Technical Team/Use Cases/2.0/Check to see if the SPDX data provided matches the files provided and is trustworthy and most current for package

1. Title: Check to see if the SPDX data provided matches the files provided
2. Primary Actor: Downstream consumer of a package
3. Goal in Context: Verify that the license obligations for code provided by the upstream supplier matches the licensing information provided by the supplier
4. Stakeholders and Interests:
1. Upstream Supplier:
1. Express the contents of the delivered software and the license obligations in a manner which can be easily verified by the consumer
2. Downstream Consumer:
1. Verify the files match the description provided
2. Verify the origin of the files match
3. Verify the license obligations match
4. Provide the verified information to further downstream consumers
5. Preconditions:
1. Upstream provider provides an SPDX file along with the package 
6. Main Success Senario:
1. Supplier provides package and SPDX file.
2. Consumer runs runs file checksums against received files and compares to the SPDX file to validate file origin.
3. Consumer compares SPDX author and reviewer information and compares to a "trusted" list of authors.  Reviewer and supplier information is confirmed by verifying their signatures. (signing)
4. Consumer searches for any later revisions of the SPDX file which may contain corrections.
5. Consumer runs independent tools verifying information.  If any corrections are required, an updated SPDX file is produced and sent back to the supplier for comment.
7. Failed End Condition: No SPDX file provided.  No signatures for author and/or reviewers.  Internally inconsistent SPDX file.
8. Trigger:
   1. Delivery of a software package
9. Notes:  The scenerio could work without an initial SPDX file if all of the information is provided in a different format.  In this scenario, an SPDX file would be created as an output and the input pre-conditions would be essentially all of the required fields of the SPDX document.