| In recent years,the number of smart contract applications in Ethereum has continued to increase,bringing huge economic benefits while also hiding huge security risks.Since blockchain data has the characteristics of immutability and decentralization,it is easy to cause blockchain data to be spread and attacked by malicious content.However,it is very difficult to attack the blockchain platform and requires considerable resources.On the contrary,the attack on the smart contract is relatively simple.When the smart contract is deployed and online,it cannot be modified.Once the security risk of the smart contract is discovered later,anyone can attack the security vulnerabilities in the contract and cannot take corresponding defense measures.Prevent the deterioration of security issues.How to detect contract vulnerabilities before smart contract deployment has become a concern of blockchain developers,so the research and application of smart contract vulnerability detection technology is of great significance.This paper analyzes the high-risk vulnerabilities in smart contracts,researches mainstream vulnerability detection technologies,and designs and develops a smart contract vulnerability detection system based on symbolic execution and feature code matching technologies.the detailed research content and innovation as follows:(1)Aiming at the problem of path traversal,a heuristic search algorithm shs-s is proposed to search the best traversal path,prune the path,and optimize the path recursively and cyclically to alleviate the impact of path explosion in the process of path traversal and effectively reduce the risk of path explosion.(2)Aiming at the problem of constraint solving,an improved scheme of comprehensive constraint solving optimization is proposed.The process of constraint solving,i.e.before solving,during solving and after solving,is divided into constraint branches,irrelevant constraint elimination,result cache and reuse,which effectively improves the operation efficiency of constraint solving.(3)Based on feature code matching and symbolic execution technology,a fully functional smart contract vulnerability detection system was designed and developed,which can complete the detection of common vulnerabilities such as smart contract code specification vulnerabilities,flushing vulnerabilities,and integer overflow vulnerabilities,while ensuring that new vulnerabilities appear The system can expand the scope of vulnerability detection in time,and has the advantages of high operating efficiency and strong scalability compared with other smart contract vulnerability detection tools. |
