Efficient Privacy-Preserving Approximation of the Kidney Exchange Problem

The kidney exchange problem (KEP) seeks to find possible exchanges among pairs of patients and their incompatible kidney donors while meeting specific optimization criteria such as maximizing the overall number of possible transplants. Recently, several privacy-preserving protocols for solving the KEP have been proposed. However, the protocols known to date lack scalability in practice since the KEP is an NP-complete problem. We address this issue by proposing a novel privacy-preserving protocol which computes an approximate solution for the KEP that scales well for the large numbers of patient-donor pairs encountered in practice. As opposed to prior work on privacy-preserving kidney exchange, our protocol is generic w.r.t.\ the security model that can be employed. Compared to the most efficient privacy-preserving protocols for kidney exchange existing to date, our protocol is entirely data oblivious and it exhibits a far superior run time performance. As a second contribution, we use a real-world data set to simulate the application of our protocol as part of a kidney exchange platform, where patient-donor pairs register and de-register over time, and thereby determine its approximation quality in a real-world setting.Comment: Accepted at ACM Asia Conference on Computer and Communications Security (ASIA CCS 2024

Does multidimensional forced-choice prevent faking? Comparing the susceptibility of the multidimensional forced-choice format and the rating scale format to faking

A common concern with self-reports of personality traits in selection contexts is faking. The multidimensional forced-choice (MFC) format has been proposed as an alternative to rating scales (RS) that could prevent faking. The goal of this study was to compare the susceptibility of the MFC format and RS format to faking in a simulated high-stakes setting when using normative scoring for both formats. Participants were randomly assigned to three groups (total N = 1,867) and filled out the Big Five Triplets once under an honest instruction and once under a fake-good instruction. Latent mean differences between the honest and fake-good administrations indicated that the Big Five domains were faked in the expected direction. Faking effects for all traits were larger for RS compared to MFC. Faking effects were also larger for the MFC version with mixed triplets compared to the MFC version with triplets that were fully matched regarding their social desirability. The MFC format does not prevent faking completely, but it reduces faking substantially. Faking can be further reduced in the MFC format by matching the items presented in a block regarding their social desirability

BoostReduce - A Framework For Strong Lattice Basis Reduction

In this paper, we propose a new generic reduction framework BoostReduce for strong lattice basis reduction. At the core of our new framework is an iterative method which uses a newly-developed algorithm for finding short lattice vectors and integrating them efficiently into an improved lattice basis. We present BoostBKZ as an instance of BoostReduce using the Block-Korkine-Zolotarev (BKZ) reduction. BoostBKZ is tailored to make effective use of modern computer architectures in that it takes advantage of multiple threads. Experimental results of BoostBKZ show a significant reduction in running time while maintaining the quality of the reduced lattice basis in comparison to the traditional BKZ reduction algorithm

Solving the Kidney Exchange Problem Using Privacy-Preserving Integer Programming (Updated and Extended Version)

The kidney exchange problem (KEP) is to find a constellation of exchanges that maximizes the number of transplants that can be carried out for a set of pairs of patients with kidney disease and their incompatible donors. Recently, this problem has been tackled from a privacy perspective in order to protect the sensitive medical data of patients and donors and to decrease the potential for manipulation of the computing of the exchanges. However, the proposed approaches to date either only compute an approximative solution to the KEP or they suffer from a huge decrease in performance. In this paper, we suggest a novel privacy-preserving protocol that computes an exact solution to the KEP and significantly outperforms the other existing exact approaches. Our novel protocol is based on Integer Programming which is the most efficient method for solving the KEP in the non privacy-preserving case. We achieve an improved performance compared to the privacy-preserving approaches known to date by extending the output of the ideal functionality to include the termination decisions of the underlying algorithm. We implement our protocol in the SMPC benchmarking framework MP-SPDZ and compare its performance to the existing protocols for solving the KEP. In this extended version of our paper, we also evaluate whether and if so how much information can be inferred from the extended output of the ideal functionality.Comment: This is the updated and extended version of the work published in 19th Annual International Conference on Privacy, Security and Trust (PST2022), August 22-24, 2022, Fredericton, Canada / Virtual Conference, https://doi.org/10.1109/PST55820.2022.985196

Monitoring der Arbeitsmarktöffnung - Auswirkungen auf Beschäftigungsformen und auf Lohndumping

Veränderungen am österreichischen Arbeitsmarkt im Zuge der Arbeitsmarktliberalisierung – Qualitative Einschätzungen aus Expertinnensicht. Die Veränderungen im Zuge der Arbeitsmarktöffnung werden als moderat beurteilt, so der allgemeine Tenor verschiedenster ExpertInnen. Eine besondere Dynamisierung am österreichischen Arbeitsmarkt beispielsweise durch eine Verdrängung inländischer Arbeitskräfte durch Neuzugewanderte aus dem EU-8 Raum wird seitens der ExpertInnen nicht im größeren Maße beobachtet. Österreich stellt im europäischen Vergleich ein wichtiges ‚Empfängerland‘ für Entsendungen von ArbeitnehmerInnen dar. Laut einer europaweiten Studie werden deutlich mehr ArbeitnehmerInnen nach Österreich entsandt, als von Österreich aus in andere Arbeitsmärkte. Die Nettobilanz der Entsendungen ist für Österreich negativ und lag im Jahr 2009 bei etwa -26.000. Die Bekämpfung von Lohn- und Sozialdumping in Österreich erhielt mit Mai 2011 mit dem Lohn- und Sozialdumpingbekämpfungsgesetz (LSDB-G) eine neue gesetzliche Grundlage. Im Zentrum dieser Neuregelung steht der Verwaltungsstraftatbestand der Unterschreitung des Grundlohns

Muscular involvement assessed by MRI correlates to motor function measurement values in oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy (OPMD) is a progressive skeletal muscle dystrophy characterized by ptosis, dysphagia, and upper and lower extremity weakness. We examined eight genetically confirmed OPMD patients to detect a MRI pattern and correlate muscle involvement, with validated clinical evaluation methods. Physical assessment was performed using the Motor Function Measurement (MFM) scale. We imaged the lower extremities on a 1.5T scanner. Fatty replacement was graded on a 4-point visual scale. We found prominent affection of the adductor and hamstring muscles in the thigh, and soleus and gastrocnemius muscles in the lower leg. The MFM assessment showed relative mild clinical impairment, mostly affecting standing and transfers, while distal motor capacity was hardly affected. We observed a high (negative) correlation between the validated clinical scores and our visual imaging scores suggesting that quantitative and more objective muscle MRI might serve as outcome measure for clinical trials in muscular dystrophie

Beschäftigungssituation von Personen mit Migrationshintergrund in Wien

BESCHÄFTIGUNGSSITUATION VON PERSONEN MIT MIGRATIONSHINTERGRUND IN WIEN Beschäftigungssituation von Personen mit Migrationshintergrund in Wien / Riesenfelder, Andreas (Rights reserved) ( -

Analysis of authentication and key establishment in inter-generational mobile telephony

Second (GSM), third (UMTS), and fourth-generation (LTE) mobile telephony protocols are all in active use, giving rise to a number of interoperation situations. Although the standards address roaming by specifying switching and mapping of established security context, there is not a comprehensive specification of which are the possible interoperation cases. Nor is there comprehensive specification of the procedures to establish security context (authentication and short-term keys) in the various interoperation scenarios. This paper systematically enumerates the cases, classifying them as allowed, disallowed, or uncertain with rationale based on detailed analysis of the specifications. We identify the authentication and key agreement procedure for each of the possible cases. We formally model these scenarios and analyze their security, in the symbolic model, using the tool ProVerif. We find two scenarios that inherit a known false base station attack. We find an attack on the CMC message of another scenario

The Ursinus Weekly, October 2, 1950

B-listers roll up big 63-40 victory over Dean\u27s team • Enrollment drops to 805; Freshmen number 197 • Pre-medders plan to present talks at their meetings • Co-editors of 1950 yearbook announce appointment of 13 department leaders • Japanese educator visits F. I. Sheeder and College • Y members clean recreation center • Curfew notice • Editor announces positions available on Lantern staff • Improper parkers served notice • Y schedules events for near future; Rally Wednesday • Thespians to hold reception Tuesday at Super House • Omwake leaves Ursinus to accept Virginia post • Robert Rosenberger confined to St. Joseph\u27s Hospital, Reading • Veterans notices • New course offered • Editorial: Destiny; Welcome • Councils clarify freshman customs • Frosh girl hails from Iraq • Scribe pens WSGA notes • Y reception committee expands activity; Wins plaudits for its freshmen program • Ursinus grad gains Bowling Green post • Public causes problems for seeing eye dogs • In memoriam • IRC plans Lehigh trip to hear talk on China • Whistler and cohorts boost morale as fighting spirit invades campus • Studio Cottage singers • Gurzynski first alumnus to guide Bears since 1931 • Booters start practice under genial Dr. Baker • Drexel whips Bears 26-0 to open \u2750 grid season • Gerry Roughton escapes Korean crisis; Evacuates Seoul during red onslaught • ETS announces law admission and grad record exam dates • Pancoast constructs new home; Summer work aids completionhttps://digitalcommons.ursinus.edu/weekly/1546/thumbnail.jp