Department of Computer Science and Technology

Security Group

2021 seminars

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04 May 14:00FastPay: High-Performance Byzantine Fault Tolerant Settlement / Alberto Sonnino, UCL

Webinar

FastPay allows a set of distributed authorities, some of which are Byzantine, to maintain a high-integrity and availability settlement system for pre-funded payments. It can be used to settle payments in a native unit of value (cryptocurrency), or as a financial side-infrastructure to support retail payments in fiat currencies. FastPay is based on Byzantine Consistent Broadcast as its core primitive, foregoing the expenses of full atomic commit channels (consensus). The resulting system has low-latency for both confirmation and payment finality. Remarkably, each authority can be sharded across many machines to allow unbounded horizontal scalability. Our experiments demonstrate intra-continental confirmation latency of less than 100ms, making FastPay applicable to point of sale payments. In laboratory environments, we achieve over 80,000 transactions per second with 20 authorities---surpassing the requirements of current retail card payment networks, while significantly increasing their robustness.

RECORDING : Please note, this event will be recorded and will be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

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27 April 14:00Mix-net cryptoeconomics: Rebooting privacy-preserving communications as incentive-driven collaborative projects / Aggelos Kiayias, University of Edinburgh

Webinar - link in abstract

Applying cryptographic operations in a distributed and collaborative fashion
has been for more than four decades a dominant paradigm in the design
of privacy-preserving communications systems and specifically mix-nets. The
design of such systems present to the end user a guarantee that typically
involves a threshold condition. For instance, such condition could have the form
"as long as x out of a certain set of y cryptographic keys remain
uncompromised then privacy is maintained.” Enforcing the condition
is typically out of scope for the system design and the end-user
has no tools whatsoever to assess whether the condition holds. As a result,
it is typically taken at face value. This is unfortunate as it may lead
to deployments where privacy fails - and to make matters worse,
no-one may even be aware of it.

In this talk, I will present ongoing work (in collaboration with
Claudia Diaz and Harry Halpin) that is pursued in the context of
Nym (https://nymtech.net/), an incentivised mix-network system.
The design is based on new techniques in the context of mix-nets
as well as it suitably adapts concepts first developed in the context
of blockchain protocols, and offers an incentive-driven privacy
preserving communication infrastructure that aims to provide privacy via
a novel "cryptoeconomic” mechanism.


RECORDING : Please note, this event will be recorded and will be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

Zoom Link: https://us02web.zoom.us/j/84294385634?pwd=NGovR0o2WFBvOU9nSlRpVUk4dWdRQT09

Meeting ID: 842 9438 5634
Passcode: 367447

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23 March 14:00Dark web marketplaces and COVID-19: Flexible and resilient / Andrea Baronchelli, City University of London and The Alan Turing Institute

Webinar

This talk focuses on two aspects of dark web marketplaces (DWMs). (1) It investigates how DWMs reacted to COVID-19. The analysis of millions of listings from 102 DWMs identified 788 listings directly related to COVID-19 products and monitor the temporal evolution of product categories including Personal Protective Equipment (PPE), medicines (e.g., hydroxyclorochine), and medical frauds, as well as 33 vaccine listings. In general supply of COVID-19 related goods on DWMs reacts either to shortages in the economy or to public attention, and in particular to misinformation. (2) It clarifies how the DWM ecosystem can be resilient despite the intrinsic weaknesses of individual markets. It analyses 24 separate episodes of unexpected marketplace closure by inspecting 133 million Bitcoin transactions among 38 million users, focusing on “migrating users” who move their trading activity to a different marketplace after a closure. It shows that most migrating users continue their trading activity on a single coexisting marketplace, typically the one with the highest trading volume. User migration is swift and trading volumes of migrating users recover quickly. Thus, although individual marketplaces might appear fragile, coordinated user migration guarantees overall systemic resilience.

REFERENCES
* Dark Web Marketplaces and COVID-19: Before the vaccine. EPJ Data Science 10 (1), 6 (2021)
* Dark Web Marketplaces and COVID-19: The vaccines. Preprint arXiv:2102.05470 (2021)
* Collective dynamics of dark web marketplaces. Scientific Reports 10 (1), 1-8 (2020).


RECORDING : Please note, this event will be recorded and will be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

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16 March 14:00Understanding Modern Phishing / Brad Wardman and Adam Oest, PayPal

Webinar

Despite ubiquitous anti-phishing technologies in modern computer systems and extensive mitigation efforts by the security ecosystem, large-scale phishing remains a key threat to Internet users. In this talk, we will explore the current state of phishing attacks to illustrate how criminals operate and better understand the many weaknesses exploited by their attacks. Through the lens of recent anti-phishing research---including a study of how the current pandemic has transformed phishing---we will also discuss future opportunities for better protecting users from phishing and related scams.

RECORDING : Please note, this event will be recorded and will be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

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09 March 14:00Deep Learning Assisted Side-Channel Attacks / Elena Dubrova, KTH Royal Institute of Technology

Webinar

Technologies such as deep learning are expected to be the cornerstones of tomorrow's cyber defenses. However, the adversaries are working just as hard as everyone else to turn these technologies to their advantage. In this talk, we will show how deep learning assisted side-channel attacks enable the attacker to break software implementations of Advanced Encryption Standard in USIM cards and Nordic Semiconductor's nRF52832 system-on-chip. We will also present our latest results on power analysis of an ARM Cortex-M4 first-order masked implementation of the Saber key encapsulation mechanism (third round finalist of the NIST post-quantum cryptography standardization process).

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02 March 14:00Crowdsourcing Security Research: A case study of AdObserver / Laura Edelson and Damon McCoy, New York University

Webinar

In the spring of 2020, we published AdObserver, a browser extension for anonymously crowdsourcing data about ads on social media. Over the past year, 17,000 users have downloaded AdObserver for Chrome or Firefox. During the 2020 US election period, we were able to collect observations of tens of thousands of ads every day. We publicly released the political Facebook ads we were able to identify, including the ad targetings. We present a case study of AdObserver and review initial results. Data collected via our browser extension has been instrumental to our discovery of security vulnerabilities and errors in both Facebook and Google’s systems for ensuring ads comply with platform policies and the law.

We also discuss important considerations for researchers considering collecting data in this way and specific best practices for projects attempting to use browser extensions to crowdsource data while protecting the privacy of users who donate data.

RECORDING : Please note, this event may be recorded and may be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

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23 February 14:00Dmitry goes to Hollywood: Criminal Excellence in (Cyber) La La Land / Luca Allodi, Eindhoven University of Technology

Webinar

Cyber-criminals and attackers at large have access to a wide range of technologies and techniques of varying sophistication to deliver attacks: from script-kiddie types of attacks employing automated and well-known exploits, to mature malware delivery platforms capable of crypting or packing malware at delivery time, and multi-stage, highly tailored social engineering attacks employing a large portfolio of targeting and psychological techniques. Yet, most cyber-criminal ventures are relatively un-interesting: dozens of underground market places exists, but which of those support technological innovation rather than mainly scam-for-scammers activities is currently hard to know. Similarly, yet another "Your mailbox is full, please click here to reset your password" phishing attack hardly makes the news, while we lack the tools to characterize much more sophisticated and innovative social engineering attacks targeting, for example, specific individuals across multiple attack stages.

In this talk we discuss what features characterize "cyber-criminal excellence", and distinguish it from "ordinary" Internet crime. Reflecting current attack trends, we focus on criminal markets and social engineering techniques: within both domains, we propose and discuss models and criteria to characterize relevant and highly innovative criminal ventures and sophisticated social engineering attacks which ought to be studied and understood, and showcase their application through real-world case studies.

RECORDING : Please note, this event will be recorded and will be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

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16 February 14:00A Liar and a Copycat: Nonverbal Coordination Increases with Lie Difficulty / Sophie van der Zee, Erasmus University Rotterdam

Webinar

Nonverbal coordination is the tendency to imitate the behaviors of others. Coordination can take place both on a conscious and a more unconscious or automatic level. How much people coordinate with their interaction partner, depends on several factors, including liking and common goals. There is some evidence that the coordination occurrence is also affected by cognitive load. So far, this has only been demonstrated in isolated body part movement. A forensically relevant setting that is strongly associated with increased cognitive load is deception. Lying, especially when fabricating accounts, can be more cognitively demanding than truth telling. In two studies, we demonstrate that interactional nonverbal coordination increases under the cognitive load of lying. Nonverbal coordination is an especially interesting cue to deceit because its occurrence relies on automatic processes and is therefore more difficult to deliberately control. Our findings complement current deception research into the liar’s nonverbal behavior by explicitly considering the interaction with the interviewer. Our findings extent the current literature on increased reliance on automated processes by demonstrating that nonverbal coordination can be such an automated process that is affected by increased cognitive load. The use of motion capture technology provides a novel, objective and efficient means of measurement.

RECORDING : Please note, this event will be recorded and will be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

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09 February 14:00Cybersecurity Risk to Hospitals from Building Services / Sheryn Gillin, University of Cambridge

Webinar

Human error and the vulnerability of clinical devices are perceived as the foremost cybersecurity risks in the critical infrastructure sector of Healthcare; this limited view, however, overlooks the possible disruption due to a malicious actor accessing the network or systems that maintain the environmental conditions within a healthcare facility. Operating theatres, laboratories, pharmacies, sterile stores and imaging equipment have stringent environmental requirements. To achieve these conditions, chilled water and ventilation must function within set tolerances; any divergence could significantly impact a hospital due to cancelled surgeries or diagnostic procedures, an MRI quench or the need to dispose of sterile products. Focussing on the systems required to maintain the environment within these specialist rooms, the vulnerabilities, threats, risks and impacts were investigated using based on four case study hospitals in Canada and the UK.

RECORDING : Please note, this event will be recorded and will be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.

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26 January 16:00Towards Provable Physical Safety Against False Actuation Attacks in CPS / Alvaro Cardenas, University of California, Santa Cruz

Webinar

The vulnerability of cyber-physical systems (CPS) is a growing area of concern, and in the past decade, researchers have proposed a variety of security defenses for these systems. Most of these proposals are heuristic in nature, and while they increase the protection of their target, the security guarantees they provide are unclear. In this talk we discuss two different approaches for modeling the security guarantees of a cyber-physical system against arbitrary false command attacks. The first part of the talk discusses the idea of providing physical protections by saturating actuators, and the second part of the talk discusses how to use barrier certificates to prove safety of a real-world system. Our work is an effort to move forward CPS security research towards precise definitions, precise claims, and provable security.

RECORDING : Please note, this event may be recorded and may be available after the event for an indeterminate period under a CC BY -NC-ND license. Audience members should bear this in mind before joining the webinar or asking questions.