Secure Database Exports & Encryption

TL;DR

Export sensitive database data securely by encrypting it at rest and in transit. Transform the data using secure methods, maintaining encryption throughout the process. Use strong keys, manage access carefully, and audit all operations.

1. Choose an Encryption Method

Select a robust encryption algorithm like AES-256. Avoid weaker algorithms. Consider these options:

• Database Native Encryption: Many databases (e.g., PostgreSQL, SQL Server) offer built-in encryption features. This is often the simplest approach.
• Transparent Data Encryption (TDE): Encrypts data at rest without application changes.
• Column-Level Encryption: Encrypt specific columns containing sensitive information.

2. Exporting the Database

The method depends on your database system, but always prioritise secure transfer:

1. Use Secure Protocols: When exporting via command line tools (e.g., pg_dump for PostgreSQL, mysqldump for MySQL), use SSH or TLS/SSL to encrypt the connection.
2. Encrypt the Export File: Even if using a secure protocol, encrypt the resulting dump file itself. Use a tool like OpenSSL:

   openssl enc -aes-256-cbc -salt -in database_dump.sql -out database_dump.enc -k "your_strong_password"

3. Avoid Plain Text Exports: Never export data in plain text if it contains sensitive information.

3. Transforming the Data

Transforming encrypted data requires careful planning. Avoid decrypting and re-encrypting unnecessarily.

1. Use Secure Transformation Tools: If possible, use tools that can operate directly on encrypted data without decryption.
2. In-Memory Encryption: For transformations requiring decryption, perform the operation in memory only. Avoid writing decrypted data to disk.
3. Secure Scripting Environments: Use secure scripting languages and environments (e.g., Python with cryptography libraries) to minimise risks of exposure during transformation.

4. Key Management

Strong key management is crucial:

• Generate Strong Keys: Use a cryptographically secure random number generator to create strong encryption keys.
• Store Keys Securely: Never store keys in the same location as the encrypted data. Use a dedicated Key Management System (KMS) or Hardware Security Module (HSM).
• Key Rotation: Regularly rotate your encryption keys to reduce the impact of potential compromises.

5. Access Control

Restrict access to both the encrypted data and the encryption keys:

• Principle of Least Privilege: Grant users only the minimum necessary permissions to access data and keys.
• Multi-Factor Authentication (MFA): Enforce MFA for all accounts with access to sensitive data or key management systems.
• Regular Access Reviews: Periodically review user access rights to ensure they remain appropriate.

6. Auditing and Monitoring

Track all operations related to the database export, transformation, and encryption:

• Log All Accesses: Log all attempts to access encrypted data or keys.
• Monitor for Suspicious Activity: Implement monitoring systems to detect unusual patterns of activity that could indicate a security breach.
• Regular Security Audits: Conduct regular security audits to identify and address potential vulnerabilities.

7. Example Scenario (PostgreSQL)

Exporting and encrypting with pg_dump:

1. Dump the database using SSH tunnel for secure transfer:

ssh user@host "pg_dump -U postgres -d your_database > database.sql"

2. Encrypt the dump file:

openssl enc -aes-256-cbc -salt -in database.sql -out database.enc -k "your_strong_password"

3. Securely store database.enc and manage the password.