Cryptography | UCS

Paper accepted at ICICS 2026

Sat, 01 Aug 2026 00:00:00 +0000

We are delighted to announce that the paper “Toward Secure Compilation: Leakage Detection for Masked Implementations in Jasmin” has been accepted at ICICS 2026, the 28th International Conference on Information and Communications Security.

What is it about? Cryptography quietly protects everyday things such as bank cards, car keys and instant messages. Surprisingly, attackers do not always need to break the mathematics behind it: while a chip encrypts, its power consumption fluctuates ever so slightly, and from these tiny fluctuations the secret key can sometimes be reconstructed, much like guessing what someone is typing just from the sound of the keystrokes. Programmers have techniques to guard against this, but the tools that translate a program into instructions for the chip can unintentionally weaken that protection. Our paper teaches one of these tools to detect such hidden weaknesses on its own and to point developers to their exact origin.

The paper was written by UCS researchers Nicolai Schmitt, Sven Wroblewski and Andreas Heinemann together with Fabio Campos (Hochschule Darmstadt).

Masking is a well-established software countermeasure against side-channel attacks. In practice, however, even an algorithmically correct masked implementation can still leak on real hardware, because the compiler and the microarchitecture of the target device may recombine values that the masking scheme was designed to keep separate. Established tools address this either through leakage simulation, which depends on a specific power model and is computationally expensive, or through formal verification of the source program, which does not cover the effects introduced by the later compilation stages.

The publication approaches this gap from within the compiler itself and presents a leakage detection pass for the Jasmin language, integrated into its formally verified compilation pipeline. Instead of simulating power traces, the analysis makes the causes of the detected leakage explicit, which allows developers to trace a finding back to its origin in the source program. The authors validate the approach on a structured set of test cases and intend it as the foundation for a subsequent compiler stage that removes the detected leakage automatically, thus constituting a first step toward secure compilation.

The paper will be presented at ICICS 2026 in Fukui, Japan, from 27 to 30 October 2026, and will appear in the conference proceedings published by Springer in the LNCS series. The acceptance highlights the ongoing research activities of the UCS group in the fields of secure compilation, side-channel analysis and the secure implementation of cryptographic primitives.

Preprint: Cryptology ePrint Archive, Paper 2026/1696

Paper accepted at AfricaCrypt 2026

Tue, 12 May 2026 00:00:00 +0000

The paper “The Best of Both Worlds: Hybrid Authenticated Key Exchange for QKD(N) without Signatures” was authored by Sebastian Clermont (TU Darmstadt) and UCS researcher Johanna Henrich.

The publication proposes a hybrid authenticated key exchange that completely removes the need for digital signature schemes in order to reduce the cryptographic attack surface and improve crypto-agility. Instead, the protocol combines Post-Quantum Cryptography (PQC) and QKD-based key agreement while leveraging PQC Key Encapsulation Mechanisms (KEMs) for both authentication and key exchange.

In addition, the paper provides a fully modular security analysis and the practical feasibility is demonstrated through benchmark implementations using ML-KEM, FrodoKEM, and Classic McEliece.

The work was carried out in collaboration with TU Darmstadt as part of the ATHENE research project SATURN.

The acceptance at AfricaCrypt 2026 highlights the ongoing research activities of the UCS group in the fields of quantum-secure communication, applied Cryptography and crypto-agility.

PQC Update 2026

Tue, 12 May 2026 00:00:00 +0000

Johanna Henrich participated in the PQC Update 2026 organized by Fraunhofer AISEC. The event brought together experts from academia, industry, and public institutions to discuss the current state of PQC, migration challenges, and practical deployment strategies.

The meeting covered recent developments in standardization activities, migration planning for cryptographic infrastructures, and experiences from ongoing PQC transition projects. In addition, the event provided valuable opportunities for networking and exchange with researchers and practitioners working on quantum-safe security technologies.

Participation in the event supports the ongoing activities within the SATURN project, particularly regarding secure communication infrastructures and the transition towards quantum-resistant cryptographic mechanisms.