4 ms·

A simple SIM card or smart card is a suitable TPM for this, and can be obtained for pennies on the dollar.

• ytpete 9y ago
  The poster's point is that the link between that and the actual object of value is a huge weak point. Let's use expensive art as an example since it's such a commonly cited use case. Blockchain says I own an original Picasso painting. You pay me 1 BTC in exchange for me transferring ownership of the painting to you: blockchain says the painting is now yours, _and_ I have to ship you the physical painting so you can hang it in your house / art gallery / whatever rich people do with art. The problem is, how do you know I didn't ship you a fake replica and keep the original for myself, sell it to someone else on the sly, etc.? Sure, you could have a TPM which securely holds some data linking the physical smart card to the blockchain provenance record... but what links the physical smart card to the physical painting? Couldn't I just give you the fake painting + real smart card? You could get an art expert to authenticate the physical painting, of course -- but that's exactly the same reliance on a trusted third party that art collectors have today, and blockchain has done nothing to improve the situation...