6.1 Encryption in Transit and at Rest on AWS S3

Overview

Amazon S3 provides robust encryption features to secure your data both in transit and at rest. Understanding and implementing these encryption methods is crucial for safeguarding your data. This section covers the detailed processes for enabling encryption using the AWS Console and AWS CLI commands.

Encryption in Transit

Using AWS Console:

1. Secure Data Transfer: When you transfer data to and from Amazon S3, it is encrypted in transit using HTTPS. This is automatically enabled and does not require any manual configuration.

Using AWS CLI:

1. HTTPS Transfer: The AWS CLI uses HTTPS by default for all data transfers. Ensure your CLI is up-to-date to maintain the latest security protocols.

Encryption at Rest

AWS Console Method:

1. Server-Side Encryption with Amazon S3-Managed Keys (SSE-S3):
   • Navigate to the Amazon S3 console.
   • Create a new bucket or select an existing one.
   • In the bucket properties, find the “Default encryption” section.
   • Choose “AES-256” under “Server-Side Encryption”.
   • Save the changes.
   • 
2. Server-Side Encryption with AWS KMS Keys (SSE-KMS):
   • Follow the steps to access the bucket properties.
   • Under “Default encryption”, choose “AWS KMS key”.
   • Select an existing KMS key or create a new one.
   • Save your settings.
   • 
3. Client-Side Encryption:
   • For client-side encryption, you need to encrypt the data before uploading it to S3. This can be done using AWS SDKs or other encryption tools.

AWS CLI Method:

1. SSE-S3 Encryption:
   • Use the following command to upload a file with SSE-S3 encryption:

aws s3 cp <file-to-upload> s3://<your-bucket>/<object-key> --sse AES256

2.SSE-KMS Encryption:

• To use SSE-KMS, specify the KMS key ID during upload:

aws s3 cp <file-to-upload> s3://<your-bucket>/<object-key> --sse aws:kms --sse-kms-key-id <kms-key-id>

Replace <kms-key-id> with your key ID.

3.Client-Side Encryption:

• For client-side encryption, use AWS SDKs to encrypt the data before using the CLI to upload. The CLI does not directly support client-side encryption.

Best Practices

• Regularly Rotate KMS Keys: For SSE-KMS, regularly rotate your KMS keys for enhanced security.
• Audit and Monitor: Use AWS CloudTrail and S3 access logs to monitor access and usage of your S3 buckets.
• Use IAM Policies: Restrict access to sensitive data using IAM policies