# CrossDeFi: A Novel Cross-Chain Communication Protocol
## 2 Literature Survey
### Finality Guarantee in Cross-Chain Solutions  
This segment reviews various protocols developed to ensure transaction finality in cross-chain operations, crucial for preventing issues like double-spending. The work in [50] introduces an atomic swap cross-chain protocol that relies on a hashed timelock mechanism, a foundational approach for secure asset transfers. Extending this concept, a hash-locking-based multi-party protocol in [51] aims to refine asset transfer and user settlement across blockchains, through enhanced atomic swaps. InterTrust [52] offers an interoperable blockchain architecture that not only promises interoperability but also instills trustworthiness between diverse blockchains. It integrateswith conventional blockchains through an atomic cross-chain communication strategy known as the agnostic protocol, aimed at broad adoption. A new consensus model, multi-tokens proof-of-stake (MPoS) introduced in [53] attempts to fortify the role of token networks in cross-chain environments and significantly boost user engagement on blockchain networks. CrossLedger [54] proposes a strategy to allow more precise asset transfers across multiple blockchains, focusing on security against threats such as double-spending, liveness, and Sybil attacks. XCC [55], an extension of XCLAIM [56], reduces required collateral through periodic and time-locked commitments, allowing fractional collateralization while maintaining security. However, this approach struggles with slow transaction speeds and higher costs due to ineffective bridge strategy considerations. Further, the work in [57] proposes a main-sub-chain architecture to enhance cross-chain protocols. A cross-chain pathfinding solution in [58] develops a structure utilizing various bridge types to streamline asset transfers. In contrast, a protocol in [59] that allows asset reusability across blockchains suffers from failure in ensuring transaction finality, leading to potential double-spending. Other innovative approaches include a proof-of-burn protocol [60], which, despite its novelty, does not address decentralized finality and transfer confirmations--key for DeFi systems. The work in [61] proposes a burn-to-claim asset transfer protocol. An AucSwap has been introduced in [62] in which an auction process is defined through a cross-blockchain token transfer protocol. Particularly, it enables asset transfer across multiple blockchains by leveraging the Vickery auction process and atomic swap technology. However, it cannot accomplish more interoperability in financial applications. The works [63; 64] introduced strategies to realize the cross-blockchain transfers among the blockchain consensus effectively. Similarly, the work in [65] verifies transaction inclusions through blockchain consensus. A notable approach in [66] employs zero-knowledge proofs for transaction verification, though its reliance on a specialized sidechain strategy raises practical implementation challenges. Despite these advancements, decentralized asset transfer mechanisms [67] still struggle with ensuring finality, an issue somewhat addressed by a new transfer confirmation model in [68], which integrates oracles to bolster transaction security, albeit at a cost. Terra once aimed to revolutionize cross-chain interoperability with its UST stablecoin, providing stable and scalable financial operations. Despite its ambitious goals, the platform faced significant challenges, leading to its collapse, as noted in [69]. Further, the transition from Bitcoin to more scalable solutions like Solana highlights innovations in blockchain architectures that significantly enhance performance for enterprise applications, as detailed in [70]. Lastly, the study in [71] offers an in-depth analysis of the Avalanche consensus protocol, which improves upon traditional consensus mechanisms by utilizing randomized processes to ensure robust and efficient cross-chain transactions.