The only reason for suggesting a block chain is that the information should be publicly available without having to visit a specific vendor's web site for confi

The only reason for suggesting a block chain is that the information should be publicly available without having to visit a specific vendor's web site for confirmation. But maybe it's not necessary. DNS Root Zones, for example, are publicly accessible and well managed (maybe not the registrars, but the registry) so perhaps a well-funded third party could establish a trusted, global, registry for supply chain Merkle Trees.