Configuring services to activate encryption of data at rest (for example, Amazon S3, Amazon RDS, DynamoDB, Amazon Simple Queue Service [Amazon SQS], Amazon EBS, Amazon EFS)

What are the steps required to enable server-side encryption for an Amazon S3 bucket?

To enable server-side encryption for an Amazon S3 bucket, you need to:

• Open the Amazon S3 console and navigate to the bucket.
• Go to the “Properties” section.
• Click on “Default encryption.”
• Choose either AES-256 or AWS KMS encryption.
• If using AWS KMS, select a KMS master key.
• Save the settings.

This ensures that all new objects uploaded to the bucket will be encrypted at rest.

When enabling encryption at rest for Amazon RDS, what key management options do you have?

For Amazon RDS, you can encrypt your instances using:

• AWS Key Management Service (AWS KMS) for managing the encryption keys.
• You can opt to use a default AWS managed key or create a new customer managed key in KMS.

Encryption must be defined at the creation of the RDS instance; it cannot be applied to an already running instance without migrating to a new, encrypted instance.

Can you explain how encryption at rest is achieved for Amazon DynamoDB and what key management options are available?

Amazon DynamoDB supports encryption at rest using AWS managed keys by default, which requires no additional setup. If more control over the encryption keys is required, you can opt for customer managed keys using AWS Key Management Service (KMS). You can enable encryption when creating a new table by setting the “SSESpecification” attribute to true and selecting a KMS master key.

When configuring Amazon Simple Queue Service (SQS), how can you ensure that the messages at rest are encrypted?

To encrypt messages at rest in Amazon SQS:

• Open the SQS console and create a new queue or select an existing queue.
• Under “Queue Actions,” choose “Configure Queue.”
• Scroll to the “Encryption” section.
• Check “SSE” to enable server-side encryption.
• Choose an AWS managed key or select a customer managed key from AWS KMS.
• Save the changes.

By default, SQS uses an AWS managed CMK, but you can specify a customer managed CMK for more granular control.

How can you enable encryption for an Amazon Elastic Block Store (EBS) volume, and what are your options for managing the keys?

For Amazon EBS:

• Encryption can be enabled during the creation of a new volume by checking “Encrypt this volume” and selecting a KMS key.
• AWS managed keys can be used, or you can choose a customer managed key in KMS.
• Existing unencrypted volumes can be encrypted by creating a snapshot, then encrypting the snapshot and creating a new volume from the encrypted snapshot.

Describe the process to encrypt data at rest in Amazon Elastic File System (EFS)?

Amazon EFS encryption at rest can be enabled during the file system creation process:

• From the EFS console, select “Create file system.”
• In the “Add tags and optional settings” step, enable the “Encrypt this file system” option.
• Choose either the default AWS managed key for EFS or a customer managed key from KMS.
• Proceed to create the file system.

Encryption and key selection must be specified at the time of file system creation and cannot be added or changed later.

Is it possible to use customer managed keys for encryption with Amazon S3, and if so, what steps must be taken to use them?

Yes, Amazon S3 allows the use of customer managed keys through AWS KMS. To use customer managed keys:

• When enabling bucket encryption, choose “AWS KMS” as the encryption method.
• Select either an existing customer managed key or create a new one.
• Apply the changes to set up the bucket to use the customer managed key for encryption.

This choice provides additional control over key rotation, usage policies, and access controls.

Explain how you can verify if server-side encryption is enabled for an Amazon S3 object?

To verify server-side encryption for an S3 object:

• Navigate to the S3 console and select the bucket.
• Click on the object, then click the “Properties” tab.
• Look for the “Server-Side Encryption” section.
• The encryption status will indicate if the object is encrypted and the type of key used.

The object metadata will display encryption information, including whether an AWS KMS key or an S3 managed key is used.

What are the considerations when enabling encryption at rest for Amazon RDS with respect to performance and availability?

When enabling encryption at rest for Amazon RDS:

• Keep in mind there can be a minor performance overhead.
• Snapshots of encrypted databases are also encrypted, and any replicas will inherit encryption.
• Performance overhead is generally minimal but should be performance-tested for highly sensitive workloads.
• During periods of key rotation or if KMS is unavailable, access to encrypted data may be affected.

Consider these factors during planning, especially for high-availability and high-performance applications.

How would you approach migrating an existing DynamoDB table to use customer managed keys for encryption at rest?

Migrating an existing DynamoDB table to use customer managed keys involves:

• Creating an on-demand backup of the current table.
• Restoring the backup to a new table directly, with encryption at rest using the desired customer managed key.
• Updating applications and access policies to point to the new table, then decommissioning the old table.

This approach limits downtime and ensures a smooth transition to the new encryption configuration.