The Design And Implementation Of Domain Name System Via Blockchain Technique

Domain Name System(DNS)is an important infrastructure of the Internet,which maps memorable domain names to the numerical IP address,giving people easier access to the Internet.Currently,DNS is distributed structure with a dispatch center,the Internet Corporation for Assigned Names and Numbers(ICANN),who is responsible for scheduling and managing the system,ICANN as a centralized organization completely controls the allocation and resolution of domain names,which exists serious risks of power abuse and single point of failure.Besides,current DNS is vulnerable to cache poisoning,vanishing risk,blinding risk and so on.Blockchain is a trusted distributed database that stores records in chronological order,and the blockchain protocol maintains the distributed database in a decentralized network,which has the characteristics of decentralization,security,credibility,non-tampering,and common maintenance.In view of the above problems of DNS,this paper proposes to use the blockchain technique to reconstruct the domain name service system.In view of the centralization problem of the current domain name system,this paper analyzes the different characteristics of the three types of blockchain in detail and adopts the form of consortium chain,which can not only manage the top-level domain to a certain degree,but also allow ordinary nodes to join freely to provide a complete domain name service,the multi-centered structure of the consortium chain can effectively avoid the risk of power abuse and single point of failure.In order to allow more nodes to join and provide domain name services better,this paper designs three different nodes: consortium nodes,ordinary nodes,and light nodes,where ordinary nodes and light nodes can join freely without permission.In order to resolve the contradiction between the low blockchain throughput and the high performance requirements of the domain name system,this paper solves this problem in two aspects by combining multi-chain technique and sharding protocol.In order to solve the problem of insufficient scalability of the blockchain's structure,this paper uses a multi-chain structure,that is,a main chain and multiple sub-chains.The sub-chain maintains the same block height as the main chain and establishes a link through hashing.Structural scalability can be achieved by legally adding sub-chains.In view of the problem of insufficient throughput caused by all nodes in the blockchain competing for the sametransactions,this paper introduces sharding protocol to divide a large number of ordianry nodes into multiple shards securely and randomly,and the consensus of the requests on different sub-chains is processed parallel by multiple shards,which can scale throughput of the system from constant level to linear level compared to other blockchain domain name systems,It has been proved by experiments that it almost satisfies the scalability of O(n/loglogn).Since the consortium nodes in the consortium chain often need to vote on the request of the top-level domain,in order to guarantee the identity anonymity and voting fairness of these consortium nodes,this paper leads into a linkable ring signature technique.Finally,this paper uses Memory-based database as a cache for hotspot data to achieve 100,000 levels of concurrency.A combination of these techniques enables a secure,scalable and high-throughput domain name system in this paper.