A framework for comparing the security of voting schemes

We present a new framework to evaluate the security of voting schemes. We utilize the framework to compare a wide range of voting schemes, including practical schemes in realworld use and academic schemes with interesting theoretical properties. In the end we present our results in a neat comparison table. We strive to be unambiguous: we specify our threat model, assumptions and scope, we give definitions to the terms that we use, we explain every conclusion that we draw, and we make an effort to describe complex ideas in as simple terms as possible. We attempt to consolidate all important security properties from literature into a coherent framework. These properties are intended to curtail vote-buying and coercion, promote verifiability and dispute resolution, and prevent denial-of-service attacks. Our framework may be considered novel in that trust assumptions are an output of the framework, not an input. This means that our framework answers questions such as ”how many authorities have to collude in order to violate ballot secrecy in the Finnish paper voting scheme?

Blockchain, consensus, and cryptography in electronic voting

Motivated by the recent trends to conduct electronic elections using blockchain technologies, we review the vast literature on cryptographic voting and assess the status of the field. We analyze the security requirements for voting systems and describe the major ideas behind the most influential cryptographic protocols for electronic voting. We focus on the great importance of consensus in the elimination of trusted third parties. Finally, we examine whether recent blockchain innovations can satisfy the strict requirements set for the security of electronic voting

Sixth International Joint Conference on Electronic Voting E-Vote-ID 2021. 5-8 October 2021

This volume contains papers presented at E-Vote-ID 2021, the Sixth International Joint Conference on Electronic Voting, held during October 5-8, 2021. Due to the extraordinary situation provoked by Covid-19 Pandemic, the conference is held online for second consecutive edition, instead of in the traditional venue in Bregenz, Austria. E-Vote-ID Conference resulted from the merging of EVOTE and Vote-ID and counting up to 17 years since the _rst E-Vote conference in Austria. Since that conference in 2004, over 1000 experts have attended the venue, including scholars, practitioners, authorities, electoral managers, vendors, and PhD Students. The conference collected the most relevant debates on the development of Electronic Voting, from aspects relating to security and usability through to practical experiences and applications of voting systems, also including legal, social or political aspects, amongst others; turning out to be an important global referent in relation to this issue. Also, this year, the conference consisted of: · Security, Usability and Technical Issues Track · Administrative, Legal, Political and Social Issues Track · Election and Practical Experiences Track · PhD Colloquium, Poster and Demo Session on the day before the conference E-VOTE-ID 2021 received 49 submissions, being, each of them, reviewed by 3 to 5 program committee members, using a double blind review process. As a result, 27 papers were accepted for its presentation in the conference. The selected papers cover a wide range of topics connected with electronic voting, including experiences and revisions of the real uses of E-voting systems and corresponding processes in elections. We would also like to thank the German Informatics Society (Gesellschaft für Informatik) with its ECOM working group and KASTEL for their partnership over many years. Further we would like to thank the Swiss Federal Chancellery and the Regional Government of Vorarlberg for their kind support. EVote- ID 2021 conference is kindly supported through European Union's Horizon 2020 projects ECEPS (grant agreement 857622) and mGov4EU (grant agreement 959072). Special thanks go to the members of the international program committee for their hard work in reviewing, discussing, and shepherding papers. They ensured the high quality of these proceedings with their knowledge and experience

Individual verifiability in electronic voting

This PhD Thesis is the fruit of the job of the author as a researcher at Scytl Secure Electronic Voting, as well as the collaboration with Paz Morillo, from the Department of Applied Mathematics at UPC and Alex Escala, PhD student. In her job at Scytl, the author has participated in several electronic voting projects for national-level binding elections in different countries. The participation of the author covered from the protocol design phase, to the implementation phase by providing support to the development teams. The thesis focuses on studying the mechanisms that can be provided to the voters, in order to examine and verify the processes executed in a remote electronic voting system. This work has been done as part of the tasks of the author at the electronic voting company Scytl. Although this thesis does not talk about system implementations, which are interesting by themselves, it is indeed focused on protocols which have had, or may have, an application in the real world. Therefore, it may surprise the reader by not using state of the art cryptography such as pairings or lattices, which still, although providing very interesting properties, cannot be efficiently implemented and used in a real system. Otherwise, the protocols presented in this thesis use standard and well-known cryptographic primitives, while providing new functionalities that can be applied in nowadays electronic voting systems. The thesis has the following contents: A survey on electronic voting systems which provide voter verification functionalities. Among these systems we can find the one used in the Municipal and Parliamentary Norwegian elections of 2011 and 2013, and the system used in the Australian State of New South Wales for the General State Elections in 2015, in which the author has had an active participation in the design of their electronic voting protocols. A syntax which can be used for modeling electronic voting systems providing voter verifiability. This syntax is focused on systems characterized by the voter confirming the casting of her vote, after verifying some evidences provided by the protocol. Along with this syntax, definitions for the security properties required for such schemes are provided. A description of the electronic voting protocol and system which has been used in 2014 and 2015 elections in the Swiss Canton of Neuchâtel, which has individual verification functionalities, is also provided in this thesis, together with a formal analysis of the security properties of the scheme and further extensions of the protocol. Finally, two new protocols which provide new functionalities respect to those from the state of the art are proposed: A new protocol providing individual verifiability which allows voters to defend against coertion by generating fake proofs, and a protocol which makes a twist to individual verifiability by ensuring that all the processes executed by the voting device and the remote server are correct, without requiring an active verification from the voter. A formal analysis of the security properties of both protocols is provided, together with examples of implementation in real systems.Aquesta tesi és fruit de la feina de l'autora com a personal de recerca a la empresa Scytl Secure Electtronic Voting, així com de la col·laboració amb la Paz Morillo, del departament de matemàtica aplicada a la UPC, i el Alex Escala, estudiant de doctorat. A la feina a Scytl, l'autora ha participat a varis projectes de vot electrònic per a eleccions vinculants a nivell nacional, que s'han efectuat a varis països. La participació de la autora ha cobert tant la fase de disseny del protocol, com la fase de implementació, on ha proveït suport als equips de desenvolupament. La tesi estudia els mecanismes que es poden proporcionar als votants per a poder examinar i verificar els processos que s'executen en sistemes de vot electrònic. Tot i que la tesi no parla de la implementació dels sistemes de vot electrònic, sí que s'enfoca en protocols que han tingut, o poden tenir, una aplicació pràctica actualment. La tesi té els continguts següents: Un estudi en sistemes de vot electrònic que proporcionen funcionalitats per a que els votants verifiquin els processos. Entre aquests sistemes, trobem el que es va utilitzar a les eleccions municipals i parlamentàries a Noruega als anys 2011 i 2013, així com el sistema utilitzat a l'estat Australià de New South Wales, per a les eleccions generals de 2015, sistemes en els que l'autora ha participat directament en el diseny dels seus protocols criptogràfics. La tesi també conté una sintaxi que es pot utilizar per modelar sistemes de vot electrònic que proporcionen verificabilitat individual (on verifica el votant). Aquesta sintaxi s'enfoca en sistemes caracteritzats pel fet de que el votant confirma la emissió del seu vot un cop ha verificat unes evidències sobre ell, proporcionades pel protocol. A més de la sintaxi, es proporcionen definicions de les propietats de seguretat d'aquestts sistemes. La tesi també conté una descripció del sistema i protocol de vot electrònic que s'utilitza al cantó Suís de Neuchâtel a partir del 2014, el qual té funcionalitats per a que els votants verifiquin certs processos del sistema. La tesi a més conté un anàlisi de la seguretat de l'esquema, així com possibles extensions del protocol. Finalment, la tesi inclou dos protocols nous que proporcionen noves característiques i funcionalitats respecte als existents a l'estat de l'art de la tècnica. El primer permet a un votant defendre's de un coaccionador generant proves falses, i el segon fa un canvi de paradigma de la verificabilitat individual, de forma que el votant no ha de verificar certs processos per a saber que s'han efectuant correctament. La tesi inclou un anàlisi formal de les propietats de seguretat dels dos protocols, així com exemples de com podrien ser implementats en un escenari real.Postprint (published version