A Fuzzy AHP-based trust management mechanism for self-sovereign identity in the metaverse

Self-sovereign identity (SSI) technology has advantages and potential for application in the metaverse. However, the decentralization and anonymous interaction of SSI create convenience for malicious attacks, frauds, and conspiracies in the metaverse. It leads to various trust risks and threats to the meta-universe system. To address these challenges, we analyze the risks of SSI systems and constructed a reputation index system. Moreover, we propose a blockchain-based reputation management framework (BBRMF), which can constrain users from engaging in illegal activities such as forgery, fraud, and conspiracy, thereby guaranteeing the security and trustworthiness of the entities involved in the metaverse. In BBRMF, we constructed a reputation evaluation model based on fuzzy analytical hierarchy process (FAHP) to assess the user’s reputation in three dimensions: reliability, trustworthiness and security. To motivate users to accumulate more positive reputation, we set the user’s reputation score into a reputation credential in the form of non-fungible token (NFT), through which users can obtain more benefits and opportunities. Finally, we calculated the reputation value of SSI related entities from multiple perspectives through simulation experiments and comparative analysis. The feasibility of the proposed method is verified, and it is proved that it can effectively resist the interference and attack of malicious scoring nodes. Moreover, the scheme adopts multi-dimensional evaluation indexes and behavioral feature values, which significantly improves the comprehensiveness and accuracy of the reputation assessment. Meanwhile, the weights of the evaluation indexes are derived through objective calculation, ensuring the fairness of the evaluation results, and improving the credibility and repeatability of the reputation assessment.