Cross-chain bridges are essential for enabling interoperability between diverse blockchain networks. At the same time, these technologies have introduced new avenues for illicit financial activity, such as chain-hopping, a method used to obscure transactional provenance by rapidly transferring assets across multiple chains. This study analyzes cross-chain token flows on the Wormhole bridge, focusing specifically on identifying suspicious token transfer patterns. We propose a methodology inspired by state-of-the-art anomaly detection techniques to identify and examine suspicious transaction patterns. Our findings provide valuable insights into cross-chain analysis and lay the groundwork for developing monitoring systems that can detect and analyze illicit behavior within cross-chain ecosystems.

Smart contracts are a key part of blockchain applications, and attackers can exploit them to manipulate contract behaviour or steal assets. Smart contracts often contain security vulnerabilities, either accidentally introduced by developers or due to flawed business logic. In this paper, we focus on finding an optimal Machine Learning based framework for detecting vulnerable smart contracts by analysing the smart contracts as embedding vectors. CodeBERT, a pre-trained transformer model, is used for feature extraction in the proposed framework. The framework has shown approximately 97% accuracy in detecting smart contracts that contain various vulnerabilities. Additionally, the research explores the performance of CodeBERT variants for this task. The results of the experiments have proven the favourability of this framework in detecting vulnerable smart contracts.

Blockchain Layer 2 solutions share the goal of moving computational processes and data off-chain. Along with modular design, they are becoming the new norm for blockchain scalability solutions. These approaches provide additional layers built on top of Layer 1 to process transactions more efficiently, relieving congestion on Layer 1. However, within the modular architecture of Layer 2, the data layer introduces trade-offs. One of these trade-offs involves the reliance on third-party decentralized storage services for data availability. These third-party decentralized storage services, while providing benefits for data availability, also introduce potential risks and dependencies. Users may have concerns about data availability, reliability, and security when relying on external storage providers. DePIN leverages blockchain rewards to incentivize the development of physical infrastructure networks. These networks could potentially provide data availability services for blockchain networks. By integrating physical infrastructure with blockchain technology, DePINs can offer reliable and secure data storage solutions that are decentralized and resistant to censorship or manipulation. This paper introduces the concept of using DePIN for the data availability layer in modular blockchain systems. It begins by reviewing the Layer 2 ecosystem and its limitations. The proposed concept could serve as motivation for further research into DePIN-based data layers for blockchain systems.

With hindsight, the role of a currency is to facilitate trade. Every sovereign nation manages its currency through a public institution called central bank - solely responsible for supply of currency. Central banks exert their responsibilities as a response to the global and local economic conditions. There is empirical evidence of central banks failing to stop the rout of their respective currencies; thus, losing the trust of their citizens. Central banks act as a custodian of trust. Given the politico-legal framework under which the central banks exist and operate, there exists a room for policy-making that affects financial worth of an individual and in turn of a nation - thus highlighting the role of transparency in the discretionary powers of a central bank. In the recent past, the technological innovations from information technology have helped central banks to introduce digital currency; thus, cutting costs in management of currency and bringing speed in its movement. This technological evolution also brought in privacy concerns while checking the double-spend problem. Blockchain based cryptocurrency has addressed the double-spend problem in digital currency but introduced itself as a global open currency where role of central bank is done by an algorithm.In the long and eventful evolution of currency we have come to a stage where one needs to reconsider the key decisions from the past that influenced the evolution of currency. In this paper, we discuss the key requirements in designing a CBDC and the challenges/limitations it faces.

Blockchain technology is becoming a promising technological solution for enterprise applications with the rise of interoperable solutions. A cross-chain architecture facilitates interoperability, thus improves its chain efficiency, reduces fragmentation, and allows users and features to flow more freely across multiple blockchains. However, enabling interoperability in silo networks will make a significant functional trade-off on the security and performance of the system. This paper review trade-offs in blockchain technologies related to interoperability.

The future of multi-blockchain architecture depends on the emergence of new protocols that achieve communication between trustless cross-chain participants. However, interoperability between blockchains remains an open problem. Existing approaches provide integration through solutions using a middleware system, which makes it harder to gain confidence mainly in terms of security and correctness of the process. A cross-chain protocol needs to provide a self-verifiable state-proof that embeds trust in the transfer process. We propose a Burn-to-Claim cross-chain protocol to seamlessly exchange assets between networks. Our scheme transfers assets from one blockchain system to another in a way that the asset is burned from the source blockchain and claimed on the destination blockchain. Our mechanism employs combinations of crypto mechanisms such as digital signatures and time lock to operate the protocol in a distributed manner. We provide an analysis which proves that our cross-chain protocol transfers assets correctly and securely.