An NFT (Non-Fungible Token) is a data structure that points at a particular data object in a unique way. See it as a way of naming digital objects, such as photos, texts, audio or video, in a way that allows referring to them with no ambiguity.
The ability to refer to data objects allows to “mention” them in transactions. This seemingly trivial ability, when combined with the ability to create immutable records of transactions (as provided by Blockchains), allows us to create immutable records that refer to data objects.
Technically, NFTs do not require blockchains. You could take a photo of a cat, create an NFT for this photo, which is essentially a unique pointer to (or: a descriptor of) it, and then go on to write a real contract on paper that says “this photo of a cat, bearing this unique ID, is hereby assigned to John Smith”, whatever this assignment means.
Blockchains and smart contract technologies allow for such digital agreements to be stored in a public immutable record that does not allow anyone to change it once it was written. The combination of NFTs and blockchain-based smart contracts thus allows us to securely record agreements that declare ownership of digital goods. If you have any file (photo, text, video, etc.), you can create an attestation that tells the entire world that you assign this file to be owned by whoever. What does this “ownership” mean? – Good question; but whatever it means, billions of dollars have already been paid towards such ownerships. Is this real? The money surely is, but is also the value?
Continue reading "On the value of NFT"
Israel is probably the most advanced to date in terms of COVID19 vaccination. With more than one third of the residents fully inoculated, life can almost get back to pseudo-normal. This, however, requires being able to tell the vaccinated people apart from those who are not. The green pass, or vaccination certificate, is made to achieve precisely that. Technically, this government-issued certificate is not substantially different than a driver’s license, just that it’s shorter lived, can be stored in a phone app, and most importantly: was designed in a hurry.
For something that was launched so quickly, it seems to be decently architected, but slightly better work could still be done to protect that piece of attestation that is so critical to public health.
What do we require of a vaccination certificate? Not much, really. It obviously needs to be as secure as it could be made under the strict cost and distribution constraints. The certificate has to also be easily renewable (it currently expires every six months), and it has to be verifiable by a wide range of checkpoints with varying capabilities. Finally, verification has to be both reliable and fast; entry into a shopping mall cannot resemble passport control, and people cannot arbitrarily be locked out of key facilities just because of simple IT downtime.
The certificate itself is sent to its holder by e-mail (or via a web-site), to be printed at home. There are no measures that could be taken to prevent anyone with Microsoft Paint from crafting fake such certificates. The digital part of the vaccination certificate, i.e., the QR Code printed on it, is the only part of the certificate that can practically be used against forgery.
See the following write-up as a quick guide to cheap-but-secure attestation certificates; for COVID or otherwise.
Continue reading "COVID vaccination certificates done almost right"