Blockchains & System Security @ FIT

Key research areas include:

• Scalability and Security in Blockchain Consensus Protocols: Investigating Directed Acyclic Graph (DAG)-based consensus protocols (e.g., PHANTOM, GHOSTDAG, SPECTRE, Inclusive, Prism) to enhance parallel transaction processing and scalability. The group has pioneered the identification of incentive-driven attacks that undermine random transaction selection, proposing novel protection mechanisms to ensure fair and efficient blockchain operation, as demonstrated in large-scale simulations and game-theoretic analyses. Other work includes empirical security analyses of Secret Single Leader Election (SSLE) mechanisms in Ethereum's Proof-of-Stake (PoS), such as Whisk and homomorphic sortition, under denial-of-service (DoS) on the leader and censorship attacks. This research evaluates their effectiveness against targeted and coordinated adversarial strategies, highlighting trade-offs in protection, scalability, and practicality for large validator sets.

• Novel Consensus Mechanisms: Exploring innovative protocols beyond traditional Proof-of-Work (PoW) and Proof-of-Stake (PoS), such as Proof-of-Useful-Work (PoUW), which redirects computational efforts toward solving real-world problems (e.g., scientific computations) to minimize energy waste while maintaining security. The group is also advancing PoUW integrated with zk-SNARK proofs for mining, where the "useful work" involves generating verifiable zero-knowledge proofs for privacy-preserving applications. Additionally, research on Proof-of-Social-Capital (PoSC) leverages social interactions, trust, and influence as non-transferable staking resources to promote fairness, decentralization, and privacy in consensus, replacing traditional stake with social capital metrics in privacy-preserving designs.

• Blockchain-Based Authentication: Developing secure authentication schemes, such as SmartOTPS - the first one-time password (OTP) scheme for smart contract wallets - ensuring robust user access control in decentralized environments. The group has also introduced SNARKlet, a novel approach to mobile wallet synchronization that eliminates reliance on trusted servers while minimizing storage and bandwidth overhead.

• Central Bank Digital Currency (CBDC): Exploring secure architectures for CBDC, focusing on scalability, privacy, and resistance to adversarial attacks.

• Decentralized Identity and Privacy: Designing privacy-preserving decentralized identity systems and trust/reputation models to secure user interactions in blockchain ecosystems.

• System Security for Decentralized Applications: Addressing vulnerabilities in blockchain infrastructure, including cryptocurrency wallet security, fee-redistribution smart contracts to mitigate undercutting attacks, and adversarial resilience in distributed systems.