21 research outputs found

    Nanosecond-Level Resilient GNSS-Based Time Synchronization in Telecommunication Networks Through WR-PTP HA

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    In recent years, the push for accurate and reliable time synchronization has gained momentum in critical infrastructures, especially in telecommunication networks, driven by the demands of 5G new radio and next-generation technologies that rely on submicrosecond timing accuracy for radio access network (RAN) nodes. Traditionally, atomic clocks paired with global navigation satellite systems (GNSS) timing receivers have served as grand master clocks, supported by dedicated network timing protocols. However, this approach struggles to scale with the increasing numbers of RAN intermediate nodes. To address scalability and high-accuracy synchronization, a more cost-effective and capillary solution is needed. Standalone GNSS timing receivers leverage ubiquitous satellite signals to offer stable timing signals but can expose networks to radio-frequency attacks due to the consequent proliferation of GNSS antennas. Our research introduces a solution by combining the white rabbit precise time protocol with a backup timing source logic acting in case of timing disruptive attacks against GNSS for resilient GNSS-based network synchronization. It has been rigorously tested against common jamming, meaconing, and spoofing attacks, consistently maintaining 2 ns relative synchronization accuracy between nodes, all without the need for an atomic clock

    Satellite-derived Time for Enhanced Telecom Networks Synchronization: the ROOT Project

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    Satellite-derived timing information plays a determinant role in the provisioning of an absolute time reference to telecommunications networks, as well as in a growing set of other critical infrastructures. In light of the stringent requirements in terms of time, frequency, and phase synchronization foreseen in upcoming access network architectures (i.e., 5G), Global Navigation Satellite System (GNSS) receivers are expected to ensure enhanced accuracy and reliability not only in positioning but also in timing. High-end GNSS timing receivers combined with terrestrial cesium clocks and specific transport protocols can indeed satisfy such synchronization requirements by granting sub-nanosecond accuracy. As a drawback, the network infrastructure can be exposed to accidental interferences and intentional cyber-attacks. Within this framework, the ROOT project investigates the effectiveness and robustness of innovative countermeasures to GNSS and cybersecurity threats within a reference network architecture

    Rectangular Attack on VOX

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    VOX has been submitted to the NIST Round 1 Additional Signature of the Post-Quantum Signature Competition in June 2023. VOX is a strengthened variant of UOV which uses the Quotient-Ring (QR) setting to reduce the public-key size. At the end of August 2023, Furue and Ikamatsu posted on the NIST mailing-list a post, indicating that the parameters of VOX can be attacked efficiently using the rectangular attack in the QR setting. In this note, we explain the attack in the specific case of VOX, we detail the complexity, and show that as Furue and Ikematsu indicated, the attack can be completely avoided by adding one more constraint on the parameter selection. Finally, we show that this constraint does not increase the sizes of the public keys or signature

    Mitigating Software Integrity Attacks With Trusted Computing in a Time Distribution Network

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    Time Distribution Networks (TDNs) evolve as new technologies occur to ensure more accurate, reliable, and secure timing information. These networks typically exploit several distributed time servers, organized in a master-slave architecture, that communicate via dedicated timing protocols. From the security perspective, timing data must be protected since its modification or filtering can lead to grave consequences in different time-based contexts, such as health, energy, finance, or transportation. Thus, adequate countermeasures must be employed in all the stages and systems handling timing data from its calculation until it reaches the final users. We consider a TDN offering highly accurate (nanosecond level) time synchronization through specific time unit devices that exploit terrestrial atomic or rubidium clocks and Global Navigation Satellite Systems (GNSS) receivers. Such devices are appealing targets for attackers, who might exploit various attack vectors to compromise their functionality. We individuate three possible software integrity attacks against time devices, and we propose a solution to counter them by exploiting the cryptographic Trusted Platform Module (TPM), defined and supported by the Trusted Computing Group. We used remote attestation software for cloud environments, namely the Keylime framework, to verify (periodically) the software daemons running on the time devices (or their configuration) from a trusted node. Experiments performed on a dedicated testbed set up in the ROOT project with customized time unit devices from Seven Solutions (currently Orolia Spain) allow us to demonstrate that exploiting TPMs and remote attestation in the TDNs is not only helpful but is fundamental for discovering some attacks that would remain otherwise undetected. Our work helps thus TDN operators build more robust, accurate, and secure time synchronization services

    Closed hyperthermic intraperitoneal chemotherapy with open abdomen: a novel technique to reduce exposure of the surgical team to chemotherapy drugs.

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    International audienceBACKGROUND: Exposure of the surgical team to toxic drugs during hyperthermic intraperitoneal chemotherapy (HIPEC) remains a matter of great concern. During closed-abdomen HIPEC, operating room staff are not exposed to drugs, but the distribution of the heated liquid within the abdomen is not optimal. With open-abdomen HIPEC, the opposite is true. Although the open-abdomen method is potentially more effective, it has not become a standard procedure because of the risk of exposure of members of the team to drugs. METHODS: We present a new technique (closed HIPEC with open abdomen) which ensures protection against potentially contaminating exposure to liquids, vapours and aerosols, and allows permanent access to the whole abdominal cavity. Its principle is to extend the abdominal surgical wound upwards with a sort of "glove-box". The cutaneous edges of the laparotomy are stapled to a latex "wall expander". The expander is draped over a special L-section metal frame placed above the abdomen. A transparent cover containing a "hand-access" port, like those used in laparoscopic surgery, is fixed inside the frame. RESULTS: In 10 patients, this device proved to be hermetic for both liquids and vapours. Intra-abdominal temperature was maintained between 42 and 43 degrees C during most of the procedure. The whole abdominal cavity was accessible to the surgeon, allowing optimal exposure of all peritoneal surfaces. CONCLUSION: This technique allows optimal HIPEC, while limiting the potential toxic effects for the surgical, medical and paramedical teams

    Psychometric characteristics of the “General Oral Health Assessment Index (GOHAI) » in a French representative sample of patients with schizophrenia

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    Abstract Background The “General Oral Health Assessment Index” (GOHAI) was widely used in clinical or epidemiological studies worldwide, as it was available for use in different languages. Therefore, the aim of this study was to evaluate the psychometric characteristics of the GOHAI in a representative sample of patients with schizophrenia. Methods A total of 90 schizophrenic patients (in-patients and out-patients) were recruited from the participants of the “buccodor study” (NCT02167724) between March and September 2015. They were selected using a random stratified sampling method according to their age, sex, or residential area (urban/rural area). GOHAI validity (construct, predictive, concurrent and known group validity) and internal consistency (reliability) were tested. Test-retest reliability was evaluated in 32 subjects. Results The mean age was 47.34 (SD = 12.17). Internal consistency indicated excellent agreement, with a Cronbach’s α α \alpha value of 0.82 and average inter-item correlation of 0.65. Intraclass correlation coefficients for test-retest reliability with 95% confidence intervals were not significantly different (p > 0.05). Construct validity was supported by three factor that accounted for 60.94% of the variance observed. Predictive validity was corroborated as statistically significant differences were observed between a high GOHAI score, which was associated with self-perceived satisfaction with oral health, lower age and high frequency of toothbrushing. Concurrent validity was corroborated as statistically significant relationships were observed between the GOHAI scores and most objective measures of dental status. For known group validity, they was no significant difference of the mean GOHAI score between out or in-patients (p > 0.05). Conclusion Acceptable psychometric characteristics of the GOHAI could help caregivers to develop ways to improve the Oral Health related Quality Of Life of schizophrenic patients. Trial registration Clinical Trials Gov NCT02167724 . Date registered 17 June, 2014
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