MS/MS studies on the selective on-line detection of sesquiterpenes using a Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS)

A Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS) was used to investigate the feasibility of selective on-line detection of a series of seven sesquiterpenes (SQTs). These SQTs were chemically ionized by either H3O+ or NO+ reagent ions in the FA, resulting among others in protonated SQT and SQT molecular ions, respectively. These and other Chemical Ionization (CI) product ions were subsequently subjected to dissociation by collisions with Ar atoms in the collision cell of the tandem mass spectrometer. The fragmentation spectra show similarities with mass spectra obtained for these compounds with other instruments such as a Proton Transfer Reaction-Linear Ion Trap (PTR-LIT), a Proton Transfer Reaction-Mass Spectrometer (PTR-MS), a Triple Quadrupole-Mass Spectrometer (QqQ-MS) and a Selected Ion Flow Tube-Mass Spectrometer (SIFT-MS). Fragmentation of protonated SQT is characterized by fragment ions at the same masses but with different intensities for the individual SQT. Distinction of SQTs is based on well-chosen intensity ratios and collision energies. The fragmentation patterns of SQT molecular ions show specific fragment ion tracers at m/z 119, m/z 162, m/z 137 and m/z 131 for alpha-cedrene, delta-neoclovene, isolongifolene and alpha-humulene, respectively. Consequently, chemical ionization of SQT by NO+, followed by MS/MS of SQT(+) seems to open a way for selective quantification of SQTs in mixtures

De invoering van het alcoholslot in België: literatuurstudie over de effectiviteit

De toepassing van alcohol ontstekingsinterlocksystemen beter bekend als alcoholsloten is in opmars in de Westerse wereld alsook bij ons in België. De vraag is of deze systemen het doel bereiken waarvoor ze ontworpen zijn: namelijk een vermindering van het aantal verkeersongevallen en –slachtoffers door een daling van de recidivismegraad van rijden onder invloed (ROI). Om hier een bevestigend antwoord op te geven is verder onderzoek in de vorm van gerandomiseerde gecontroleerde studies noodzakelijk. De resultaten beschikbaar op dit moment tonen dat dit systeem in staat is een daling van het ROI te bewerkstelligen wanneer het toestel aanwezig is in de wagen; echter na verwijdering wordt geen langdurig effect gezien en hervallen de meeste overtreders. De combinatie met een omkaderingsprogramma zou wel in staat zijn een gedragsverandering te bereiken en zo ook een effect op lange termijn bewerkstelligen. Het is echter bijzonder moeilijk om een statistisch significant verschil aan te tonen en extrapolatie toe te laten gezien de lage participatiegraad van de overtreders, de selectiebias aanwezig in niet gerandomiseerde studies en het aantal geobserveerde dropouts. Een alcoholslot heeft mogelijkheden in de aanpak van ROI. Om dit effect aan te tonen dient het op grotere schaal geïmplementeerd en geëvalueerd te worden. Op heden kan besloten worden dat dit middel effectief is in de preventie van ROI zolang het aanwezig is in het voertuig. Het heeft als belangrijk voordeel dat het overtreders niet limiteert in hun professionele en sociale activiteiten. Bovendien kan een positieve gedragsverandering met effect op lange termijn verwacht worden indien het geïmplementeerd wordt in combinatie met de reeds bestaande hulpprogramma

Analyzing Masked Ciphers Against Transition and Coupling Effects

This paper discusses how to analyze the probing security of masked symmetric primitives against the leakage effects from CHES 2018; glitches, transitions, and coupling effects. This is illustrated on several architectures of ciphers like PRESENT, AES, and ASCON where we transform glitch-extended probing secure maskings into transition and/or coupling secure ones. The analysis uses linear cryptanalytic methods and the diffusion layers of the cipher to efficiently protect against the advanced leakage effects

A Purchaser for Resale Is a Consumer Protected by DTPA.

Abstract Forthcoming

The Random Fault Model

In this work, we introduce the random fault model - a more advanced fault model inspired by the random probing model, where the adversary can fault all values in the algorithm but the probability for each fault to occur is limited. The new adversary model is used to evaluate the security of side-channel and fault countermeasures such as Boolean masking, error detection techniques, error correction techniques, multiplicative tags, and shuffling methods. The results of the security analysis reveal new insights both in the novel random fault model as well as in the established random probing model including: shuffling masked implementations does not significantly improve the random probing security over regular masking; error correction providing little security when faults target more bits (versus the significant improvement when using error detection); and the order in which masking and duplication are applied providing a trade-off between random probing and fault security. Moreover, the results also explain the experimental results from CHES 2022 and find weaknesses in the shuffling method from SAMOS 2021

Threshold Implementations with Non-Uniform Inputs

Modern block ciphers designed for hardware and masked with Threshold Implementations (TIs) provide provable security against first-order attacks. However, the application of TIs leaves designers to deal with a trade-off between its security and its cost, for example, the process to generate its required random bits. This generation cost comes with an increased overhead in terms of area and latency. Decreasing the number of random bits for the masking allows to reduce the aforementioned overhead. We propose to reduce the randomness to mask the secrets, like the plaintext. For that purpose, we suggest relaxing the requirement for the uniformity of the input shares and reuse randomness for their masking in first-order TIs. We apply our countermeasures to first-order TIs of the Prince and Midori64 ciphers with three shares. Since the designs with non-uniform masks are no longer perfect first-order probing secure, we provide further analysis by calculating bounds on the advantage of a noisy threshold-probing adversary. We then make use of the PROLEAD tool, which implements statistical tests verifying the robust probing security to compare its output with our estimates. Finally, we evaluate the designs on FPGA to highlight the practical security of our solution. We observe that their security holds while requiring four times less randomness over uniform TIs

Prelude to Marvellous (With the Designers\u27 Commentary, Two Bonus Tracks, and a Foretold Prophecy)

This epos tells the origin story of Rescue, a family of cryptographic algorithms in the Marvellous cryptoverse

Resilient Uniformity: Applying Resiliency in Masking

Threshold Implementations are known countermeasures defending against side-channel attacks via the use of masking techniques. While sufficient properties are known to defend against first-order side-channel attacks, it is not known how to achieve higher-order security. This work generalizes the Threshold Implementation notion of uniformity and proves it achieves second-order protection. The notion is applied to create a second-order masking of the PRESENT cipher with a low randomness cost