Internship Talk: Bringing private SCT auditing into practice

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Abstract

PhD student Lena Heimberger visited Cloudflare in Lisbon from July to October. Now that she is back, she will talk about Transparency, the Certificate ecosystem, Merkle Tree Certificates, fallback strategies, protocols and why Portugese coffee culture is better than Italian. More concretely, she studied the certificate ecosystem in the context of post-quantum certificates, trying to sketch the design space for fallback mechanisms for so-called slow-issuance certificates. The result is an upper bound for fallback probabilities that can be used to study methods for fallbacks. As a part of this study, Lena and her colleagues found that SCT auditing is on the brink of being practical when using Private Information Retrieval methods.

Parts of the talk have already been presented at transparency.dev in London last month, and will be submitted in form of a paper soon.

The talk is aimed at Master’s students, but anybody is welcome. Questions, also about the internship, are explicitly encouraged.

 

Automatically Uncovering Hardware Side-Channels in Processor RTL with Multi-μPATH Synthesis

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Abstract

Modern hardware side-channel defenses are designed with respect to microarchitectural leakage contracts, which characterize microarchitectures’ hardware side-channels. Numerous leakage contracts have been proposed in the literature and by industry (e.g., Arm DIT, Intel DOIT, RISC-V Zkt) to support a variety of hardware side-channel defenses, implemented in hardware or software. Yet, no automated nor scalable approach exists for formally verifying hardware adherence to any of them.

In this talk, I will present SynthLC, an automated approach/tool for synthesizing (“uncovering”) a variety of formally verified leakage contracts — which collectively support ten state-of-the-art hardware side-channel defense — from a SystemVerilog processor design, assuming an attacker that monitors program execution time or resource contention. SynthLC is built on top of another automated approach/tool, called RTL2MμPATH, for synthesizing (“uncovering”) a complete set of formally verified microarchitectural execution paths (μPATHs) for each instruction from processor RTL. This deign choice exploits our key observation: μPATH variability (>1 μPATH) for an instruction strongly indicates there is a hardware side-channel in the input design.



Bio
Caroline Trippel is an Assistant Professor in the Computer Science and Electrical Engineering Departments at Stanford University working in the area of computer architecture. A central theme of her work is leveraging formal methods techniques to design and verify hardware systems in order to ensure that they can provide correctness and security guarantees for the applications they intend to support. Trippel’s research has been recognized with and NSF CAREER Award, IEEE Top Picks distinctions, the 2024 Intel Rising Star Award, the 2023 Intel Outstanding Researcher Award, the 2020 ACM SIGARCH/IEEE CS TCCA Outstanding Dissertation Award, and the 2020 CGS/ProQuest® Distinguished Dissertation Award in Mathematics, Physical Sciences, & Engineering. She was also awarded an NVIDIA Graduate Fellowship (2017-2018) and selected to attend the 2018 MIT Rising Stars in EECS Workshop.

If you want to join, contact socialmedia@iaik.tugraz.at until 13th of Nov, 15:00 for the invite link!

Bachelor@IAIK 2024/25

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At the event we present our new open bachelor’s thesis (and master’s thesis) topics and award prizes to excellent students.  

If you’re interested in joining us for your bachelor’s thesis in security, this is the best way to get an impression of our topics as well as how a bachelor’s thesis at IAIK works: You’ll hear about our research areas and current hot topics, our Bachelor@IAIK program where you can work on your thesis together with your fellow students in one of our offices if you like, and maybe you’ll get to know your supervisor while chatting along.

THE AWARDS:

IAIK Student Research Excellence Award: Students at IAIK who became co-authors of a scientific publication in the context of a thesis or project receive this award.

IAIK Bachelor Excellence Award: This award is for students majoring in “Information Security” at TU Graz and who have completed their bachelor’s degree with distinction at TU Graz. Application deadline: Oct 9th 2024!

The event will also be the kick-off lecture in Introduction to Scientific Working (ISW) where you will be able to choose your preferred topic!   

We are looking forward to meeting you!

 

Security in a World of Software Supply-Chain Vulnerabilities

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Abstract
Modern software incorporates thousands of third-party components. Bugs or security vulnerabilities in these components can seriously compromise the integrity of incorporating applications. Because of their widespread use, and the difficulty of vetting the enormous number of integrated components for vulnerabilities, they comprise a compelling target for attackers, who purposefully insert vulnerabilities into widely used components with the goal of compromising the integrity of entire software ecosystems.

I will present a series of systems that leverage component boundaries to offer automated solutions to vulnerabilities that appear in the software component supply chain. These solutions leverage system- and language-level containment techniques to prevent different classes of attacks from affecting these applications and the broader system in which they execute. Combined, they provide a holistic and in-depth transformation-based approach to securing software ecosystems.

Bio
Nikos Vasilakis is an Assistant Professor of Computer Science at Brown University. His research encompasses systems, programming languages, and security — and has been recognized by several distinguished paper awards. His current focus is on automatically transforming systems to add new capabilities such as parallelism, distribution, and security — against a variety of threat models. Nikos is also the chair of the Technical Steering Committee behind PaSh, a shell-script optimization system hosted by the Linux Foundation.

More: https://nikos.vasilak.is




Photo provided by speaker

Auction-Based Scheduling: A Modular Framework for Multi-Objective Decision-Making

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Abstract
Sequential decision-making tasks often require satisfaction of multiple, partially-contradictory objectives. Existing approaches are monolithic, where a single policy fulfills all objectives. I will present auction-based scheduling, a new modular framework for multi-objective sequential decision-making. In this framework, each objective is fulfilled using a separate and independent policy. The policies are then composed through a novel run-time composition mechanism, where at each step, they need to bid from pre-allocated budgets for the privilege of choosing the next action. The bidding encourages the policies to adjust their bids according to their urgencies to act, and whoever bids the highest gets scheduled first. We study the following decentralized synthesis problem: How to compute bidding-equipped policies whose composition will simultaneously fulfill all objectives? I will present solutions of the decentralized synthesis problem for path planning on finite graphs with two temporal objectives.

Bio
Kaushik Mallik is a postdoctoral researcher at the Institute of Science and Technology Austria (ISTA). His research interests are broadly in formal verification and synthesis of reactive software. He received the 2023 ETAPS Doctoral Dissertation Award, nominations for best paper awards in HSCC and TACAS, and a number of merit-based fellowships during his bachelor’s and master’s studies. He holds B. Tech (2012) in Electrical Engineering from Meghnad Saha Institute of Technology (India), M. Tech (2015) in System and Control from IIT Roorkee (India), and Dr. rer. nat. (PhD, 2022) in Computer Science from RPTU Kaiserslautern (Germany).




Photo provided by speaker

Guiding Function Synthesis with Machine Learning

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Abstract
Syntax-Guided Synthesis describes a format for function synthesis problems within a first-order theory. In addition to conventional semantic constraints stated in a first-order theory, SyGuS also allows for the posing of syntactic constraints through the use of a grammar. Most SyGuS solvers can be classified as enumerative solvers that systematically search the space through the space of functions that adhere to the syntactic constraint. However, these strategies suffer from the combinatorial explosion of the solution space.
In this talk I will present machine learning based methods to guide a search through this large search space. In the first part of this talk I will present how we utilize Monte-Carlo tree search with reinforcement learning. This method is inspired by AlphaZero. In the second part, I will present our most recent work on using LLMs to guide the search. We use LLMs to calculate probabilities for the production rules of the grammar and subsequently generate functions according to those probabilities. We evaluate and compare two different prompting methods to obtain the probabilities.

Bio
I recently finished my PhD at the University of Oxford under the supervision of Daniel Kroening and Tom Melham with a thesis titled “Machine Learning for Function Synthesis”. Generally, I am interested in automated reasoning or computer-aided verification of mathematical proofs, software, and hardware (in no particular order). Apart from my PhD I worked at the University of Edinburgh and the University of Innsbruck as a research associate where I also worked on computational logic, theorem proving, and term rewriting. I lived in Innsbruck, Austria most of my life and also obtained my Undergrad and Masters at the University of Innsbruck.




Photo provided by speaker

About time for cache attacks

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Abstract
Over the last two decades, cache attacks have emerged as a significant threat to shared computing. At their core, cache attacks exploit minute timing variation to query the state of a cache in the computer. From this cache state, the attacker can infer secret data processed by victim software that uses the shared cache. As these attacks often measure minute variations, at the order of few nanoseconds, multiple proposed defences aim at depriving attackers of high-resolution clocks.
In this talk we show the futility of such attempts. We first show that coarse-grained cache attack can retrieve sensitive information even in the absence of high-resolution timers. We then delve deeper into the nature of cache attacks, demonstrating that they allow arbitrary computation on cache state. Finally, we show how attackers can exploit this observation to implement high-frequency, high-resolution cache attacks without using high-resolution timers.

Bio
Yuval Yarom is a professor at Ruhr University Bochum, where he leads the Chair for Computer Security. He earned his Ph.D. in Computer Science from the University of Adelaide in 2014, and an M.Sc. in Computer Science and a B.Sc. in Mathematics and Computer Science from the Hebrew University of Jerusalem in 1993 and 1990, respectively. In between he has been the Vice President of Research in Memco Software and a co-founder and Chief Technology Officer of Girafa.com.
Yuval’s research explores the security of the interface between the software and the hardware. In particular, he is interested in the discrepancy between the way that programmers think about software execution and the concrete execution in modern processors. He works on identifying micro-architectural vulnerabilities, and on exploitation and mitigation techniques.




Photo © Hilary Brooks

New Techniques for Efficient Isogeny-based Encryption Protocols

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Abstract

Isogeny-based cryptography is known for its low bandwidth requirements, which often come at the cost of slower computations. SIDH, one of the most well-known isogeny-based key exchanges, and the only one submitted to the NIST standardisation process, was broken in 2022 in a series of three breakthrough papers. The attack relies on isogenies between abelian varieties (a generalisation of elliptic curves to higher dimensions), and it leads to a complete key recovery within seconds.

In this talk, we discuss two approaches to obtaining secure protocols that could, eventually, replace SIDH. The first approach involves modifying the SIDH protocol to include simple but effective countermeasures against all known attacks. The technique is based on restricting the set of potential isogenies, so that less information about the secret isogeny (in the form of torsion images) need to be revealed.

The second approach is based on the development of a new PKE, which we call FESTA. The attacks on SIDH rely on higher-dimensional isogenies to make some computations, previously believed to be hard, extremely efficient. In FESTA, we use the same techniques constructively: we build a trapdoor function where the inversion operation consists of recovering an SIDH secret key. From the trapdoor, it is then simple to obtain an IND-CCA PKE through standard transformations.

Bio
Andrea Basso is a postdoctoral researcher at the University of Bristol, where he focuses on developing new isogeny-based protocols, with a particular interest in advanced functionalities such as non-interactive key exchanges and oblivious pseudorandom functions. He received his PhD from the University of Birmingham, and he will soon join IBM Research Zurich as a postdoctoral researcher.



Photo © Private

Imitation Learning and Value Alignment Under Mismatch and Constraints

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Short bio:
Dr. Sebastian Tschiatschek is assistant professor at the University of Vienna.

He is part of the research group for Data Mining and Machine Learning, leading the work group for Probabilistic and Interactive Machine Learning.

He is also an alumni of TU Graz.

Abstract:

Reinforcement learning has been successfully used for training AI agents when given clearly defined reward signals. However, reinforcement learning can suffer from high sample complexity and is challenging to use in settings in which the reward signal is hard to specify, e.g., for training personal agents that should maximize a human-defined reward function. We investigate imitation learning and reinforcement learning from human feedback which allows us to avoid the specification of a reward function and can drastically reduce sample complexity. Inspired by real-world applications, we particularly study settings in which there is a mismatch between the human providing demonstrations or feedback and the learning AI agent, e.g., in terms of observations, capabilities, or constraints. Our insights emphasize the need for adaptation of the human and the AI agent to achieve the best alignment regarding the human’s goals. Furthermore, we propose practical algorithms to perform this adaptation and sample efficient approaches for learning about rewards and constraints.

Photo: ©University of Vienna

Propagation of Subspaces in Primitives with Monomial Sboxes

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Abstract

Motivated by progress in the field of zero-knowledge proofs, so-called Arithmetization-Oriented (AO) symmetric primitives have started to appear in the literature, such as MiMC, Poseidon or Rescue. Due to the design constraints implied by this setting, these algorithms are defined using simple operations over large (possibly prime) fields. In particular, many rely on simple low-degree monomials for their non-linear layers.
In this work, we show that the structure of the material injected in each round (be it subkeys in a block cipher or round constants in a public permutation) could allow a specific pattern, whereby a well-defined affine space is mapped to another by the round function, and then to another, etc. Such chains of one-dimensional subspaces always exist over 2 rounds, and they can be extended to an arbitrary number of rounds provided that the round-constants are well chosen.
As a consequence, for several ciphers like Rescue, or a variant of AES with a monomial Sbox, there exist some round-key sequences for which the cipher has an abnormally high differential uniformity, exceeding the size of the Sbox alphabet.
Well-known security arguments, in particular based on the wide trail strategy, have been reused in the AO setting by many designers.
Unfortunately, our results show their limits. To illustrate this, we present two new primitives (a tweakable block cipher and a permutation-based hash function) that are built using state-of-the-art security arguments, but which are actually deeply flawed.

Bio
Anne Canteaut is a Researcher in the COSMIQ project-team at INRIA, and an Honorary Doctor at the University of Bergen (Norway).

Her main research interest is symmetric cryptography.
(Source & further details on: https://www.rocq.inria.fr/secret/Anne.Canteaut/English/index.html)

Photo copyright: © Inria / Photo C. Morel