Symmetric Key Agreement Workshop (SKAW) 2024

Santa Barbara, August 18, 2024

An affialiated workshop of Crypto 2024

Workshop Description

In the past few decades, asymmetric cryptography has been the rising star of key agreement protocols. In this workshop, we aim to shine light on the secure alternative of Symmetric Key Agreement (SKA).

There is growing evidence for real-world use cases of SKA by various IETF standards, NIST guidelines, and NSA requirements, including the use of Symmetric Pre-Shared Keys for enhanced quantum-resistant protection. The goal of the SKA Workshop is to examine how symmetric keys can reduce reliance on asymmetric cryptography by providing alternative and/or additional layers of security. We aim to gather academic and industrial experts to discuss the solutions that SKA can offer.

SKAW is designed to promote research and application use case of symmetric-key cryptography and protocols. There is a particular focus on applications to industry.

Broadly, the scope of the workshop includes, but is not limited to:

Keynote Speakers

Ian Blumenfield
Ian Blumenfield
Two Six Technologies
Formal Analysis for SKA Protocols
Adrian Stanger
Adrian Stanger
National Security Agency (NSA)
Talk Title TBD


9:00am Workshop welcome
9:15am Keynote: Adrian Stanger
10:15am Coffee break
10:45am Session talks - part one
12:15pm Lunch
2pm Session talks - part two
2:30pm Keynote: Ian Blumenfeld
3:30pm Coffee break
4:00pm Panel/discussion
5pm Finish

Talk Descriptions

Session talks - part one

  1. Conor Spangler, Arqit. 13 ways to establish keys using symmetric methods, and why you might want more
    We examine the methods of the ISO/IEC 11770-2 which cover point-to-point, key distribution and key translation. We will consider the security properties of the methods as laid out in the standard and a more comprehensive list from academic proposals. We will also consider more abstract security goals such as zero trust, defence in depth, and cryptographic agility and usability metrics such as round trip count and number of calls to primitives. We will see how existing symmetric key methods can be described under the framework and how other proposals could be similarly evaluated.
  2. Manfred von Willich , QuantumBridge. Distributed Symmetric Key Establishment: cryptographic primitives”
    Distributed Symmetric Key Establishment is a protocol that provides a practical, scalable, robust solution to the challenge posed by the quantum threat, and has a rigorous proof of information-theoretic security in a distributed trust model. This presentation gives a detailed insight into the composition of its primitives, all well-known. One such composition with a novel property provides end-to-end authentication without a prior shared secret while eliminating share manipulation attacks by rogue semi-trusted entities.
  3. David Jao, EvolutionQ. Quantum-secure end-to-end key establishment using Multimodal Cryptography
    We present a crypto-agile protocol for quantum-secure end-to-end (E2E) encryption key establishment with extremely strong security properties. It is based on a concept that we call multimodal cryptography, which combines various forms of computational cryptography (symmetric-key, asymmetric-key, and post-quantum). If available, quantum key distribution (QKD) can be seamlessly integrated to further fortify the key establishment process. Alternatively, if the availability of QKD is taken as a given, one can consider multimodal cryptography a solution to quantum communication’s last-mile problem.

Session talks - part two

  1. Christopher Batterbee, University of Sorbonne. Muckle++: Improved Quantum-Secure Hybrid Key Exchange”
    End-to-end authenticity in public networks plays a significant role. Namely, without authenticity, the adversary might be able to retrieve even confidential information straight away by impersonating others. Proposed solutions to establish an authenticated channel cover pre-shared keybased, password-based, and certificate-based techniques. To add confidentiality to an authenticated channel, authenticated key exchange (AKE) protocols usually have one of the three solutions built in. As an amplification, hybrid AKE (HAKE) approaches are getting more popular nowadays and were presented in several flavors to incorporate classical, post-quantum, or quantum-key-distribution components. The main benefit is redundancy, i.e., if some of the components fail, the primitive still yields a confidential and authenticated channel.
    At PQCrypto20, Dowling, Brandt, Hansen, and Paterson introduced a new modular framework for designing HAKE and presented a first instantiation, dubbed Muckle, requires pre-shared keys (and hence yields inefficient end-to-end authenticity). Recently (at PQCrypto23), Bruckner, Ramacher and Striecks proposed a new extended instantiation called Muckle+, that utilizes post-quantum digital signatures. In this talk, we will present Muckle++ that extends previous works by using post-quantum KEM for authentication. While replacing pre-shared keys with public-key authenticators is rather straightforward, the challenge is to derive the proof in the HAKE framework. As emphasised in KEMTLS, the main motivation is that pq KEM turn to be more efficient than pq signature schemes.
    Joint work with Sebastian Ramacher, Christoph Striecks, Ludovic Perret.


The workshop is an affiliated event of Crypto 2024. To register to the workshop, please register to CRYPTO 2024, and mark in the registration form the SKAW event.

There is limited funding available to provide free admission to SKAW for university students. Please email if you are eligible.

Steering Committee

Program Committee