Applied cryptography bridges the gap between abstract security definitions and
real-world deployable systems. Our research focuses on designing and implementing
efficient cryptographic solutions for privacy-sensitive applications, with a
particular specialisation in searchable encryption.
Searchable encryption (SSE/DSSE): efficient and privacy-preserving encrypted database queries.
Dynamic and conjunctive SSE schemes with strong forward and backward privacy.
Privacy-preserving computation: oblivious RAM (ORAM), garbled circuits, and secure function evaluation.
Encrypted graph analytics and privacy-preserving graph algorithms.
Zero-knowledge proofs and their application to authentication and verifiable computation.
Prototype implementations and performance evaluation of cryptographic protocols.
Post-Quantum Cryptography
This area investigates cryptographic primitives and systems believed to be secure
against both classical and quantum adversaries. We focus on the mathematical
foundations underpinning NIST-selected algorithms and emerging candidates, with
attention to both theoretical analysis and practical deployment.
Lattice-based cryptography: Learning With Errors (LWE), Ring-LWE, Module-LWE, and NTRU variants.
Code-based cryptography: McEliece, BIKE, HQC, and novel code families.
Hash-based signatures: SPHINCS+, XMSS, and stateless tree-based schemes.
Isogeny-based constructions and post-SIDH protocols.
Security proofs under the quantum random oracle model (QROM).
Post-quantum searchable encryption and dynamic symmetric searchable encryption (SSE).
Cryptanalytic assessments and parameter selection for deployed systems.
Quantum Cryptography
Quantum cryptography exploits the laws of quantum mechanics to provide
information-theoretic security guarantees impossible classically. Our work
investigates both theoretical underpinnings and practical implications for future
communication infrastructure.
Quantum key distribution (QKD): BB84, E91, continuous-variable QKD protocols.
Security proofs for quantum protocols in the composability framework.
Quantum random number generation and its role in cryptographic applications.
Device-independent cryptography and self-testing of quantum devices.
Quantum oblivious transfer, commitment, and secure computation.
Transition strategies from classical to quantum-safe communication channels.
Cloud Computing Security
As organisations increasingly outsource computation and data storage to cloud
platforms, ensuring confidentiality, integrity, and verifiability becomes critical.
QuRAC investigates principled cryptographic solutions to cloud security challenges
with a focus on practical deployability.
Secure outsourced computation: verifiable and privacy-preserving cloud services.
Encrypted database systems: verifiable query processing and integrity guarantees.
Searchable encryption for cloud-hosted databases with dynamic update support.
Data provenance and audit trails with cryptographic integrity.
Key management and access control in multi-tenant cloud environments.
Post-quantum migration strategies for cloud-based public-key infrastructure.
Blockchain and Consensus Security
Distributed ledger technologies present unique security challenges in the
post-quantum context. We study security foundations of blockchain platforms —
particularly Ethereum and its Layer-2 ecosystem — and design quantum-safe
alternatives to critical components.