What CloudTrail feature helps protect logs from tampering and unauthorized access?

CloudTrail log file validation is the feature designed to help protect logs from tampering and unauthorized access. This feature enhances the security of AWS CloudTrail by ensuring the integrity of log files. When log file validation is enabled, a cryptographic hash is created for each log file, allowing users to verify that the logs have not been altered after they were written.

Validation works by comparing the hash of the log files stored in Amazon S3 with the hashes contained in the corresponding validation files. If these hashes match, it confirms that the logs are intact and have not been tampered with, providing a strong assurance that the logging data remains trustworthy.

This level of protection is crucial for compliance and security monitoring, making it easier to audit activities within an AWS environment and respond to potential security incidents by establishing an immutable log of events.