Justin Y. Shi | Editor in Chief, IEEE BCTB 2025 | [email protected]

Message from Dr. Justin Y. Shi, Editor in Chief

By Chinnala Abhilash, Department of Computer Science and Engineering – Indian Institute of Technology Indore, India [email protected]

Slot-based consensus mechanisms have become popular in blockchain systems in improving scalability and security. However, current protocols often suffer from centralization risks, leader predictability like grinding attack, and lack of distinction between proposer and validator responsibilities. This paper presents a novel blockchain architecture that integrates Verifiable Random Function (VRF) for randomized validator committee selection, Verifiable Delay Function (VDF) for unbiased leader election , and Proof of History (PoH) for tamper-resistant block ordering. Each epoch consists of multiple time-bounded slots like Ethereum, with a unique leader proposing a block containing transactions and a randomly selected validation committee for each slot, which replays and voting on the block’s validity. Validators and leaders are strictly limited to their assigned slots, ensuring role isolation and minimizing the possibility of collusion . Our design enhances fairness, scalability, and accountability in block production and validation. We implement the protocol using Java, evaluating its throughput and consensus consistency under varying validator pool sizes. The results depicts secure block finality and low validation overhead by lightweight PoHbased consensus . We formally analyze the system’s security against manipulation, voting faults, and timing-based attacks, showing improved decentralization and resilience compared to existing slot-based Ethereum model. Index Terms—Verifiable Random Function (VRF), Verifiable Delay Function (VDF), Slot-Based Consensus, Decentralized Leader Election

Enhancing Smart Contract Security through Static Code Analysis

By Dmytro Khimchenko, Czech Technical University Ackee Blockchain Security Prague, [email protected], Czech Republic

Josef Gattermayer, Czech Technical University Ackee Blockchain Security Prague, [email protected], Czech Republic

This article presents a novel static analysis approach for enhancing Ethereum smart contract security through the Wake framework. Our implementation focuses on detecting “write-after-write” vulnerabilities—a critical issue where variables are overwritten before their values are utilized. The approach leverages the complementary relationship between Control Flow Graphs (CFGs) and Data Dependency Graphs (DDGs), enabling precise tracking of variable operations throughout code execution paths. By correlating in-edges (write operations) and out-edges (read operations) in the DDG with corresponding nodes in the CFG, the detector achieves significantly higher accuracy than existing solutions.
In our empirical evaluation, we compared our Wake-based detector against an equivalent implementation in Slither using both controlled test cases and real-world contracts. Results demonstrate that the Wake-based detector consistently achieves superior precision and substantially higher recall across all test scenarios. The F1-score of our implementation significantly outperforms Slither’s implementation in both experimental settings. These results demonstrate how leveraging graph-based program analysis techniques with precise variable operation tracking can dramatically improve vulnerability detection in smart contract security analysis.