Security Measures to Protect your AWS Simple Storage Service (S3)

Amazon S3 is a web storage service offered by Amazon. It provides customers with secure access to their data from anywhere at anytime. The service is designed to provide reliable storage and retrieval of large amounts of data. There are numerous ways to manage security for an S3 bucket. In this blog post we will take a look at these methods. Let’s start with defining objects.

What is S3 bucket object?

Amazon S3 organizes data into buckets and calls any content in it objects. An object is any type of file, such as a word document, a picture, or audio. While you upload a file to the S3 bucket, you can provide metadata with it and specify access rights of the file. By default, access to the data hosted in Amazon S3 is constrained; just the owners of the object and the bucket can access the Amazo S3 bucket resources, which is the AWS account.

S3 Bucket Protection

You can manage access to buckets and objects with various methods:

IAM policy

Using IAM trust policies in conjunction with resource policies, you may give fine-grained permission to other AWS customers and groups of IAM users to access your Amazon S3 resources using IAM policies. IAM rules are tied to customers, allowing for central control of access management for them.

Access Control Lists (ACL)

In Amazon S3, ACLs may be used to provide groups of users with read or write access rights in the bucket or object domain.

Bucket policy

Bucket policies control straightforward access to the S3 bucket. The bucket policy may be used to govern HTTP/HTTPS access, cryptographic configurations, and the originating IP address scope which are authorized to access S3 buckets and their contents.

You can allow or deny permissions to certain objects within a bucket. Policies may be applied to a single user, set of users, or Amazon S3 buckets. This allows for a centralized permission control mechanism. You may also allow users access inside your user account and other AWS accounts to your Amazon S3 objects with the help of bucket policies.

Block public access

If you activate prevent public access in the Bucket settings, any effort to allow public accessibility of items in the S3 bucket is refused. By modifying the public access settings for your account in the S3 management portal, you may establish block public access settings on a single S3 bucket or all S3 buckets in your AWS account.

S3 block public access options contains a number of things such as:

Publicly available: Anyone can list, write objects and has read and write privileges.

Objects can be made public: The bucket is not made publicly available; however, people with permissions can allow public access to specific objects.

NotPublic: Neither the bucket nor the objects contained within it are accessible to the public.

Query String Verification

S3 bucket also allows programmers to employ query string verification, which enables them to exchange Amazon S3 assets using URLs that are legitimate for a set amount of duration. Query string authentication is helpful for providing HTTP access to sites that would otherwise need authentication.

S3 analytics

This enables you to picture the access blueprint of your hosted S3 object data. Examine your S3 data by bucket, prefixes, metadata, as well as last access time.


As we have covered, we have a wide array of tools to secure our AWS S3 bucket and and objects. Take advantage of ACL, IAM rules, bucket policies, public availability options, query string verification and S3 analytics to improve protection of your S3 buckets.

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