Monthly Archives: November 2020

Three Paper Thursday: Vēnī, Vīdī, Vote-y – Election Security

Academic papers, Cryptology, Electronic voting, Open-source security, Security engineering, Three Paper Thursday, Useful software,

With the recent quadrennial instantiation of the US presidential election, discussions of election security have predictably resurged across much of the world. Indeed, news cycles in the US, UK, and EU abound with talking points surrounding the security of elections. In light of this context, we will use this week’s Three Paper Thursday to shed light on the technical challenges, solutions, and opportunities in designing secure election systems.

This post will focus on the technical security of election systems. That said, the topic of voter manipulation techniques such as disinformation campaigns, although out of scope here, is also an open area of research.

At first glance, voting may not seem like a challenging problem. If we are to consider a simple majority vote, surely a group of young schoolchildren could reach a consensus in minutes via hand-raising. Striving for more efficient vote tallying, though, perhaps we may opt to follow the IETF in consensus through humming. As we seek a solution that can scale to large numbers of voters, practical limitations will force us to select a multi-location, asynchronous process. Whether we choose in-person polling stations or mail-in voting, challenges quickly develop: how do we know a particular vote was counted, its contents kept secret, and the final tally correct?

National Academies of Sciences, Engineering, and Medicine (U.S.), Ed., Securing the vote: protecting American democracy, The National Academies Press (2018)

The first paper is particularly prominent due to its unified, no-nonsense, and thorough analysis. The report is specific to the United States, but its key themes apply generally. Written in response to accusations of international interference in the US 2016 presidential election, the National Academies provide 41 recommendations to strengthen the US election system.

These recommendations are extremely straightforward, and as such a reminder that adversaries most often penetrate large systems by targeting the “weakest link.” Among other things, the authors recommend creating standardized ballot data formats, regularly validating voter registration lists, evaluating the accessibility of ballot formats, ensuring access to absentee ballots, conducting appropriate audits, and providing adequate funding for elections.

It’s important to get the basics right. While there are many complex, stimulating proposals that utilize cutting-edge algorithms, cryptography, and distributed systems techniques to strengthen elections, many of these proposals are moot if the basic logistics are mishandled.

Some of these low-tech recommendations are, to the surprise of many passionate technologists, quite common among election security specialists. For example, requiring a paper ballot trail and avoiding internet voting based on current technology is also cited in our next paper.

Matthew Bernhard et al., Public Evidence from Secret Ballots, arXiv:1707.08619 (2017)

Governance aside, the second paper offers a comprehensive survey of the key technical challenges in election security and common tools used to solve them. The paper motivates the difficulty of election systems by attesting that all actors involved in an election are mutually distrustful, meaningful election results require evidence, and voters require ballot secrecy.

Ballot secrecy is more than a nicety; it is key to a properly functioning election system. Implemented correctly, ballot secrecy prevents voter coercion. If a voter’s ballot is not secret, or indeed if there is any way a voter can post-facto prove the casting a certain vote, malicious actors may pressure the voter to provide proof that they voted as directed. This can be insidiously difficult to prevent if not considered thoroughly.

Bernhard et al. discuss risk-limiting audits (RLAs) as an efficient yet powerful way to limit uncertainty in election results. By sampling and recounting a subset of votes, RLAs enable the use of statistical methods to increase confidence in a correct ballot count. Employed properly, RLAs can enable the high-probability validation of election tallies with effort inversely proportional to the expected margin. RLAs are now being used in real-world elections, and many RLA techniques exist in practice. 

Refreshingly, this paper establishes that blockchain-based voting is a bad idea. Blockchains inherently lack a central authority, so enforcing election rules would be a challenge. Furthermore, a computationally powerful adversary could control which votes get counted.

The paper also discusses high-level cryptographic tools that can be useful in elections. This leads us to our third and final paper.

Josh Benaloh, ElectionGuard Specification v0.95, Microsoft GitHub (2020)

Our final paper is slightly different from the others in this series; it’s a snapshot of a formal specification that is actively being developed, largely based on the author’s 1996 Yale doctoral thesis.

The specification describes ElectionGuard, a system being built by Microsoft to enable verifiable election results (disclaimer: the author of this post holds a Microsoft affiliation). It uses a combination of exponential ElGamal additively-homomorphic encryption, zero knowledge proofs, and Shamir’s secret sharing to conduct publicly-verifiable, secret-ballot elections.

When a voter casts a ballot, they are given a tracking code which can be used to verify the counting of the ballot’s votes via cryptographic proofs published with the final tally. Voters can achieve high confidence that their ballot represents a proper encryption of their desired votes by optionally spoiling an unlimited number of ballots – triggering a decryption of the spoiled ballot – at the time of voting. Encrypted ballots are homomorphically tallied in encrypted form by the election authorities, and the number of authorities that participate in tallying must meet the threshold set for the election to protect against malicious authorities.

The specification does not require that the system be used for exclusively internet-based or polling station-based elections; rather it is a framework for users to consume as they wish. Indeed, one of the draws to ElectionGuard is that it does not mandate a specific UI, ballot marking device, or even API. This flexibility allows election authorities to leverage the system in the manner that best fits their jurisdiction. The open source implementation can be found on GitHub.

There are many pieces of voting software available, but ElectionGuard is the new kid on the block that addresses many of the concerns raised in our earlier papers.

Key Themes

Designing secure election systems is difficult.

Often, election systems fall short on the basics; improper voting lists, postage issues, and poorly formatted ballots can disrupt elections as much as some adversaries. Ensuring that the foundational components of an election are handled well currently involves seemingly mundane – but important – things such as paper ballot trails, chains of custody, and voter ID verification.

High-tech election proposals are not new; indeed key insights into the use of cryptographic techniques in elections were being discussed in the academic literature well over two decades ago. That said, in recent years there has been an ostensibly increased investment in implementing cryptographic election systems, and although there remain many problems to be solved the future in this area looks promising.

Three Paper Thursday: Attacking Machine Vision Models In Real Life

Academic papers, Security engineering, Three Paper Thursday

This is a guest post by Alex Shepherd.

There is a growing body of research literature concerning the potential threat of physical-world adversarial attacks against machine-vision models. By applying adversarial perturbations to physical objects, machine-vision models may be vulnerable to images containing these perturbed objects, resulting in an increased risk of misclassification. The potential impacts could be significant and have been identified as risk areas for autonomous vehicles and military UAVs.

For this Three Paper Thursday, we examine the following papers exploring the potential threat of physical-world adversarial attacks, with a focus on the impact for autonomous vehicles.

Alexey Kurakin, Ian Goodfellow, and Samy Bengio. Adversarial examples in the physical world, arXiv:1607.02533 (2016)

In this seminal paper, Kurakin et al. report their findings of an experiment conducted using adversarial images taken from a phone camera as input for a pre-trained ImageNet Inceptionv3 image classification model. Methodology was based on a white-box threat model, with adversarial images crafted from the ImageNet validation dataset using the Inceptionv3 model.
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Three paper Thursday: Online Extremism and Radicalisation

Cybercrime, Three Paper Thursday,

With the recent United States presidential election, I have chosen to focus the theme of this Three Paper Thursday on extremism and radicalisation. This topic has got increasing media attention during the past six years in the United States, through both a general rise in the public prominence of far-right, racist rhetoric in political culture (often attributed to the Trump presidency), and a series of high-profile violent events associated with far-right extremism. These events range from the riots in Charlottesville, Virginia (which turned violent when rally attendees clashed with counter-protesters and a vehicle drove into a crowd marching through downtown, killing one protester (Heim, Silverman, Shapiro, & Brown, 2017), to the recent arrest of individuals plotting a kidnap of the Governor of Michigan. This far-right violence brought to light the continued existence of right-wing extremism in the United States. This has historical roots in well-known organisations such as the Ku Klux Klan (KKK), a secretive, racist, terrorist organisation founded in 1865 during Reconstruction as part of a backlash against the acquisition of civil rights by African-American people in the South (Bowman-Grieve, 2009; Martin, 2006).

In contemporary online societies, the landscape and dynamics of right-wing extremist communities have changed. These communities have learned how to exploit the capacities of online social networks for recruitment, information sharing, and community building. The sophistication and reach of online platforms has evolved rapidly from the bulletin board system (BBS) to online forums and now social media platforms, which incorporate powerful technologies for marketing, targeting, and disseminating information. However, the use of these platforms for right-wing radicalisation (the process through which an individual develops and/or accepts extreme ideologies and beliefs) remains under-examined in academic scholarship. This Three Paper Thursday pulls together some key current literature on radicalisation in online contexts.

Maura Conway, Determining the role of the internet in violent extremism and terrorism: Six suggestions for progressing research. Studies in Conflict & Terrorism, 40(1), 77-98. https://www.tandfonline.com/doi/full/10.1080/1057610X.2016.1157408.

The first paper comments on future directions for research in understanding and determining the role of the Internet in violent extremism and terrorism. After guiding readers through an overview of current research, the author argues that there is a lack of both descriptive and explanatory work on the topic, as the field remains divided. Some view Internet as mere speech platforms and argue that participation in online radicalised communities is often the most extreme behaviour in which most individuals engage. Others acknowledge the affordances of the Internet but are uncertain in its role in replacing or strengthening other radicalisation processes. The author concludes that two major research questions remain to be answered: whether radicalisation can occur in a purely online context, and if so, does it contribute to violence? In that case, the mechanisms merit further exploration. The author makes six suggestions for future researchers: a) widening current research to include movements beyond jihadism, b) conducting comparison research (e.g., between platforms and/or organisations), c) studying individual users in extremist communities and groups, d) using large-scale datasets, e) adopting an interdisciplinary approach, and f) examining the role of gender.

Yi Ting Chua, Understanding radicalization process in online far-right extremist forums using social influence model. PhD thesis, Michigan State University, 2019. Available from https://d.lib.msu.edu/etd/48077.

My doctoral dissertation examines the impact of participation in online far-right extremist groups on radicalisation. In this research, I applied social network analysis and integrated theories from criminology (social learning theory) and political science (the idea of the echo chamber) to understand the process of attitudinal changes within social networks. It draws on a longitudinal database of threads saved from eight online far-right extremist forums. With the social influence model, which is a regression model with a network factor, I was able to include the number of interactions and attitudinal beliefs of user pairs when examining attitudinal changes across time. This model allows us to determine if, and how, active interactions result in expression of more radical ideological beliefs. Findings suggested that online radicalisation occurred at varying degrees in six of seven forums, with a general lowered level of expressed extremism towards the end of observed time period. The study found strong support the proposition that active interactions with forum members and connectedness are predictors of radicalisation, while suggesting that other mechanisms, such as self-radicalisation and users’ prior beliefs, were also important. This research highlighted the need for theory integration, detailed measures of online peer association, and cross-platform comparisons (i.e. Telegram and Gab) to address the complex phenomena of online radicalisation.

Magdalena Wojcieszak, ‘Don’t talk to me’: effects of ideologically homogeneous online groups and politically dissimilar offline ties on extremism. New Media & Society, 12(4) (2010) pp 637-655. https://journals.sagepub.com/doi/abs/10.1177/1461444809342775.

In this article, the author is interested in answering two questions: 1) does participation in ideologically homogeneous online groups increase extreme beliefs, and 2) how do offline strong and weak ties with dissimilar beliefs affect extreme beliefs? The author uses online survey data and posts from neo-Nazi online forums. The outcome is measured by respondents’ responses to 10 ideology-specific statements. Other variables in the analysis included the level of participation in online groups, perceived dissimilarity of offline ties, news media exposure and demographics. Findings from a multivariate regression model indicate that participation in online groups was a strong predictor of support for racial violence after controlling for demographic factors and news media exposure. Forum members’ attitudes are subjected to normative influences via punitive or rewarding replies. For individuals with politically dissimilar offline ties, the author finds a weakened participation effect.

Together, these papers highlight the complexity of assessing the role played by the Internet in the radicalisation process. The first paper encourages researchers to tackle whether online violent radicalisation occurs via six different approaches. The other two papers show support for online radicalisation while simultaneously calling attention to the effect of other variables, such as the influence of offline relationships and users’ baseline beliefs prior to online participation. All of these papers cross academic disciplines, highlighting the importance of an interdisciplinary perspective.

References

Bowman-Grieve, L. (2009). Exploring “Stormfront”: A virtual community of the radical right. Studies in Conflict & Terrorism, 32(11), 989-1007.

Heim, J., Silverman, E., Shapiro, T. R., Brown, E. (2017, August 13). One dead as car strikes crowds amid protests of white nationalist gathering in Charlottesville; two police die in helicopter crash. The Washington Post. Retrieved from https://www.washingtonpost.com/local/fights-in-advance-of-saturday-protest-in-charlottesville/2017/08/12/155fb636-7f13-11e7-83c7-5bd5460f0d7e_story.html?utm_term=.33b6686c7838.

Martin, G. (2006). Understanding Terrorism: Challenges, Perspectives, and Issues. Thousand Oaks, California: Sage Publications.

SHB Seminar

Academic papers, Politics, Privacy technology, Security economics, Security psychology, Seminars

The SHB seminar on November 5th was kicked off by Tom Holt, who’s discovered a robust underground market in identity documents that are counterfeit or fraudulently obtained. He’s been scraping both websites and darkweb sites for data and analysing how people go about finding, procuring and using such credentials. Most vendors were single-person operators although many operate within affiliate programs; many transactions involved cryptocurrency; many involve generating pdfs that people can print at home and that are good enough for young people to drink alcohol. Curiously, open web products seem to cost twice as much as dark web products.

Next was Jack Hughes, who has been studying the contract system introduced by hackforums in 2018 and made mandatory the following year. This enabled him to analyse crime forum behaviour before and during the covid-19 era. How do new users become active, and build up trust? How does it evolve? He collected 200,000 transactions and analysed them. The contract mandate stifled growth quickly, leading to a first peak; covid caused a second. The market was already centralised, and became more so with the pandemic. However contracts are getting done faster, and the main activity is currency exchange: it seems to be working as a cash-out market.

Anita Lavorgna has been studying the discourse of groups who oppose public mask mandates. Like the antivaxx movement, this can draw in fringe groups and become a public-health issue. She collected 23654 tweets from February to June 2020. There’s a diverse range of voices from different places on the political spectrum but with a transversal theme of freedom from government interference. Groups seek strength in numbers and seek to ally into movements, leading to the mask becoming a symbol of political identity construction. Anita found very little interaction between the different groups: only 144 messages in total.

Simon Parkin has been working on how we can push back on bad behaviours online while they are linked with good behaviours that we wish to promote. Precision is hard as many of the desirable behaviours are not explicitly recognised as such, and as many behaviours arise as a combination of personal incentives and context. The best way forward is around usability engineering – making the desired behaviours easier.

Bruce Schneier was the final initial speaker, and his topic was covid apps. The initial rush of apps that arrived in March through June have known issues around false positives and false negatives. We’ve also used all sorts of other tools, such as analysis of Google maps to measure lockdown compliance. The third thing is the idea of an immunity passport, saying you’ve had the disease, or a vaccine. That will have the same issues as the fake IDs that Tom talked about. Finally, there’s compliance tracking, where your phone monitors you. The usual countermeasures apply: consent, minimisation, infosec, etc., though the trade-offs might be different for a while. A further bunch of issues concern home working and the larger attack surface that many firms have as a result of unfamiliar tools, less resistance to being tols to do things etc.

The discussion started on fake ID; Tom hasn’t yet done test purchases, and might look at fraudulently obtained documents in the future, as opposed to completely counterfeit ones. Is hackforums helping drug gangs turn paper into coin? This is not clear; more is around cashing out cybercrime rather than street crime. There followed discussion by Anita of how to analyse corpora of tweets, and the implications for policy in real life. Things are made more difficult by the fact that discussions drift off into other platforms we don’t monitor. Another topic was the interaction of fashion: where some people wear masks or not as a political statement, many more buy masks that get across a more targeted statement. Fashion is really powerful, and tends to be overlooked by people in our field. Usability research perhaps focuses too much on the utilitarian economics, and is a bit of a blunt instrument. Another example related to covid is the growing push for monitoring software on employees’ home computers. Unfortunately Uber and Lyft bought a referendum result that enables them to not treat their staff in California as employees, so the regulation of working hours at home will probably fall to the EU. Can we perhaps make some input into what that should look like? Another issue with the pandemic is the effect on information security markets: why should people buy corporate firewalls when their staff are all over the place? And to what extent will some of these changes be permanent, if people work from home more? Another thread of discussion was how the privacy properties of covid apps make it hard for people to make risk-management decisions. The apps appear ineffective because they were designed to do privacy rather than to do public health, in various subtle ways; giving people low-grade warnings which do not require any action appear to be an attempt to raise public awareness, like mask mandates, rather than an effective attempt to get exposed individuals to isolate. Apps that check people into venues have their own issues and appear to be largely security theatre. Security theatre comes into its own where the perceived risk is much greater than the actual risk; covid is the opposite. What can be done in this case? Targeted warnings? Humour? What might happen when fatigue sets in? People will compromise compliance to make their lives bearable. That can be managed to some extent in institutions like universities, but in society it will be harder. We ended up with the suggestion that the next SHB seminar should be in February, which should be the low point; after that we can look forward to things getting better, and hopefully to a meeting in person in Cambridge on June 3-4 2021.