No Arabic abstract
Democratic principles demand that every voter should be able to individually verify that their vote is recorded as intended and counted as recorded, without having to trust any authorities. However, most end-to-end (E2E) verifiable voting protocols that provide universal verifiability and voter secrecy implicitly require to trust some authorities or auditors for the correctness guarantees that they provide. In this paper, we explore the notion of individual verifiability. We evaluate the existing E2E voting protocols and propose a new protocol that guarantees such verifiability without any trust requirements. Our construction depends on a novel vote commitment scheme to capture voter intent that allows voters to obtain a direct zero-knowledge proof of their vote being recorded as intended. We also ensure protection against spurious vote injection or deletion post eligibility verification, and polling-booth level community profiling.
Existing verifiable e-sortition systems are impractical due to computationally expensive verification (linear to the duration of the registration phase, T) or the ease of being denial of service. Based on the advance in verifiable delay functions, we propose a verifiable e-sortition scheme whose result can be efficiently verified in constant time with respect to T. We present the preliminary design and implementation, and explore future directions to further enhance practicability.
E-voting systems are a powerful technology for improving democracy. Unfortunately, prior voting systems have single points-of-failure, which may compromise availability, privacy, or integrity of the election results. We present the design, implementation, security analysis, and evaluation of the D-DEMOS suite of distributed, privacy-preserving, and end-to-end verifiable e-voting systems. We present two systems: one asynchronous and one with minimal timing assumptions but better performance. Our systems include a distributed vote collection subsystem that does not require cryptographic operations on behalf of the voter. We also include a distributed, replicated and fault-tolerant Bulletin Board component, that stores all necessary election-related information, and allows any party to read and verify the complete election process. Finally, we incorporate trustees, who control result production while guaranteeing privacy and end-to-end-verifiability as long as their strong majority is honest. Our suite of e-voting systems are the first whose voting operation is human verifiable, i.e., a voter can vote over the web, even when her web client stack is potentially unsafe, without sacrificing her privacy, and still be assured her vote was recorded as cast. Additionally, a voter can outsource election auditing to third parties, still without sacrificing privacy. We provide a model and security analysis of the systems, implement complete prototypes, measure their performance experimentally, and demonstrate their ability to handle large-scale elections. Finally, we demonstrate the performance trade-offs between the t
Voting is a means to agree on a collective decision based on available choices (e.g., candidates), where participants (voters) agree to abide by their outcome. To improve some features of e-voting, decentralized solutions based on a blockchain can be employed, where the blockchain represents a public bulletin board that in contrast to a centralized bulletin board provides $100%$ availability and censorship resistance. A blockchain ensures that all entities in the voting system have the same view of the actions made by others due to its immutable and append-only log. The existing blockchain-based boardroom voting solution called Open Voting Network (OVN) provides the privacy of votes and perfect ballot secrecy, but it supports only two candidates. We present BBB-Voting, an equivalent blockchain-based approach for decentralized voting than OVN, but in contrast to it, BBB-Voting supports 1-out-of-$k$ choices and provides a fault tolerance mechanism that enables recovery from stalling participants. We provide a cost-optimized implementation using Ethereum, which we compare with OVN and show that our work decreases the costs for voters by $13.5%$ in terms of gas consumption. Next, we outline the extension of our implementation scaling to magnitudes higher number of participants than in a boardroom voting, while preserving the costs paid by the authority and participants -- we made proof-of-concept experiments with up to 1000 participants.
This section shows an overview of a recent development of the studies on great space weather events in history. Its discussion starts from the Carrington event and compare its intensity with the extreme storms within the coverage of the regular magnetic measurements. Extending its analyses back beyond their onset, this section shows several case studies of extreme storms with sunspot records in the telescopic observations and candidate auroral records in historical records. Before the onset of telescopic observations, this section shows the chronological coverages of the records of unaided-eye sunspot and candidate aurorae and several case studies on their basis.
Concept bottleneck models map from raw inputs to concepts, and then from concepts to targets. Such models aim to incorporate pre-specified, high-level concepts into the learning procedure, and have been motivated to meet three desiderata: interpretability, predictability, and intervenability. However, we find that concept bottleneck models struggle to meet these goals. Using post hoc interpretability methods, we demonstrate that concepts do not correspond to anything semantically meaningful in input space, thus calling into question the usefulness of concept bottleneck models in their current form.