This topic describes how to configure Transparent Data Encryption (TDE) for an ApsaraDB RDS for MySQL instance. You can use TDE to perform real-time I/O encryption and decryption on data files. Data is encrypted before it is written to a disk and is decrypted when it is read from a disk to the memory. After TDE is enabled for your RDS instance, the size of data files in the instance does not increase. You can use TDE without the need to modify the configurations of your application.

Prerequisites

  • Your RDS instance runs one of the following MySQL versions and RDS editions:
    • MySQL 8.0 (with a minor engine version of 20191015 or later) on RDS High-availability Edition with local SSDs
    • MySQL 5.7 (with a minor engine version of 20191015 or later) on RDS High-availability Edition with local SSDs
    • MySQL 5.6
    Note For more information about how to update the minor engine version of an RDS instance, see Update the minor engine version of an ApsaraDB RDS for MySQL instance.
  • Key Management Service (KMS) is activated. If KMS is not activated, you can activate KMS when you enable TDE.

Background information

TDE performs data-at-rest encryption at the database layer. This prevents potential attackers from bypassing the database to read sensitive information from storage. TDE encrypts sensitive information within tablespaces, on-disk data, and backup data. TDE also automatically decrypts the information and data to plaintext for applications and users that have passed database authentication. For operating system users who want to read sensitive information within tablespaces and unauthorized users who want to read backup data and on-disk data, TDE disallows them to access the plaintext information and data.

The key that is used for TDE is created and managed by Key Management Service (KMS). ApsaraDB RDS does not provide the key or certificates that are required for encryption. You must authorize ApsaraDB RDS to access KMS. This way, you can use an automatically generated key or a custom key.

Note After you enable TDE, the encryption algorithms vary based on MySQL versions. The following list describes the mappings between MySQL versions and encryption algorithms:
  • MySQL 8.0 and MySQL 5.7: AES_256_CBC
  • MySQL 5.6: AES_128_ECB

Usage notes

  • We recommend that you update the minor engine version of your RDS instance to the latest version to ensure the stability of the instance. If read-only RDS instances are attached to your RDS instance, we recommend that you update the minor engine versions of your RDS instance and all the read-only RDS instances to the latest version. For more information, see Update the minor engine version of an ApsaraDB RDS for MySQL instance.
  • When you enable TDE, your RDS instance restarts. As a result, a transient connection occurs. Proceed with caution. Before you enable TDE, we recommend that you make appropriate arrangements for your workloads based on your business requirements.
  • After you enable TDE, you cannot disable TDE.
  • After you enable TDE, you cannot change the key that is used for TDE.
  • After you enable TDE, you must decrypt the data on your RDS instance if you want to restore the data to an on-premises database. For more information, see the "Decrypt a table" section of this topic.
  • After you enable TDE, the CPU utilization of your RDS instance significantly increases.
  • If you use an existing custom key for TDE, take note of the following information:
    • If you disable the key, configure a plan to delete the key, or delete the key material, the key becomes unavailable.
    • If your RDS instance restarts after you revoke the key, your RDS instance becomes unavailable.
    • You must use an Alibaba Cloud account or an account to which the AliyunSTSAssumeRoleAccess policy is attached.
    Note For more information about KMS, see What is KMS?

Use an automatically generated key

  1. Access RDS Instances, select a region at the top, and then click the ID of the target RDS instance.
  2. In the left-side navigation pane, click Data Security.
  3. On the TDE tab, turn on TDE Status.
  4. In the dialog box that appears, select Use an Automatically Generated Key and click OK.

Use an existing custom key

  1. Access RDS Instances, select a region at the top, and then click the ID of the target RDS instance.
  2. In the left-side navigation pane, click Data Security.
  3. On the TDE tab, turn on TDE Status.
  4. In the dialog box that appears, select Use an Existing Custom Key and click OK.
    Note If you do not have a custom key, you can click go to the KMS console to create one. In the KMS console, you can create a key and import your own key material. For more information, see Create a CMK.

Encrypt a table

If you want to encrypt a table on an RDS instance, you must log on to the RDS instance and execute the following statements:

  • If your RDS instance runs MySQL 5.6, execute the following statement: 
    alter table <tablename> engine=innodb,block_format=encrypted;
  • If the RDS instance runs MySQL 5.7 or MySQL 8.0, execute the following statement: 
    alter table <tablename> encryption='Y';

Decrypt a table

If you want to decrypt a table on an RDS instance, you must log on to the RDS instance and execute the following statements:

  • If the RDS instance runs MySQL 5.6, execute the following statement: 
    alter table <tablename> engine=innodb,block_format=default;
  • If the RDS instance runs MySQL 5.7 or MySQL 8.0, execute the following statement: 
    alter table <tablename> encryption='N';

FAQ

  • After I enable TDE, can I use common database tools such as Navicat?

    Yes, after you enable TDE, you can use common database tools such as Navicat.

  • After I enable TDE, can I migrate data from my RDS instance to a different RDS instance?

    Yes, after you enable TDE, you can migrate data from your RDS instance to a different RDS instance.

  • After I enable TDE, why is my data still in plaintext?

    After you enable TDE, your data is stored in ciphertext. However, when the data is queried, it is decrypted and then loaded in plaintext to the memory. TDE encrypts backup files to prevent data leaks. Before you restore the data of your RDS instance from an encrypted backup file to your computer, you must decrypt the file. For more information, see the "Decrypt a table" section of this topic.

References

Configure TDE for an ApsaraDB RDS for SQL Server instance

Related operations

Operation Description
Enable TDE Enables TDE for an instance.