Signature Version 4 (SigV4) is the process of adding authentication information to AWS API requests sent by HTTP. For security, most requests to AWS must be signed with an access key. The access key consists of an access key ID and secret access key commonly referred to as your security credentials. You can find more about SigV4 in the official documentation.
Misc improvements.
BSD-3 license (https://opensource.org/licenses/BSD-3-Clause)