulacoseira and Stephanodiscus until the end of the Pliocene. This supports the recurrence of lacustrine conditions at Bol during all the Pliocene. The presence of pelite and argillaceous deposits in the core before 4.7 ± 0.1 Ma, however, suggests that the lake settled earlier, at least since 6.3 ± 0.1 Ma. The abundance of Afromontane pollen taxa at 4.2 ± 0.1 Ma and the occurrence of trapeziform polylobate phytoliths throughout the sequence suggest significant vegetation inputs from the southern highlands, while the importance of kaolinite in the clay sediments indicates a water supply predominantly from the south during the Pliocene.Phytolith assemblages are all dominated by lobate grass silica short cells and by blocky and elongate types, which attest to the presence of herbaceous-dominated vegetation around Bol and/or in the southern drainage basin during the Pliocene. This result is also supported by the pollen assemblage described at 4.2 ± 0.1 Ma, which shows highest affinity for the savanna biome. Moreover, low values for the Xerophytic grass phytolith index indicate the presence of humid-loving (mesophytic and aquatic) grass communities in this vegetation.At last, significant variations in the abundance of blocky and elongate phytoliths are indicative of local alternations of fully lacustrine and marshy conditions at Bol. Particularly between 3.6 and 2.7 Ma, the abundance of silicified bulliform cells combined with the absence of diatoms support a significant lacustrine reduction at Bol favoring the increasing of local marshy vegetation