There are many advantages to voting schemes in which voters rank all candidates in order, rather than just choosing their favorite. However, these schemes inherently suffer from a coercion problem when there are many candidates, because a coercer can demand a certain permutation from a voter and then check whether that permutation appears during tallying. Recently developed cryptographic voting protocols allow anyone to audit an election (universal verifiability), but existing systems are either not applicable to ranked voting at all, or reveal enough information about the ballots to make voter coercion possible. We solve this problem for the popular single transferable vote (STV) ranked voting system, by constructing an algorithm for the verifiable tallying of encrypted votes. Our construction improves upon existing work because it extends to multiple-seat STV and reveals less information than other schemes. The protocol is based on verifiable shuffling of homomorphic encryptions, a well-studied primitive in the voting arena. Our protocol is efficient enough to be practical, even for a large election.

How do you tell a computer from a human? The situation arises often on the Internet, when online polls are conducted, accounts are requested, undesired email is received, and chat-rooms are spammed. The approach we use is to create a visual challenge that is easy for humans but difficult for a computer. More specifically, our challenge is to recognize a string of random distorted characters. To pass the challenge, the subject must type in the correct corresponding ASCII string. From an OCR point of view, this problem is interesting because our goal is to use the vast amount of accumulated knowledge to defeat the state of the art OCR algorithms. This is a role reversal from traditional OCR research. Unlike many other systems, our algorithm is based on the assumption that segmentation is much more difficult than recognition. Our image challenges present hard segmentation problems that humans are particularly apt at solving. The technology is currently being used in MSN's Hotmail registration system, where it has significantly reduced daily registration rate with minimal Consumer Support impact.

We describe the design of a Windows file-system directory service that ensures the persistence, integrity, privacy, syntactic legality, and case-insensitive uniqueness of the names it indexes. Byzantine state replication provides persistence and integrity, and encryption imparts privacy. To enforce Windows' baroque name syntax - including restrictions on allowable characters, on the terminal character, and on several specific names - we develop a cryptographic process, called "exclusive encryption," that inherently excludes syntactically illegal names and that enables the exclusion of case-insensitively duplicate names without access to their plaintext. This process excludes entire names by mapping the set of allowed strings to the set of all strings, excludes certain characters through an amended prefix encoding, excludes terminal characters through varying the prefix coding by character index, and supports case-insensitive comparison of names by extracting and encrypting case information separately. We also address the issues of hiding name-length information and access-authorization information, and we report a newly discovered problem with enforcing case-insensitive uniqueness for Unicode names.

Article Distributing the power of a government to enhance the privacy of voters Share on Authors: Josh C Benaloh Yale University Yale UniversityView Profile , Moti Yung Columbia University Columbia UniversityView Profile Authors Info & Claims PODC '86: Proceedings of the fifth annual ACM symposium on Principles of distributed computingNovember 1986 Pages 52–62https://doi.org/10.1145/10590.10595Online:01 November 1986Publication History 138citation559DownloadsMetricsTotal Citations138Total Downloads559Last 12 Months23Last 6 weeks5 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

This paper describes a cryptographic scheme for holding a secure secret ballot election in which all communication is public. Voters cast their votes electronically, suitably encrypted, and a “government” releases a tally and a proof of its correctness which can be verified by all.