Research
My research is focused on the foundational security and practical implementation of cryptographic protocols within blockchain technologies. I design and formally analyse composable protocols for decentralized systems, from scaling solutions such as ZK and optimistic rollups, through cross-chain interoperability, to mechanisms for on-chain governance and voting.
A central thread of my work is the automated verification of protocols and security proofs using formal-methods tools such as model checking.
My interests also cover core cryptographic primitives (e.g., memory-hard functions, authenticated encryption, and block ciphers) and cutting-edge functionalities like homomorphic and functional encryption.
See also my DBLP and Google Scholar pages.
In submission
- UC, Categorically: Rigorous Diagrammatic Proofs In submission, 2026
Publications
- Crossing with Confidence: Formal Analysis and Model Checking of Blockchain Bridges Theory and Application of Cryptology and Information Security, ASIACRYPT 2026
- Multi-Instance Unrecoverability of iMHF-Based Password Hashing European Symposium on Research in Computer Security, ESORICS 2026
- Beyond Blockchain Ballots: UC-Secure Layer-2 Voting and Governance IEEE Computer Security Foundations Symposium, CSF 2026
- Multi-Source Randomness Extraction and Generation in the Random-Oracle Model Information-Theoretic Cryptography, ITC 2025
- Block Ciphers in Idealized Models: Automated Proofs and New Security Results ACM Conference on Computer and Communications Security, CCS 2024
- The Brave New World of Global Generic Groups and UC-Secure Zero-Overhead SNARKs Theory of Cryptography Conference, TCC 2024
- The Uber-Knowledge Assumption: A Bridge to the AGM IACR Communications in Cryptology, CiC 2024
- Beyond Uber: Instantiating Generic Groups via PGGs Theory of Cryptography Conference, TCC 2022
- Password Hashing and Preprocessing Theory and Applications of Cryptographic Techniques, EUROCRYPT 2021
- Black-Box Uselessness: Composing Separations in Cryptography Innovations in Theoretical Computer Science, ITCS 2021
- The Key-Dependent Message Security of Key-Alternating Feistel Ciphers Cryptographers' Track at the RSA Conference, CT-RSA 2021
- Towards Defeating Backdoored Random Oracles: Indifferentiability with Bounded Adaptivity Theory of Cryptography Conference, TCC 2020
- Multilinear Maps from Obfuscation Journal of Cryptology 2020 Theory of Cryptography Conference, TCC 2016-A
- Simpler Constructions of Asymmetric Primitives from Obfuscation Cryptology in India, INDOCRYPT 2020
- Security of Symmetric Primitives against Key-Correlated Attacks IACR Transactions on Symmetric Cryptology, ToSC (FSE) 2019
- Indifferentiable Authenticated Encryption International Cryptology Conference, CRYPTO 2018
- Combiners for Backdoored Random Oracles International Cryptology Conference, CRYPTO 2018
- Graded Encoding Schemes from Obfuscation Practice and Theory of Public-Key Cryptography, PKC 2018
- Security of Even–Mansour Ciphers under Key-Dependent Messages IACR Transactions on Symmetric Cryptology, ToSC (FSE) 2018
- Security of Symmetric Primitives under Incorrect Usage of Keys IACR Transactions on Symmetric Cryptology, ToSC (FSE) 2017
- Modeling Random Oracles under Unpredictable Queries Fast Software Encryption, FSE 2016
- Private Functional Encryption: Indistinguishability-Based Definitions and Constructions from Obfuscation Cryptology in India, INDOCRYPT 2016
- Polly Cracker, Revisited Designs, Codes and Cryptography 2016 Theory and Application of Cryptology and Information Security, ASIACRYPT 2011
- A More Cautious Approach to Security Against Mass Surveillance Fast Software Encryption, FSE 2015
- The Related-Key Security of Iterated Even–Mansour Ciphers Fast Software Encryption, FSE 2015
- Random-Oracle Uninstantiability from Indistinguishability Obfuscation Theory of Cryptography Conference, TCC 2015
- Indistinguishability Obfuscation and UCEs: The Case of Computationally Unpredictable Sources International Cryptology Conference, CRYPTO 2014
- The Related-Key Analysis of Feistel Constructions Fast Software Encryption, FSE 2014
- Ideal-Cipher (Ir)reducibility for Blockcipher-Based Hash Functions Theory and Applications of Cryptographic Techniques, EUROCRYPT 2013
- Robust Encryption, Revisited Practice and Theory of Public-Key Cryptography, PKC 2013
- On the Semantic Security of Functional Encryption Schemes Practice and Theory of Public-Key Cryptography, PKC 2013
- On the Relationship between Functional Encryption, Obfuscation, and Fully Homomorphic Encryption IMA Conference on Cryptography and Coding, IMACC 2013
- Delegatable Homomorphic Encryption with Applications to Secure Outsourcing of Computation Cryptographers' Track at the RSA Conference, CT-RSA 2012
- On the Joint Security of Signature and Encryption under Randomness Reuse: Efficiency and Security Amplification Applied Cryptography and Network Security, ACNS 2012
- On Cipher-Dependent Related-Key Attacks in the Ideal-Cipher Model Fast Software Encryption, FSE 2011
- Relations among Notions of Complete Non-Malleability: Indistinguishability Characterisation and Efficient Construction without Random Oracles Australasian Conference on Information Security and Privacy, ACISP 2010
- Strong Knowledge Extractors for Public-Key Encryption Schemes Australasian Conference on Information Security and Privacy, ACISP 2010
- Security Analysis of Standard Authentication and Key Agreement Protocols Utilising Timestamps Cryptology in Africa, AFRICACRYPT 2009
- Certified Encryption Revisited Cryptology in Africa, AFRICACRYPT 2009
- Certificateless Signcryption ACM Symposium on Information, Computer and Communications Security, ASIACCS 2008
- Generic Constructions of Identity-Based and Certificateless KEMs Journal of Cryptology 2008
- Randomness Reuse: Improvements and Extensions IMA Conference on Cryptography and Coding, IMACC 2007
- Secure Cryptographic Workflow in the Standard Model Cryptology in India, INDOCRYPT 2006
- Efficient Identity-Based Key Encapsulation to Multiple Parties IMA Conference on Cryptography and Coding, IMACC 2005
Other
- Innovative Security Solutions for Information Technology and Communications — 10th International Conference, SecITC 2017 LNCS 10543, Springer, 2017
- Extensions of Public-Key, Identity-Based and Certificateless Encryption Schemes PhD thesis, University of Bristol, 2008
- SK-KEM: An Identity-Based KEM Submission to IEEE P1363.3, 2006
Co-authors
Martin R. Albrecht (3), Joël Alwen, Miguel Ambrona, Afonso Arriaga (2), Paul Baecher, Manuel Barbosa (15), Balthazar Bauer (3), Kamel Bentahar, Raghav Bhaskar, Jan Bobolz, Christina Brzuska (2), Pyrros Chaidos, Liqun Chen, Zhaohui Cheng, Mark Chimley, Aisling Connolly, Sandro Coretti, Geoffroy Couteau, Jean Paul Degabriele, Alexander W. Dent, Charles Dodd, Yevgeniy Dodis, Jean-Charles Faugère, Denis Firsov, Marc Fischlin, Matthias Fitzi, Georg Fuchsbauer (2), Rosario Gennaro, S. Dov Gordon, Shuai Han, Patrick Harasser (4), Keith Harrison, Gottfried Herold, Julia Hesse, Dennis Hofheinz (2), Dimitar Jetchev, Martti Karvonen, Louiza Khati (2), Aggelos Kiayias (2), Andre Knispel, Markulf Kohlweiss (4), Enrique Larraia (2), Benoît Libert, Mohammad Mahmoody, John Malone-Lee (2), Sogol Mazaheri (2), Arno Mittelbach (3), Anca Nitulescu, Adam O'Neill, Claudio Orlandi, Alain Passelègue, Kenneth G. Paterson (3), Ludovic Perret, Bertram Poettering, Gordon Procter, Elizabeth A. Quaglia, Răzvan Roşie, Yannick Seurin, Siamak F. Shahandashti, Nigel P. Smart (2), Karl Southern (2), Martijn Stam, Akira Takahashi, Stefano Tessaro (3), Frederik Vercauteren, Damien Vergnaud (2), Philip Wadler, Bogdan Warinschi, Gaven J. Watson, and David A. Wilson.