Generalizing the SPDZ Compiler For Other Protocols

Protocols for secure multiparty computation (MPC) enable a set of mutually distrusting parties to compute an arbitrary function of their inputs while preserving basic security properties like \emph{privacy} and \emph{correctness}. The study of MPC was initiated in the 1980s where it was shown that any function can be securely computed, thus demonstrating the power of this notion. However, these proofs of feasibility were theoretical in nature and it is only recently that MPC protocols started to become efficient enough for use in practice. Today, we have protocols that can carry out large and complex computations in very reasonable time (and can even be very fast, depending on the computation and the setting). Despite this amazing progress, there is still a major obstacle to the adoption and use of MPC due to the huge expertise needed to design a specific MPC execution. In particular, the function to be computed needs to be represented as an appropriate Boolean or arithmetic circuit, and this requires very specific expertise. In order to overcome this, there has been considerable work on compilation of code to (typically) Boolean circuits. One work in this direction takes a different approach, and this is the SPDZ compiler (not to be confused with the SPDZ protocol) that takes high-level Python code and provides an MPC run-time environment for securely executing that code. The SPDZ compiler can deal with arithmetic and non-arithmetic operations and is extremely powerful. However, until now, the SPDZ compiler could only be used for the specific SPDZ family of protocols, making its general applicability and usefulness very limited. In this paper, we extend the SPDZ compiler so that it can work with general underlying protocols. Our SPDZ extensions were made in mind to enable the use of SPDZ for arbitrary protocols and to make it easy for others to integrate existing and new protocols. We integrated three different types of protocols, an honest-majority protocol for computing arithmetic circuits over a field (for any number of parties), a three-party honest majority protocol for computing arithmetic circuits over the ring of integers $\Z_{2^n}$, and the multiparty BMR protocol for computing Boolean circuits. We show that a single high-level SPDZ-Python program can be executed using all of these underlying protocols (as well as the original SPDZ protocol), thereby making SPDZ a true general run-time MPC environment. In order to be able to handle both arithmetic and non-arithmetic operations, the SPDZ compiler relies on conversions from field elements to bits and back. However, these conversions do not apply to ring elements (in particular, they require element division), and we therefore introduce new bit decomposition and recomposition protocols for the ring over integers with replicated secret sharing. These conversions are of independent interest and utilize the structure of $\Z_{2^n}$ (which is much more amenable to bit decomposition than prime-order fields), and are thus much more efficient than all previous methods. We demonstrate our compiler extensions by running a complex SQL query and a decision tree evaluation over all protocols

Rudimentary modeling of acceptability judgement from a large scale, unbiaseddata

Acceptability Rating Data for Japanese (ARDJ) is a project that explores the true nature of acceptability judgement basedon a large-scale survey using theoretically unbiased stimuli. Its main survey was carried out in 2018 in two phases withcarefully constructed 300 stimulus sentences: Phrase 1 was a smaller scale experiment with roughly 300 college students;Phase 2 was a large scale web survey with over 1,600 participants.This paper reports on phase 2 and provides two results: Analysis 1 brought us a good typology of 300 sentences; Analysis2 implements explicit modeling of acceptability judgement using Semi-supervised local Fisher discriminant analysis.The results, if combined, suggest that i) acceptability is not a simple dichotomous partitioning of stimuli; ii) acceptabilityis a complex property that emerges through an interplay among the three factors: 1) degree or strength of deviance, 2)syntactic and/or semantic complexity of stimulus, and 3) localizability of deviance

Do the benefits of sodium-glucose cotransporter 2 inhibitors exceed the risks in patients with type 1 diabetes?

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) are well-established means of improving glycemia and preventing cardio-renal events in patients with type 2 diabetes. However, their efficacy and safety have yet to be fully characterized in patients with type 1 diabetes (T1D). We studied patients with T1D who regularly attended one of five diabetes centers and treated with an SGLT2i (ipragliflozin or dapagliflozin) for 52 weeks, and the changes in HbA1c, body mass, insulin dose, and laboratory data were retrospectively evaluated and adverse events (AEs) recorded during December 2018 to April 2021. A total of 216 patients with T1D were enrolled during the period. Of these, 42 were excluded owing to short treatment periods and 15 discontinued their SGLT2i. The mean changes in glycated hemoglobin (HbA1c), body mass, and insulin dose were -0.4%, -2.1 kg, and -9.0%, respectively. The change in HbA1c was closely associated with the baseline HbA1c (p < 0.001), but not with the baseline body mass or renal function. The basal and bolus insulin doses decreased by 18.2% and 12.6%, respectively, in participants with a baseline HbA1c <8%. The most frequent AE was genital infection (2.8%), followed by diabetic ketoacidosis (DKA; 1.4%). None of the participants experienced severe hypoglycemic events. In conclusion, the administration of an SGLT2i in addition to intensive insulin treatment in patients with T1D improves glycemic control and body mass, without increasing the incidence of hypoglycemia or DKA

Spontaneous electrical and Ca2+ signals in typical and atypical smooth muscle cells and interstitial cell of Cajal-like cells of mouse renal pelvis

Electrical rhythmicity in the renal pelvis provides the fundamental drive for the peristaltic contractions that propel urine from the kidney to bladder for storage until micturition. Although atypical smooth muscles (ASMCs) within the most proximal regions of the renal pelvis have long been implicated as the pacemaker cells, the presence of a sparsely distributed population of rhythmically active Kit-positive interstitial cells of Cajal-like cells (ICC-LCs) have confounded our understanding of pelviureteric peristalsis. We have recorded the electrical activity and separately visualized changes in intracellular Ca2+ concentration in typical smooth muscle cells (TSMCs), ASMCs and ICC-LCs using intracellular microelectrodes and a fluorescent Ca2+ indicator, fluo-4. Nifedipine (1–10 μm)-sensitive driven action potentials and Ca2+ waves (frequency 6–15 min−1) propagated through the TSMC layer at a velocity of 1–2 mm s−1. High frequency (10–40 min−1) Ca2+ transients and spontaneous transient depolarizations (STDs) were recorded in ASMCs in the absence or presence of 1 μm nifedipine. ICC-LCs displayed low frequency (1–3 min−1) Ca2+ transients which we speculated arose from cells that displayed action potentials with long plateaus (2–5 s). Neither electrical activity propagated over distances > 50 μm. In 1 μm nifedipine, ASMCs or ICC-LCs separated by < 30 μm displayed some synchronicity in their Ca2+ transient discharge suggesting that they may well be acting as ‘point sources’ of excitation to the TSMC layer. We speculate that ASMCs act as the primary pacemaker in the renal pelvis while ICC-LCs play a supportive role, but can take over pacemaking in the absence of the proximal pacemaker drive