Pisces: Private and Compliable Cryptocurrency Exchange

Cryptocurrency exchange platforms such as Coinbase, Binance, enable users to purchase and sell cryptocurrencies conveniently just like trading stocks/commodities. However, because of the nature of blockchain, when a user withdraws coins (i.e., transfers coins to an external on-chain account), all future transactions can be learned by the platform. This is in sharp contrast to conventional stock exchange where all external activities of users are always hidden from the platform. Since the platform knows highly sensitive user private information such as passport number, bank information etc, linking all (on-chain) transactions raises a serious privacy concern about the potential disastrous data breach in those cryptocurrency exchange platforms. In this paper, we propose a cryptocurrency exchange that restores user anonymity for the first time. To our surprise, the seemingly well-studied privacy/anonymity problem has several new challenges in this setting. Since the public blockchain and internal transaction activities naturally provide many non-trivial leakages to the platform, internal privacy is not only useful in the usual sense but also becomes necessary for regaining the basic anonymity of user transactions. We also ensure that the user cannot double spend, and the user has to properly report accumulated profit for tax purposes, even in the private setting. We give a careful modeling and efficient construction of the system that achieves constant computation and communication overhead (with only simple cryptographic tools and rigorous security analysis); we also implement our system and evaluate its practical performance.Comment: 27 pages, 8 figures, 2 tables. To be published in NDSS'24. This is the full version of the conference pape

Impact of high-frequency pumping on anomalous finite-size effects in three-dimensional topological insulators

Lowering of the thickness of a thin-film three-dimensional topological insulator down to a few nanometers results in the gap opening in the spectrum of topologically protected two-dimensional surface states. This phenomenon, which is referred to as the anomalous finite-size effect, originates from hybridization between the states propagating along the opposite boundaries. In this work, we consider a bismuth-based topological insulator and show how the coupling to an intense high-frequency linearly polarized pumping can further be used to manipulate the value of a gap. We address this effect within recently proposed Brillouin-Wigner perturbation theory that allows us to map a time-dependent problem into a stationary one. Our analysis reveals that both the gap and the components of the group velocity of the surface states can be tuned in a controllable fashion by adjusting the intensity of the driving field within an experimentally accessible range and demonstrate the effect of light-induced band inversion in the spectrum of the surface states for high enough values of the pump.Comment: 6 pages, 3 figure

Sulfotanshinone Sodium Injection for Unstable Angina Pectoris: A Systematic Review of Randomized Controlled Trials

Objective. To assess the effect of sulfotanshinone sodium injection for unstable angina. Methods. We searched for published and unpublished studies up to June 2011. We included randomized controlled trials that confoundedly addressed the effect of sulfotanshinone sodium injection in the treatment of unstable angina. Results. Twenty-five studies involving 2,377 people were included. There was no evidence that sulfotanshinone sodium alone had better or worse effects to routine western medicine treatments in improving clinical symptoms (RR 1.00, 95% CI 0.90 to 1.11) and ECG (RR 0.97, 95% CI 0.87 to 1.09). However, there was evidence that sulfotanshinone sodium combined with western medications was a better treatment option than western medications alone in improving clinical symptoms (RR 1.28, 95% CI 1.23 to 1.3), ECG (RR 1.26, 95% CI 1.18 to 1.35), C-reaction protein (mean difference 2.10, 95% CI 1.63 to 2.58), and IL-6 (mean difference −3.85, 95% CI −4.10 to −3.60). There was no difference between sulfotanshinone sodium plus western medications and western medications alone affecting mortality (RR 0.50, 95% CI 0.02 to 12.13). Conclusion. Compared with western medications alone, sulfotanshinone sodium combined with western medications may provide more benefits for patients with unstable angina. Further large-scale high-quality trials are warranted

Anxiety, Loneliness, Drug Craving, and Depression Among Substance Abusers in Sichuan Province, China

Studies have reported that anxiety had a positive effect on depression among substance abusers in males. However, little is known about the mechanism underlying this relationship in substance abusers in males. The purpose of this study was to investigate the mediating effect of loneliness and drug craving between anxiety and depression in substance abusers in males. State-Trait Anxiety Inventory, The UCLA Loneliness Scale, Drug Craving Scale, and The Center for Epidemiologic Studies Depression Scale were employed into this study to investigate 585 substance abusers in males (age range of 20-58 years: M = 33.21, SD = 6.97). Structural equation modeling and the bootstrap approach were used to analyze the mediating effect of loneliness and drug craving on the relationship between anxiety and depression. The results indicated that: Loneliness had a significant positive correlation with anxiety (r = 0.37, p < 0.001) and depression (r = 0.49, p < 0.001);Drug craving had a significant positive correlation with anxiety (r = 0.28, p < 0.001) and depression (r = 0.39, p < 0.001). Loneliness and drug craving mediated the link between anxiety and depression. There was a significant positive correlation between substance abusers in male's anxiety, loneliness, drug craving, and depression. Loneliness and drug craving had a significant mediating effect on the relationship between anxiety and depression. Therefore, it was suggested that substance abusers in male's anxiety and depression might be improved and driven by decreasing loneliness and drug craving. Targeted interventions to decrease substance abusers in male's loneliness and drug craving should be developed, implemented, and help them to recover

H∞ model reduction for discrete-time Markovian jump systems with deficient mode information

This paper investigates the problem of H∞ model reduction for a class of discrete-time Markovian jump linear systems (MJLSs) with deficient mode information, which simultaneously involves the exactly known, partially unknown, and uncertain transition probabilities. By fully utilizing the properties of the transition probability matrices, together with the convexification of uncertain domains, a new H∞ performance analysis criterion for the underlying MJLSs is first derived, and then two approaches, namely, the convex linearisation approach and iterative approach, for the H∞ model reduction synthesis are proposed. Finally, a simulation example is provided to illustrate the effectiveness of the proposed design methods