Comparison

The following table (Table 4.2) summarizes the different encryption options available in S3:

Table 4.2 – S3 encryption options compared

Bucket policy

Bucket policies are resource-based IAM policies that define explicit rules for access to S3 resources. These are essential for implementing fine-grained access control to your S3 buckets and objects. While identity-based IAM policies are attached to principals such as users and roles, bucket policies are attached directly to the bucket, providing a centralized way to manage permissions.

For advanced scenarios, bucket policies can be used in conjunction with other AWS services, such as AWS Organizations and SCPs, for even more granular control. For example, you can restrict S3 bucket access to certain VPCs or even specific IP ranges. This is particularly useful in hybrid cloud scenarios or when you need to enforce strict network segmentation for compliance reasons.

Bucket policies also allow for advanced features such as VPC endpoint policies, which can restrict access to a bucket to requests that come from a specific VPC endpoint. This is a powerful feature for limiting data exfiltration risks.

EBS volumes

While Amazon EBS serves as the go-to block storage service for EC2 instances, offering high performance and durability, this alone doesn’t constitute a comprehensive data protection strategy. Let’s dive into advanced techniques for securing data stored on EBS volumes.