> I don't think most people would agree with such a radical change.

Sure, the anti-slavery faction of the Republican party were called the "Radical Republicans" for a reason. I'm perfectly OK being the only person on earth that believes something.

Don't take refuge in the false security of consensus.

As another commenter mentioned, if you want to prove you are the producer of a good/service, you can find invent some way to do that, but it's on you.

Or some startup could invent a verification method and sell it (as a service) ..

As an aside, I wonder to what extent trademark laws could be made obsolete through technical means (using cryptography for example). Pfizer could cryptographically sign its labels. The problem is that counterfeiters could still copy labels from existing products. Maybe Pfizer could use a distributed ledger (e.g. Bitcoin) to prove the authenticity of its products?

When Pfizer sells a product to a distributor, said distributor would require Pfizer to send a tiny transaction to their address.

  Known Pfizer address associated with product -> Distributor's address 

When the distributor sells the product to a retail shop, the retail shop could verify the product's authenticity by requiring the distributor to reveal an address that can be linked up to Pfizer's "known address associated with product".

As part of the purchase process, the retail shop would in turn require the distributor to send a transaction from said address to their address so that they can in turn prove authenticity to their customers and so on. A valid transaction should spend the full amount of the seller's address (e.g. 1 satoshi) so that there is only one possible path from Pfizer's address to the final owner of the product.

  Known Pfizer address associated with product -> Distributor's address -> Retailer's address

A product would then be considered counterfeit if a seller is unable to produce the type of transaction described above.

One possible issue with this scheme is that it would still allow an hypothetical scammer to produce a valid transaction (assuming they previously bought the authentic product) and sell a fake product. However, there would be little economic incentive to do so given that their authentic product would now be valued as a fake (since they would have "lost" the ability to prove its authenticity).

Essentially, it would let a scammer buy an authentic product for the price of a fake. Not bad, but it doesn't scale well unless your goal is to acquire a bunch of authentic products for personal use with no intention of reselling. In other words, individual sellers (e.g. on Craigslist) might do it but it wouldn't be practical at a business level.

PS: I think I might just have described "colored coins" in a convoluted way.