Strengthening Web3 Data Confidentiality Through Blockchain-Enabled Multifactor Authentication: A Comparative Security Evaluation

Developments of Web 3.0 technologies present vital problems regarding data confidentiality, authentication of users and their privacy in decentralised systems. The traditional multifactor authentication (MFA) systems have been effective when deployed in Web2 environments but have failed in protecting sensitive information in the decentralised environment because they use centralised servers and are also dependent on static security factors. The paper explores the concept of multifactor authentication that is based on blockchain technology as the effective method of improving the use of data confidentiality in Web3. A blockchain-augmented MFA infrastructure was created on the basis of an Ethereum smart contract, decentralised storage, and biometric data that were cryptographically encrypted. Simulation demonstrated significant increases in security relative to conventional MFA systems, a significant drop in the probability of breaching (0.0270 to 0.0040), an improvement in the entropies, a decrease in the likelihood of session hijacking, and limited mutual information leakage. Also, the blockchain-based system becomes more resistant to Man-in-the-Middle (MITM) and phishing attacks, mitigating them by about 60 per cent and 50 per cent success rates, respectively. Whereas the blockchain MFA made some minor sacrifices in latency and computation cost in the course of authentication, such a trade of costs is productive in the Web3 environment where security and data integrity remain of utmost importance. The study could be useful to developers, security practitioners and policymakers who intend to develop more secure, scalable, and user-centric authentication mechanisms in decentralised apps. As a potential improvement, it is suggested that future research should implement the aspect of consensus optimisation and Layer-2 to increase the efficiency and scalability further.