“Receiving both Eurocrypt Test of Time Awards in the same year is extremely rare and highlights the breadth of cryptography research at Aarhus University, from advanced secure computation protocols to high-performance cryptographic engineering,” says Professor Claudio Orlandi, head of the Cryptography and Cybersecurity section. “It is also special to see that both awarded papers originated from PhD work and continue to influence research and real-world cryptographic systems 15 years later.”

While the award-winning paper by Claudio and Ivan was authored entirely by Aarhus University researchers, Diego’s award-winning paper was the result of an international collaboration spanning Brazil and Canada. 

Semi-Homomorphic Encryption and Multiparty Computation 

Professor Claudio Orlandi and Professor Ivan Damgård receive the award for the paper Semi-Homomorphic Encryption and Multiparty Computation, co-authored with Rikke Bendlin and Sarah Zakarias.  

The paper introduced new techniques for secure multiparty computation (MPC) - a field focused on enabling parties to compute on sensitive data without revealing the data itself. The work showed how semi-homomorphic encryption and information-theoretic message authentication codes (MACs) could be combined to create highly efficient MPC protocols secure even against dishonest participants.  

The award citation states: “For pioneering the use of homomorphic information-theoretic MACs in MPC and inspiring numerous breakthroughs in both information-theoretic and computational MPC.” 

Faster Explicit Formulas for Computing Pairings over Ordinary Curves 

The other Test of Time award goes to Associate Professor Diego F. Aranha for the paper Faster Explicit Formulas for Computing Pairings over Ordinary Curves, co-authored with Koray Karabina, Patrick Longa, Catherine H. Gebotys and Julio López.

The paper significantly improved the efficiency of cryptographic pairings - mathematical tools that underpin many modern cryptographic systems, including identity-based encryption and advanced digital signatures. The researchers introduced new algorithmic techniques and optimization methods that reduced computation times significantly and influenced subsequent research and implementations in pairing-based cryptography.

The award citation states: “For defining the key aspects of efficient pairing implementations on ordinary curves and introducing algorithmic techniques that have been widely adopted in subsequent research.” 

The IACR Test of Time Award is presented annually by the International Association for Cryptologic Research (IACR) to papers from the organization’s flagship conferences that have demonstrated lasting scientific impact 15 years after publication. See previous recipients here: https://www.iacr.org/testoftime/