Adrián Pérez Keilty
PhD researcher | Cryptography
Chalmers University of Technology
About Me
Welcome! I'm a PhD researcher in Cryptography at Chalmers University of Technology, under the supervision of Elena Pagnin and Andrei Sabelfeld. My research focuses on progressive and efficient verification of cryptographic protocols, building upon this prior work. I am also interested in quantum computing and cryptanalysis of hash functions. I hold a BS in Pure Mathematics from Complutense University of Madrid and a MS in Advanced Mathematics and Cryptography from Linnaeus University.
Research
Efficient Verifiable Computation
This project aims to develop a new protocol for efficiently and securely outsourcing bilinear pairings computations from a resource-constrained device to a more powerful but untrusted server. Our resulted protocol yields savings of up to 83% achieved by the client compared to locally computing pairings.
Algebraic cryptanalysis of hash functions
By using symbolic processing, boolean minimization techniques and SAT solvers, we aim to express hash functions as systems of equations in $GF(2)$ and find collisions and preimages more efficiently than existing generic attacks.
Publications
Delegating Bilinear Pairings: Systematization, Amortized Efficiency, and Future Directions
Licentiate thesis, 2026
Bilinear pairings are a fundamental tool in cryptography but computationally expensive when being run on resource-constrained devices, making delegation or outsourcing to a server a desirable alternative. However, designing a protocol that simultaneously verifies the server's output correctness and achieves efficiency over local computation has been a longstanding open problem. This thesis provides a systematization of existing work in this line of research, introduces the novel concepts of amortized efficiency and sequential delegation, and proposes new protocols that achieve significant and concrete efficiency gains for the first time in the literature.
That's AmorE: Amortized Efficiency for Pairing Delegation
CRYPTO, 2025
We introduce AmorE, a protocol for verifiable pairing delegation that achieves state-of-the-art efficiency. Unlike traditional protocols designed for unconditional security, AmorE achieves everlasting security through computational bounds during protocol execution, enabling significant efficiency gains: Delegating batches of 10 pairings on BLS48-575 costs the client less than a single $\mathbb{G}_2$ scalar multiplication per pairing on average, while maintaining at least 40 bits of statistical security.
A Hashing Algorithm Based on a One-Way Function in the Symmetric Group $S_n$
Master Thesis — Digitala Vetenskapliga Arkivet (DiVA), 2022
The large majority of hash functions are based on bitwise operations, and modular additions. This work explores an alternative approach by leveraging a conjectured one-way function in the symmetric group $S_n$, rendering all existing generic attacks useless, and therefore opening a new framework for cryptanalysis in this setting. The proposed hashing algorithm is implemented in C++ and evaluated through statistical tests to assess its performance and security properties.
Events
Teaching
Cryptography
Exercises and lab sessions covering fundamental concepts in modern cryptography, including Symmetric and Public Key Encryption, Hash functions, Digital Signatures, Blockchain Technology and $\Sigma$-protocols.
Language-Based Security
Lab supervision and grading. Topics: Race conditions (TOCTOU), Buffer Overruns, Web Application Security, Android App Security, JavaScript Sandboxing.
Computer Security
Lab supervision and grading. Topics: Public Key Cryptography, Operating System Security, Denial of Service Attacks, Intrusion Detection, Certificates.
Contact
CSE, Chalmers University of Technology
SE-412 96 Göteborg, Sweden