Appendix b: Authenticating requests (AWS signature version 2) - Amazon Simple Storage Service

This guide is no longer being updated. For current information and instructions, see the new Amazon S3 User Guide.

Appendix b: Authenticating requests (AWS signature version 2)

Important

This section describes how to authenticate requests using AWS Signature Version 2. Signature Version 2 is being turned off (deprecated), Amazon S3 will only accept API requests that are signed using Signature Version 4. For more information, see AWS Signature Version 2 Turned Off (Deprecated) for Amazon S3

Signature Version 4 is supported in all AWS Regions, and it is the only version that is supported for new Regions. For more information, see Authenticating Requests (AWS Signature Version 4) in the Amazon Simple Storage Service API Reference.

Amazon S3 offers you the ability to identify what API signature version was used to sign a request. It is important to identify if any of your workflows are utilizing Signature Version 2 signing and upgrading them to use Signature Version 4 to prevent impact to your business.