Blockchains can be public or private (i.e. restricted access). In this case, the latter would be appropriate. There are also ways of signing records to establis

Blockchains can be public or private (i.e. restricted access). In this case, the latter would be appropriate. There are also ways of signing records to establish that a known company produced them. The idea behind using blockchain for tracking provenance is that you can check if a widget with unique serial number number X has been produced, who currently possesses it, and whether it has already been used. It would also be possible for each manufacturer to maintain their own record, so blockchain is not the only solution, but it is a fairly good fit to this particular problem. As with manufacturers maintaining ownership records, it cannot absolutely prevent a counterfeit part being used, but since the part would have to come from the company who was the last holder of record for a specific genuine part, and the record for that genuine part would be marked as "consumed", normally there would be no financial motive to supply a counterfeit. (Supply to Russia might be a an exception).