4,409 research outputs found

    Is Internet Voting Trustworthy? The Science and the Policy Battles

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    According to clear scientific consensus, no known technology can make internet voting secure. In some applications—such as e-pollbooks (voter sign-in), voter registration, and absentee ballot request—it is appropriate to use the internet, as the inherent insecurity can be mitigated by other means. But the insecurity of paperless transmission of a voted ballot through the internet cannot be mitigated. The law recognizes this in several ways. Courts have enjoined the use of certain paperless or internet-connected voting systems. Federal law requires states to allow voters to use the internet to request absentee ballots but carefully stops short of internet ballot return (i.e., voting). But many U.S. states and a few countries go beyond what is safe: they have adopted internet voting for citizens living abroad and (in some cases) for voters with disabilities. Most internet voting systems have an essentially common architecture, and they are insecure at least at the same key point: after the voter has reviewed the ballot but before it is transmitted. I review six internet voting systems deployed between 2006 and 2021 that were insecure in practice, just as predicted by theory—of which some were also insecure in surprising new ways, “unforced errors”. We cannot get along without the assistance of computers. U.S. ballots are too long to count entirely by hand unless the special circumstances of a recount require it. So computer-counted paper ballots play a critical role in the security and auditability of our elections. But audits cannot be used to secure internet voting systems, which have no paper ballots that form an auditable paper trail. There are policy controversies: trustworthiness versus convenience, and security versus accessibility. From 2019 to 2022 there were lawsuits in Virginia, New Jersey, New York, New Hampshire, and North Carolina; legislation enacted in Rhode Island and withdrawn in California. There is a common pattern to these disputes, which have mostly resolved in a way that provides remote accessible vote by mail (RAVBM) but stops short of permitting electronic ballot return (internet voting). What would it take to thoroughly review a proposed internet voting system to be assured whether it delivers the security it promises? Switzerland provides a case study. In Switzerland, after a few years of internet voting pilot projects, the Federal Chancellery commissioned several extremely thorough expert studies of their deployed system. These reports teach us not only about their internet voting system itself but about how to study those systems before making policy decisions. Accessibility of election systems to voters with disabilities is a genuine problem. Disability-rights groups have been among those lobbying for internet voting (which is not securable) and other forms of remote accessible vote by mail (which can be adequately securable). I review statistics showing that internet voting is probably not the most effective way to serve voters with disabilities

    Reformulation of the Stochastic Potential Switching Algorithm and a Generalized Fourtuin-Kasteleyn Representation

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    A new formulation of the stochastic potential switching algorithm is presented. This reformulation naturally leads us to a generalized Fourtuin-Kasteleyn representation of the partition function Z. A formula for internal energy E and that of heat capacity C are derived from derivatives of the partition function. We also derive a formula for the exchange probability in the replica exchange Monte Carlo method. By combining the formulae with the Stochastic Cutoff method, we can greatly reduce the computational time to perform internal energy and heat capacity measurements and the replica exchange Monte Carlo method in long-range interacting systems. Numerical simulations in three dimensional magnetic dipolar systems show the validity and efficiency of the method.Comment: 11 pages, 6 figures, to appear in PR

    Bose-Einstein condensation of alkaline earth atoms: 40^{40}{Ca}

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    We have achieved Bose-Einstein condensation of 40^{40}Ca, the first for an alkaline earth element. The influence of elastic and inelastic collisions associated with the large ground state s-wave scattering length of 40^{40}Ca was measured. From these findings, an optimized loading and cooling scheme was developed that allowed us to condense about 21042 \cdot 10^4 atoms after laser cooling in a two-stage magneto-optical trap and subsequent forced evaporation in a crossed dipole trap within less than 3 s. The condensation of an alkaline earth element opens novel opportunities for precision measurements on the narrow intercombination lines as well as investigations of molecular states at the 1^1S--3^3P asymptotes

    Effect of buffer on heparin binding and sensing in competitive aqueous media

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    Although buffer-specific effects on molecular recognition are known in biological science, they remain rare in supramolecular chemistry. The binding between a cationic dye, Mallard Blue (MalB), and polyanionic heparin in aqueous NaCl (150 mM) is studied in three commonly-used buffers (Tris-HCl, HEPES, Phosphate, each 10 mM). Although MalB has a very similar UV-Vis spectrum in each buffer, the sensory response towards heparin was different in each case. This can be ascribed to differences in the complex formed. In Tris-HCl which has the least competitive chloride counter-anions, MalB exhibits a hypsochromic shift of 25 nm, assigned to strong binding and aggregation of the dye on heparin. In more competitive HEPES, containing a sulfonate anion, there is weaker binding and less aggregation of MalB along the heparin; the hypsochromic shift is only 15 nm. In phosphate buffer, MalB can interact quite strongly with buffer phosphate anions; although heparin binding is still observed, the hypsochromic shift associated with dye aggregation is only 5 nm. As such, specific buffer interactions with the MalB-heparin complex mediate host-guest binding and sensing. Buffer choice must be made carefully in studies of molecular recognition – we would caution against using phosphate and sulfonate containing buffers when studying electrostatic binding

    Surprises in the suddenly-expanded infinite well

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    I study the time-evolution of a particle prepared in the ground state of an infinite well after the latter is suddenly expanded. It turns out that the probability density Ψ(x,t)2|\Psi(x, t)|^{2} shows up quite a surprising behaviour: for definite times, {\it plateaux} appear for which Ψ(x,t)2|\Psi(x, t)|^{2} is constant on finite intervals for xx. Elements of theoretical explanation are given by analyzing the singular component of the second derivative xxΨ(x,t)\partial_{xx}\Psi(x, t). Analytical closed expressions are obtained for some specific times, which easily allow to show that, at these times, the density organizes itself into regular patterns provided the size of the box in large enough; more, above some critical time-dependent size, the density patterns are independent of the expansion parameter. It is seen how the density at these times simply results from a construction game with definite rules acting on the pieces of the initial density.Comment: 24 pages, 14 figure
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