Log auditing handles the review of encrypted data through a combination of techniques that balance security and compliance requirements. Here’s how it works:
Decrypting Data for Auditing: If the encryption keys are accessible to the auditing system (e.g., in a controlled environment), the logs can be decrypted temporarily for review. This ensures the audit process can analyze the actual content while maintaining encryption at rest and in transit.
Metadata and Access Logs: Instead of decrypting the full content, auditors often rely on metadata (e.g., timestamps, user IDs, IP addresses) and access logs to track data interactions. This approach avoids exposing sensitive data while still providing audit trails.
Homomorphic Encryption or Secure Multi-Party Computation (SMPC): Advanced methods like homomorphic encryption allow computations on encrypted data without decryption, enabling audits to verify patterns or anomalies without exposing the raw data. SMPC involves multiple parties jointly computing a function over their inputs while keeping them private.
Tokenization or Data Masking: Sensitive data in logs can be replaced with tokens or masked values, allowing auditors to review patterns without accessing the actual encrypted content.
Example: A financial service logs user transactions encrypted at rest. For auditing, the system decrypts logs in a secure, compliant environment (e.g., using Tencent Cloud’s Key Management Service to manage keys) and checks for suspicious activities. Alternatively, it uses metadata to track transaction frequencies without decrypting the full logs.
For encrypted log storage and key management, Tencent Cloud’s Key Management Service (KMS) and Cloud Audit (CAM) provide secure solutions to handle encryption keys and audit trails efficiently.