SoK: Computer-Aided Cryptography

Computer-aided cryptography is an active area of research that develops and applies formal, machine-checkable approaches to the design, analysis, and implementation of cryptography. We present a cross-cutting systematization of the computer-aided cryptography literature, focusing on three main areas: (i) design-level security (both symbolic security and computational security), (ii) functional correctness and efficiency,and (iii) implementation-level security (with a focus on digital side-channel resistance). In each area, we first clarify the role of computer-aided cryptography—how it can help and what the caveats are—in addressing current challenges. We next present a taxonomy of state-of-the-art tools, comparing their accuracy,scope, trustworthiness, and usability. Then, we highlight their main achievements, trade-offs, and research challenges. After covering the three main areas, we present two case studies. First, we study efforts in combining tools focused on different areas to consolidate the guarantees they can provide. Second, we distill the lessons learned from the computer-aided cryptography community’s involvement in the TLS 1.3 standardization effort.Finally, we conclude with recommendations to paper authors,tool developers, and standardization bodies moving forward

IronFleet: Proving Practical Distributed Systems Correct

Abstract Distributed systems are notorious for harboring subtle bugs. Verification can, in principle, eliminate these bugs a priori, but verification has historically been difficult to apply at fullprogram scale, much less distributed-system scale. We describe a methodology for building practical and provably correct distributed systems based on a unique blend of TLA-style state-machine refinement and Hoare-logic verification. We demonstrate the methodology on a complex implementation of a Paxos-based replicated state machine library and a lease-based sharded key-value store. We prove that each obeys a concise safety specification, as well as desirable liveness requirements. Each implementation achieves performance competitive with a reference system. With our methodology and lessons learned, we aim to raise the standard for distributed systems from "tested" to "correct.&quot

Measurement of the Neutron Radius of 208Pb through Parity Violation in Electron Scattering

We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from Pb208. APV is sensitive to the radius of the neutron distribution (Rn). The result APV=0.656±0.060(stat)±0.014(syst)  ppm corresponds to a difference between the radii of the neutron and proton distributions Rn−Rp=0.33+0.16−0.18  fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.</p

New Precision Limit on the Strange Vector Form Factors of the Proton

<p>The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2=0.624  GeV2 and beam energy Eb=3.48  GeV to be APV=−23.80±0.78(stat)±0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors GsE+0.517GsM=0.003±0.010(stat)±0.004(syst)±0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.</p

New Measurements of the Transverse Beam Asymmetry for Elastic Electron Scattering from Selected Nuclei

<p>We have measured the beam-normal single-spin asymmetry An in the elastic scattering of 1–3 GeV transversely polarized electrons from H1 and for the first time from He4, C12, and Pb208. For H1, He4, and C12, the measurements are in agreement with calculations that relate An to the imaginary part of the two-photon exchange amplitude including inelastic intermediate states. Surprisingly, the Pb208 result is significantly smaller than the corresponding prediction using the same formalism. These results suggest that a systematic set of new Anmeasurements might emerge as a new and sensitive probe of the structure of heavy nuclei.</p