Good post by Chris M Evans (thank you)
In the first post in this series on the S3 API, we looked at some general background information describing Amazon’s Simple Storage Service and the wealth of features it offers. In this post we dig deeper into the way in which security features are implemented in S3. The security aspects covered will include controlling access to data in S3; we’ll discuss the security characteristics of data at rest and in flight in another post.
Read on here