Verifiable Random Functions (VRFs)

A Verifiable Random Function (VRF) is the public-key version of a keyed cryptographic hash. Only the holder of the private key can compute the hash, but anyone with public key can verify the correctness of the hash. VRFs are useful for preventing enumeration of hash-based data structures. This document specifies several VRF constructions that are secure in the cryptographic random oracle model. One VRF uses RSA and the other VRF uses Eliptic Curves (EC).https://datatracker.ietf.org/doc/draft-irtf-cfrg-vrf/First author draf

NSEC5, DNSSEC authenticated denial of existence

The Domain Name System Security Extensions (DNSSEC) introduced two resource records (RR) for authenticated denial of existence: the NSEC RR and the NSEC3 RR. This document introduces NSEC5 as an alternative mechanism for DNSSEC authenticated denial of existence. NSEC5 uses verifiable random functions (VRFs) to prevent offline enumeration of zone contents. NSEC5 also protects the integrity of the zone contents even if an adversary compromises one of the authoritative servers for the zone. Integrity is preserved because NSEC5 does not require private zone-signing keys to be present on all authoritative servers for the zone, in contrast to DNSSEC online signing schemes like NSEC3 White Lies.https://datatracker.ietf.org/doc/draft-vcelak-nsec5/First author draf

Extending BIM for air quality monitoring

As we spend more than 90% of our time inside buildings, indoor environmental quality is a major concern for healthy living. Recent studies show that almost 80% of people in European countries and the United States suffer from SBS (Sick Building Syndrome), which affects physical health, productivity and psychological well-being. In this context, environmental quality monitoring provides stakeholders with crucial information about indoor living conditions, thus facilitating building management along its lifecycle, from design, construction and commissioning to usage, maintenance and end-of-life. However, currently available modelling tools for building management remain limited to static models and lack integration capacities to efficiently exploit environmental quality monitoring data. In order to overcome these limitations, we designed and implemented a generic software architecture that relies on accessible Building Information Model (BIM) attributes to add a dynamic layer that integrates environmental quality data coming from deployed sensors. Merging sensor data with BIM allows creation of a digital twin for the monitored building where live information about environmental quality enables evaluation through numerical simulation. Our solution allows accessing and displaying live sensor data, thus providing advanced functionality to the end-user and other systems in the building. In order to preserve genericity and separation of concerns, our solution stores sensor data in a separate database available through an application programming interface (API), which decouples BIM models from sensor data. Our proof-of-concept experiments were conducted with a cultural heritage building located in Bled, Slovenia. We demonstrated that it is possible to display live information regarding environmental quality (temperature, relative humidity, CO2, particle matter, light) using Revit as an example, thus enabling end-users to follow the conditions of their living environment and take appropriate measures to improve its quality.Pages 244-250

DC Gradiometers for Bomb Detection: Scalar Versus Vectorial

Location of UXO (unexploded ordnance) using its DC magnetic signature requires precise gradiometers: resonant scalar and vectorial fluxgate sensors are used. The needed resolution is 1 nT in 50 000 nTEar th’s field. Scalar gradiometers are very stable, but in some positions the scalar gradient is very small and the target may be overlooked. The disadvantage of the double-sensor fluxgate vectorial gradiometer is its high sensitivity to angular mismatch. This may be partly suppressed by using a 3-axial gradiometer arrangement with 6 sensors, which also gives more information from one reading. We developed field calibration procedures for such an instrument which allow the correction of misalignments down to 0.05 deg. DC gradiometers are typically used for deep and large objects. We demonstrate that they are also able to find small cluster bomb submunitions and that they are less affected by metal scrap than existing eddy-current UXO detectors. The field shape from a small bomb strongly depends on local field inclination; the magnetically hard component is not negligible, so that the signature depends also on the magnetic history and orientation of the target.JRC.G.6-Sensors, radar technologies and cybersecurit

Bomb Detection in Magnetic Soils: AC versus DC Methods

We compare the performance of eddy current metal detectors for finding small bombs and other items of unexploded ordnance (UXO) with the potencial of DC gradiometers of scalar and resonant type. Extensive database of results was collected during laboratory measurements and field trials performed by JRC. There are two main obstacles for bomb detection: false alarms caused by metal clutter and effect of magnetic soil and rocks. A number of soil samples were collected at mine fields and UXO affected areas. Magnetic properties of these soils were examined both in time and frequency domain. The results were compared with the detection depths measured both in soil and in air for various targets. In general, the most difficult soils show frequency dependent susceptibility, which creates signal similar to metal object. We show how to compensate such soils. DC methods give signals between 1 nT and 100 nT. Gradiometer should be used, because often even the natural variations of the Earth's field mask the signature from metal object. Scalar gradiometers need no calibration, but give less information than multi axis vectorial systems. We show Achilles'heel of scalar gradiometers which we believe has never been reported in the literature.JRC.G.6-Security technology assessmen

Chondrosarcomas of the small bones: analysis of 44 patients

BackgroundChondrosarcomas of the small bones of the hands and feet are uncommon and account for less than 2% of all chondrosarcomas in the skeleton; a 4.2% rate of malignant degeneration of enchondromas to secondary chondrosarcomas has been reported. We performed this study to assess the outcome of the patients with chondrosarcomas of the small bones. We hypothesized that the presumed better prognosis of chondrosarcomas in these locations could be biased as the majority of these tumors tend to be of lower grades and are removed when still small sized, and that less aggressive surgery has an adverse effect on local controlMaterials and methodsWe retrospectively studied the files of 44 patients with chondrosarcomas of the small bones of the hands and feet. There were 23 female and 21 male patients with a mean age of 50.9 years (range, 6-86 years). The mean follow-up was 13 years (range, 5-40 years). We recorded the patients’ details including gender and age at diagnosis, type and duration of symptoms, tumor location and histology, type of surgery and complications, and outcome (local recurrences and metastases).ResultsThe most common anatomical location for chondrosarcomas of the hands was the metacarpals and proximal phalanges. The most common presenting symptom was a slowly enlarging palpable mass. Overall, 36 chondrosarcomas were secondary to a pre-existing cartilaginous tumor. Patients with syndromes were affected in younger age compared to the others. The mean age at diagnosis was higher for higher grade chondrosarcomas. Overall, 13 patients (29.5%) experienced a local recurrence; the rate of local recurrence was higher after curettage regardless the histological grade of the tumors. After wide resection of the first local recurrence, five patients experienced local re-recurrence. Five patients (11.4%) experienced lung metastases, two patients at presentation. All these patients had a high grade chondrosarcomas. At the last follow-up, one patient with lung metastases died from disease, and another patient died from unrelated cause.ConclusionsThe patients with chondrosarcomas of the small bones of the hands and feet may have a dismal outcome if treated improperly. A careful treatment planning is required to avoid unnecessary amputations. Curettage is associated with a high rate for local recurrence that should be treated with a more aggressive surgical resection to avoid re-recurrences. Although the risk is low, the patients may develop lung metastases, especially those with higher grade chondrosarcomas, therefore, they should be staged and followed closely

Federated use of hygrothermal monitoring data in mass timber buildings: opportunities and challenges

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