AWS News Blog Amazon S3 Update – SigV2 Deprecation Period Extended & Modified Every request that you make to the Amazon S3 API must be signed to ensure that it is authentic. In the early days of AWS we used a signing model that is known as Signature Version 2, or SigV2 for short. Back in 2012, we announced SigV4, a more flexible signing method, and made it the sole signing method for all regions l