Events

QNC building, 200 University Ave. Room 0101, Waterloo 

This workshop focuses on encoding quantum information in more than two states.

The main theme is to go beyond binary encodings: from quBits to quDits, where D > 2.

Now is a very interesting time, as we see a lot of experimental progress and new possibilities in this area. This workshop brings together researchers  – both experimentalists and theorists – to explore quDit-based applications in all areas of quantum technology.

IQC CS/Math Seminar, Xiangling Xu INRIA Saclary

QNC building, 200 University Ave. Room 1201, Waterloo 

Characterizing quantum correlations is a fundamental task in the study of quantum information theory. In the standard Bell scenario, where the correlations are established by a single source, the seminal work [Navascúes et al., 2008] presents a convergent hierarchy that provides an outer approximation, which can be formulated as a problem solvable by computers.

In the more general networks scenarios, however, the correlations are due to multiple independent quantum sources. This necessitates a generalization of the NPA hierarchy. Based on [Renou, Xu, Ligthard, 2022], this talk focuses on the simplest quantum network, the bilocal scenario, where two independent quantum sources exist: one shared between Alice and Bob, and the other between Bob and Charlie. It will discuss two convergent generalizations of the NPA hierarchy in this context, demonstrating that the bilocal scenario is completely understood from the algebraic/Heisenberg perspective.

Despite this progress, the characterization of quantum networks beyond the bilocal scenario remains an open question. This talk will introduce a possible approach, the inflation-NPA hierarchy, as a potential solution. The aim is to motivate the audience to explore this important and challenging problem further.

IQC Special Seminar, Jerome Wiesemann, Fraunhofer Heinrich Hertz Institute HHI

Quantum key distribution (QKD) is on the verge of becoming a robust security solution, backed by security proofs that closely model practical implementations.  As QKD matures, a crucial requirement for its widespread adoption is establishing standards for evaluating and certifying practical implementations, particularly against side-channel attacks resulting from device imperfections that can undermine security claims. Today, QKD is at a stage where the development of such standards is increasingly prioritized. This works aims to address some of the challenges associated with this task by focusing on the process of preparing an in-house QKD system for evaluation. We first present a consolidated and accessible baseline security proof for the one-decoy state BB84 protocol with finite-keys, expressed in a unified language. Building upon this security proof, we identify and tackle some of the most critical side-channel attacks by characterizing and implementing countermeasures both in the QKD system and within the security proof. In this process, we iteratively evaluate the risk of the individual attacks and re-assess the security of the system. Evaluating the security of QKD systems additionally involves performing attacks to potentially identify new loopholes. Thus, we also aim to perform the first real-time Trojan horse attack on a decoy state BB84 system, further highlighting the need for robust countermeasures. By providing a critical evaluation of our QKD system and incorporating robust countermeasures against side-channel attacks, our research contributes to advancing the practical implementation and evaluation of QKD as a trusted security solution.

Improving information transmission using correlated auxiliary noise

QNC building, 200 University Ave. Room 1201, Waterloo 

Communicating information is a fundamentally important task that is often limited by noise. The physical origin of noise in a quantum channel is an interaction between the transmitted system and its surrounding environment. This interaction leads to correlations between the system and its environment that contain information about the original state, but are inaccessible to the receiver. However, a receiver may be able to recover some of this lost information if they are given access to an additional auxiliary system that interacts with the environment. In this talk, I will formalize a particular type of receiver side information and characterize the resulting improvement in classical and quantum channel capacities for an augmented bit flip channel. I will then discuss information-theoretic bounds on imperfect one-time pad cryptography schemes and passive environment-assisted quantum channel capacities.

Douglas Stebila, University of Waterloo

QNC building, 200 University Ave. Room 1201, Waterloo 

This workshop will provide an introduction to the Tamarin prover, which is a security protocol verification tool that analyzes cryptographic protocols in a symbolic model and can automatically identify attacks or conclude that certain classes of attacks do not exist. The workshop will include a hands-on exercise using the Tamarin prover.

To attend this program please email us at cryptoworks21@uwaterloo.ca by July 16, 2024.

Daniel Nino, Xanadu

QNC building, 200 University Ave. Room 1201, Waterloo 

Xanadu is a Canadian quantum computing company with the mission to build quantum computers that are useful and available to people everywhere. Xanadu is one of the world’s leading quantum hardware and software companies and also leads the development of PennyLane, an open-source software library for quantum computing and application development.

Through this workshop, attendees will be given a broad overview of some applications of quantum computing to quantum chemistry. Through a series of hands-on exercises, attendees will learn about some PennyLane functionalities for workflows in quantum chemistry. By the end of the session, they will have hands-on experience in building quantum programs with PennyLane and how to use PennyLane datasets in applications to reduce time to research.

Please bring a laptop with you for this session. The workshop will run over Google Colab, no specific installation is required.

Elena Bakos Lang and Kevin Henry, NCC Group

QNC building, 200 University Ave. Room 1201, Waterloo 

The security of cryptographic primitives and protocols is inextricably tied to that of the implementations deployed in the real world. Ensuring that these implementations are as secure as possible is thus a problem at the heart of cryptographic security.

This workshop will introduce common classes of cryptographic vulnerabilities, including improper randomness generation, side-channel attacks, flaws in primitives or protocols, and others, and discuss secure coding practices that can help mitigate them, based on our experiences auditing cryptographic code. This discussion will be complemented by a set of practical exercises to provide experience in spotting insecure constructions. Additionally, as implementation quality is often tied to the quality of the source material, we will present a case study on a recent widely implemented threshold signing protocol where ambiguous or unclear presentation in the academic source material has led to multiple critical implementation vulnerabilities.

This workshop is presented by NCC Group Cryptography Services practice in Waterloo, Ontario.

To attend this program please email us at cryptoworks21@uwaterloo.ca by July 17, 2024.

The QKD security proof workshop is an annual workshop series focused on technical security proofs. Our focus in the workshop is to facilitate interactions and discussions between participants.