# A Cross-Chain Solution to Connect Multiple DNS Blockchains in Consensus Roots System
## 1 Introduction  
With the Internet's widespread adoption, it has become integral to people's lives, serving as the primary platform for information exchange, entertainment, and business. In this digital era, the Domain Name System (DNS) has emerged as the primary means of connecting to the network [1], simplifying access. DNS facilitates the conversion of domain names to corresponding IP addresses, a crucial element in internet communication. However, traditional DNS resolution relies on a centralized system, where a single governing authority manages operations [2]. This centralized approach presents security risks, as a breach could disrupt the entire network, posing significant societal threats. Hence, recent efforts have explored decentralized DNS resolution methods to enhance network security and reliability. On 1 October 2016, the National Telecommunications and Information Administration (NTIA), a subsidiary of the US Department of Commerce, decided to transfer the management authority of the domain name resolution system DNS to the non-profit organization ICANN (Internet Corporation for Assigned Names and Numbers) [3]. This decision is an important milestone in the history of Internet development, marking that the Internet had officially entered the era of global governance, which means paying more attention to DNS security and sharing issues. In the past, the management authority of DNS was always owned by the US government, but this centralized management modeposed risks. For example, the US government may interfere with the Internet improperly for its own interests or the DNS system may be attacked, resulting in abnormal operation of the entire Internet. Therefore, transferring the management authority of DNS to ICANN can reduce the risks of a single management authority, and it can also protect the security and fairness of the global Internet. Blockchain, known for its secure distributed storage, addresses the centralized authority issues in DNS [4; 5]. Recent years have witnessed increased blockchain-based DNS proposals, aimed at either augmenting or replacing the centralized DNS while enhancing efficiency [6]. For instance, researchers from the City University of Macau and Guangzhou University introduced a decentralized consensus roots system, comprising global domain name root servers [7]. Using blockchain, this system ensures decentralized governance, and each region maintains an open \"local consensus system\". This forms a \"Federated roots\" system, enabling synchronous external domain name resolution among regions, even during Top-Level Domain (TLD) service interruptions, thus mitigating centralized internet risks. As shown in Figure 1, the consensus roots system based on blockchain faces many challenges. Different regions may use different types and versions of blockchains, which makes data exchange and interoperability difficult. Also, using one blockchain for domain name information sharing can affect system efficiency due to the slow transaction processing and the need for verification and recording by multiple nodes. Regions with sensitive or private domain name information may not want to store all data publicly on the same blockchain. A blockchain-based consensus roots system across multiple regions needs solutions for improving interoperability, for ensuring equal governance among different blockchains, and for optimizing system efficiency and performance. These goals are hard to achieve. To address the interconnection challenge in the consensus roots system, this study proposes a 1 + N cross-chain architecture that enables interoperability and synchronization among heterogeneous blockchains across different regions. The proposed scheme establishes a decentralized, tamper-resistant DNS resolution mechanism using cross-chain technology, ensuring fairness and security in domain name data sharing. By synchronizing only essential cross-chain information rather than all data, the approach enhances system scalability and mitigates the performance limitations of single-chain solutions.