Dear Kim and Natalie, Nice to meet you all.
We have done some research based on the block-certs in the last three month. Which we use a multi-signature scheme and a transaction information sharing model to make the project more secure and harder to forge.
You can read the document(the attachment) even it still has some problems, But the document’s main idea is right. It's wonderful that we can cooperate to make the block-certs better.
Download from here