Research Interests
I am interested in the rigorous development of cryptographic primitives and protocols, as well as the relationships between primitives and protocols. My work at IOG centers around the design and analysis of composable layer-2 blockchain protocols. My work at Durham is on idealized models of computation (such as the random-oracle and generic-group models) and has been supported by an EPSRC new-investigator grant. In the past I have worked on cryptosystems with advanced functionalities (e.g., functional encryption, multi-linear maps, and obfuscation) and public-key and identity-based cryptosystems. A list of my publications appears below; see also my DBLP and Google Scholar pages.
Publications
Block Ciphers in Idealized Models: Automated Proofs and New Security Results.
CCS 2024.
The Brave New World of Global Generic Groups and UC-Secure Zero-Overhead SNARKs.
TCC 2024.
The Uber-Knowledge Assumption: A Bridge to the AGM.
CiC 2024.
Beyond Uber: Instantiating Generic Groups via PGGs.
TCC 2022.
Password Hashing and Preprocessing.
EUROCRYPT 2021.
Black-Box Uselessness: Composing Separations in Cryptography.
ITCS 2021.
The Key-Dependent Message Security of Key-Alternating Feistel Ciphers.
CT-RSA 2021.
Towards Defeating Backdoored Random Oracles: Indifferentiability with Bounded Adaptivity.
TCC 2020.
Multilinear Maps from Obfuscation.
Journal of Cryptology 2020.
TCC 2016-A.
Simpler Constructions of Asymmetric Primitives from Obfuscation.
INDOCRYPT 2020.
Security of Symmetric Primitives against Key-Correlated Attacks.
ToSC (FSE) 2019.
Indifferentiable Authenticated Encryption.
CRYPTO 2018.
Combiners for Backdoored Random Oracles.
CRYPTO 2018.
Graded Encoding Schemes from Obfuscation.
PKC 2018.
Security of Even–Mansour Ciphers under Key-Dependent Messages.
ToSC (FSE) 2018.
Security of Symmetric Primitives under Incorrect Usage of Keys.
ToSC (FSE) 2017.
Modeling Random Oracles under Unpredictable Queries.
FSE 2016.
Private Functional Encryption: Indistinguishability-Based Definitions and Constructions from Obfuscation.
INDOCRYPT 2016.
Polly Cracker, Revisited.
Designs, Codes and Cryptography 2016.
ASIACRYPT 2011.
A More Cautious Approach to Security Against Mass Surveillance.
FSE 2015.
The Related-Key Security of Iterated Even-Mansour Ciphers.
FSE 2015.
Random-Oracle Uninstantiability from Indistinguishability Obfuscation.
TCC 2015.
Indistinguishability Obfuscation and UCEs: The Case of Computationally Unpredictable Sources.
CRYPTO 2014.
The Related-Key Analysis of Feistel Constructions.
FSE 2014.
Ideal-Cipher (Ir)reducibility for Blockcipher-Based Hash Functions.
EUROCRYPT 2013.
Robust Encryption, Revisited.
PKC 2013.
On the Semantic Security of Functional Encryption Schemes.
PKC 2013.
On the Relationship between Functional Encryption, Obfuscation, and Fully Homomorphic Encryption.
IMA International Conference 2013.
Delegatable Homomorphic Encryption with Applications to Secure Outsourcing of Computation.
CT-RSA 2012.
On the Joint Security of Signature and Encryption under Randomness Reuse: Efficiency and Security Amplification.
ACNS 2012.
On Cipher-Dependent Related-Key Attacks in the Ideal-Cipher Model.
FSE 2011.
Relations among Notions of Complete Non-Malleability: Indistinguishability Characterisation and Efficient Construction without Random Oracles.
ACISP 2010.
Strong Knowledge Extractors for Public-Key Encryption Schemes.
ACISP 2010.
Security Analysis of Standard Authentication and Key Agreement Protocols Utilising Timestamps.
AFRICACRYPT 2009.
Certified Encryption Revisited.
AFRICACRYPT 2009.
Certificateless Signcryption.
ASIACCS 2008.
Generic Constructions of Identity-Based and Certificateless KEMs.
Journal of Cryptology 2008.
Randomness Reuse: Improvements and Extensions.
IMA International Conference 2007.
Secure Cryptographic Workflow in the Standard Model.
INDOCRYPT 2006.
Efficient Identity-Based Key Encapsulation to Multiple Parties.
IMA International Conference 2005.
Other
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 (5), Miguel Ambrona, Joël Alwen, Afonso Arriaga (2), Paul Baecher, Manuel Barbosa (14), Balthazar Bauer (3), Kamel Bentahar, Jan Bobolz, Chris Brzuska (2), Aisling Connolly, Geoffroy Couteau, Jean Paul Degabriele, Yevgeniy Dodis, Jean-Charles Faugère, Marc Fischlin, Georg Fuchsbauer (2), Rosario Gennaro, S. Dov Gordon, Patrick Harasser (3), Dennis Hofheinz (3), Louiza Khati (2), Markulf Kohlweiss (2), Enrique Larraia, Benoît Libert, Mohammad Mahmoody, John Malone-Lee, Sogol Mazaheri (2), Arno Mittelbach (3), Adam O'Neill, Claudio Orlandi, Alain Passelègue, Kenneth G. Paterson (3), Ludovic Perret, Bertram Poettering, Gordon Procter, Elizabeth A. Quaglia, Răzvan Roşie, Yannick Seurin, Nigel P. Smart, Martijn Stam, Akira Takahashi, Stefano Tessaro (3), Damien Vergnaud (2), Bogdan Warinschi, Gaven J. Watson, and David A. Wilson.