From the whitepaper: "Kong notes do not use a secure element that allows for general programmability." Looks like they thought this through more than a typical

From the whitepaper: "Kong notes do not use a secure element that allows for general programmability." Looks like they thought this through more than a typical drive-by 'blockchain' project. With a limited secure circuit you'll be able to call functions that generate ECDSA key pairs on the card but without exposing an interface to retrieve the private key. Without this basic property you would have to fully trust that the issuer had not mass-extracted private keys (similar to how early privacy coins had a trusted setup phase.) Looks like they're also trying to structure this as 'reward cost for key extraction vs cost of mounting attacks' showing they have a plan in place for attacks. I'd argue the notes still have a tx cost though because the only way to know if a note has a valid private key is to challenge it with a unique, large, random number - which takes time and effort. Users of the notes will need an app for that and have to check every note against an on-chain 'smart contract' before accepting them? NFC might make some of that easier but there are still usability issues there.