I worry about the ability to fabricate false evidence. To prove authenticity of facts, we may need to build a trail of evidence for non-repudiation. This dove

I worry about the ability to fabricate false evidence. To prove authenticity of facts, we may need to build a trail of evidence for non-repudiation. This dovetails somewhat with reputation. Being able to prove authenticity of a document, audio, or video clip as of a certain date (not generated after the fact) is one useful application (side effect?) of blockchain technology.