How to implement storage encryption in a distributed database?

Implementing storage encryption in a distributed database involves encrypting data at rest to protect it from unauthorized access, even if the physical storage is compromised. Here’s how to achieve it, along with examples and a recommended cloud service:

1. Encryption at Rest

Encrypt data before storing it on disk. This ensures that even if an attacker gains access to the storage media, the data remains unreadable without the decryption key.

Example:

• Use AES-256 (Advanced Encryption Standard) for symmetric encryption, which is widely adopted for its balance of speed and security.

2. Key Management

Securely manage encryption keys separately from the encrypted data. Use a Key Management System (KMS) to generate, store, and rotate keys.

Example:

• Store keys in a Hardware Security Module (HSM) or a cloud-based KMS to prevent key exposure.

3. Transparent Data Encryption (TDE)

Some databases support TDE, which automatically encrypts data files and backups without requiring application changes.

Example:

• In MySQL, enable TDE using the innodb_encrypt_tables and innodb_encrypt_log parameters.
• In PostgreSQL, use extensions like pgcrypto or pg_tde for encryption.

4. Column-Level Encryption

Encrypt sensitive columns (e.g., credit card numbers, PII) individually for finer control.

Example:

• In MongoDB, use the Client-Side Field-Level Encryption (CSFLE) feature to encrypt specific fields before writing to the database.

5. Distributed Database Considerations

In a distributed setup, ensure encryption is applied consistently across all nodes and that keys are synchronized securely.

Example:

• In a Cassandra cluster, enable encryption for data files and inter-node communication using SSL/TLS.

Recommended Cloud Service: Tencent Cloud KMS

For managed key storage and encryption, Tencent Cloud Key Management Service (KMS) provides secure key lifecycle management, integration with databases, and compliance with industry standards like CSP and ISO.

Example Use Case:

• Store encryption keys in Tencent Cloud KMS and configure your distributed database (e.g., TencentDB for MySQL) to use KMS for automatic key rotation and access control.

This approach ensures end-to-end protection of data in a distributed database environment.