BCALS: Blockchain-based secure log management system for cloud computing

A computing environment requires a robust and comprehensive process to track and document user activities to uphold confidence in the system. Audit logs are used for this purpose to monitor the actions of administrators and users. However, these logs are vulnerable to multidimensional attacks, including modification of logs, erasability of logs, and privacy of the user. Since administrators have unprecedented access to these logs, they can modify, delete, and even destroy them. Securing these logs against malicious activities is the prime requirement of audit log management. Existing schemes have several limitations, including immutability, computational expensiveness, missing semantics, and are not verifiable. Various schemes have been proposed for this purpose, but a standard method is required to structure heterogeneous logs and their security semantically. To cope with these limitations, in this paper, we propose a Log Management System using blockchain. The proposed system will ensure audit logs' security, which will eventually strengthen users' trust in the computing environment and make it unbreachable even by the administrators. It has been evinced that our model performed better in terms of performance and features already mentioned when compared with existing schemes.