Finding Collisions in a Quantum World: Quantum Black-Box Separation of Collision-Resistance and One-Wayness

Since the celebrated work of Impagliazzo and Rudich (STOC 1989), a number of black-box impossibility results have been established. However, these works only ruled out classical black-box reductions among cryptographic primitives. Therefore it may be possible to overcome these impossibility results by using quantum reductions. To exclude such a possibility, we have to extend these impossibility results to the quantum setting. In this paper, we study black-box impossibility in the quantum setting. We first formalize a quantum counterpart of fully-black-box reduction following the formalization by Reingold, Trevisan and Vadhan (TCC 2004). Then we prove that there is no quantum fully-black-box reduction from collision-resistant hash functions to one-way permutations (or even trapdoor permutations). We take both of classical and quantum implementations of primitives into account. This is an extension to the quantum setting of the work of Simon (Eurocrypt 1998) who showed a similar result in the classical setting

Wear and corrosion behaviour of Ti-13Nb-13Zr and Ti-6Al-4V alloys in simulated physiological solution

Wear and corrosion behaviour of cold-rolled Ti-13Nb-13Zr alloy, with martensitic microstructure, and Ti-6Al-4V ELI alloy, in martensitic and two-phase (alpha + beta) microstructural conditions, was studied in a Ringer's solution. The wear experiments were performed at room temperature with a normal load of 40 N and sliding speeds 0.26. 0.5 and 1.0 m/s. The corrosion behaviour was studied at 37 degrees C using open circuit potential-time measurements and potentiodynamic polarization. It was found that Ti-13Nb-13Zr alloy has a substantially lower wear resistance than Ti-6Al-4V ELI alloy in both microstructural conditions. Surface damage extent increases with sliding speed increase and is always smallest for martensitic Ti-6Al-4V ELI alloy with highest hardness. Both alloys exhibit spontaneous passivity in Ringer's solution. Corrosion potential values are similar for all three materials. However, Ti-13Nb-13Zr and martensitic Ti-6Al-4V ELI alloys show improved corrosion resistance comparatively to Ti-6Al-4V ELI alloy with (alpha + beta) microstructure. Martensitic Ti-6Al-4V ELI alloy possesses the best combination of both corrosion and wear resistance, although its corrosion resistance is found to be slightly higher than that of the Ti-13Nb-13Zr alloy

Interobserver agreement of transvaginal ultrasound and magnetic resonance imaging in local staging of cervical cancer

Objective: To evaluate interobserver agreement for the assessment of local tumor extension in women with cervical cancer, among experienced and less experienced observers, using transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI). Methods: The TVS observers were all gynecologists and consultant ultrasound specialists, six with and seven without previous experience in cervical cancer imaging. The MRI observers were five radiologists experienced in pelvic MRI and four less experienced radiology residents without previous experience in MRI of the pelvis. The less experienced TVS observers and all MRI observers underwent a short basic training session in the assessment of cervical tumor extension, while the experienced TVS observers received only a written directive. All observers were assigned the same images from cervical cancer patients at all stages (n = 60) and performed offline evaluation to answer the following three questions: (1) Is there a visible primary tumor? (2) Does the tumor infiltrate > ⅓ of the cervical stroma? and (3) Is there parametrial invasion? Interobserver agreement within the four groups of observers was assessed using Fleiss kappa (κ) with 95% CI. Results: Experienced and less experienced TVS observers, respectively, had moderate interobserver agreement with respect to tumor detection (κ (95% CI), 0.46 (0.40–0.53) and 0.46 (0.41–0.52)), stromal invasion > ⅓ (κ (95% CI), 0.45 (0.38–0.51) and 0.53 (0.40–0.58)) and parametrial invasion (κ (95% CI), 0.57 (0.51–0.64) and 0.44 (0.39–0.50)). Experienced MRI observers had good interobserver agreement with respect to tumor detection (κ (95% CI), 0.70 (0.62–0.78)), while less experienced MRI observers had moderate agreement (κ (95% CI), 0.51 (0.41–0.62)), and both experienced and less experienced MRI observers, respectively, had good interobserver agreement regarding stromal invasion (κ (95% CI), 0.80 (0.72–0.88) and 0.71 (0.61–0.81)) and parametrial invasion (κ (95% CI), 0.69 (0.61–0.77) and 0.71 (0.61–0.81)). Conclusions: We found interobserver agreement for the assessment of local tumor extension in patients with cervical cancer to be moderate for TVS and moderate-to-good for MRI. The level of interobserver agreement was associated with experience among TVS observers only for parametrial invasion. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology

A Combinatorial Approach to Quantum Random Functions

Quantum pseudorandom functions (QPRFs) extend the classical security of a PRF by allowing the adversary to issue queries on input superpositions. Zhandry [Zhandry, FOCS 2012] showed a separation between the two notions and proved that common construction paradigms are also quantum secure, albeit with a new ad-hoc analysis. In this work we revisit the question of constructing QPRFs and propose a new method starting from small-domain (classical) PRFs: At the heart of our approach is a new domain-extension technique based on bipartite expanders. Interestingly, our analysis is almost entirely classical. As a corollary of our main theorem, we obtain the first (approximate) key-homomorphic quantum PRF based on the quantum intractability of the learning with errors problem

THE MADINAH CHARTER, NOT A CONSTITUTION OF ISLAMIC STATE

This paper will state that Madinah Charter is not a constitutionthat is referred as the model in upholding islamic state. Usingsemiotic method, this paper will conclude that every dictumwithin the Madinah Charter has sort of code of conducts thatfunctions to provide social security within the Madinah societyat that time. Nevertheless, current politics could stillappropriate the fundamental values within the MadinahCharter especially in implementing justice-based governance,equality before the law, open public participation and so forth.Excessive intention of certain Muslim group, including inIndonesia, to uphold khilafah system is not in accordance withthe spirit of the Madinah charter. It is because the khilafah isbased on the monarchical system, which does not involve thepeople within the elections and so on as it is implied from theMadinah Charter.Keywords: the madinah charter, constitution, Islamic stateIntroductio