| > some out-of-band method > some external certification process Or just skip the extra complexity and have it all handled by a central authority? Yes, you can use a blockchain to implement it how you describe, but I still don't buy that it has any real advantages. Also, who would run the blockchain? > a whole bunch of DMVs could very well post to the same blockchain and only trust the validity of ID tokens issued by one another > with independent issuing authorities trusting one another If they are the only ones who can issue tokens and they have to trust each other anyway, why does it need to be a blockchain anyway instead of some shared database? Or if you want to keep it distributed, a peer-to-peer distributed hash table or other peer-to-peer database of ID tokens that only the DMV's have write access to. No need for a blockchain. > if you have a California driver's license and I (as a Nevadan) want to verify its validity If all the states share a blockchain, then they could just as easily share a database and web interface that you can look up. If they don't share a blockchain, then I don't see how its any different from each having their own system. I mean, even if its a blockchain, how well it works is then up to each state and if there's a centrally mandated blockchain they should be using, then there could also be a centrally mandated database they could be using. It just moves the goal posts around, it doen't in itself solve it. The person checking (bar staff in your example) still need a website or app that they can input the data to derive the hash (as not to leak personal data) and check the hash against the blockchain, this could just as easily work against a central or state database and how well it works, in either case, is still very much dependent on each state. It seems overly complicated to build this on or as a blockchain. |
Then every agency would have to trust some central authority. Maybe doable for interstate queries (with the associated federal bloat, but that's hardly anything new), but once you go international that becomes a lot harder.
> Also, who would run the blockchain?
Who runs Bitcoin? Ethereum? Cardano? Dogecoin?
> If they are the only ones who can issue tokens and they have to trust each other anyway, why does it need to be a blockchain anyway instead of some shared database?
The amount of trust required for "I'm reasonably sure this agency issued this driver's license" is far lower than the trust required for "I'm okay with this agency having control over my agency's records".
> Or if you want to keep it distributed, a peer-to-peer distributed hash table or other peer-to-peer database of ID tokens that only the DMV's have write access to.
A.k.a. a blockchain. You don't even need to restrict write access; DMVs can readily ignore transactions by non-DMV entities.
> If all the states share a blockchain, then they could just as easily share a database and web interface that you can look up.
That ain't anywhere near as easy, both politically and technically. This is already something they struggle do to, and distributed ledgers make that struggle entirely unnecessary.
> if there's a centrally mandated blockchain they should be using
There wouldn't need to be a mandate. States are perfectly capable of making agreements with one another, and could opt into a public blockchain at their leisure. CCW reciprocity is a good example of this; states have on their own come to recognize concealed carry permits issued by other states, and a blockchain would be a natural fit for recording and authenticating said permits under that dynamic.
Even assuming the need for a mandate, it's a hell of a lot easier for the federal government to say "hey, all states need to use this public blockchain per this standard" than for the federal government to roll out a whole central database that's scalable enough to handle queries nationwide and say "hey, all states need to use this central database".
> The person checking (bar staff in your example) still need a website or app that they can input the data to derive the hash (as not to leak personal data) and check the hash against the blockchain, this could just as easily work against a central or state database
Yes, and that would - again - require either:
1. a central authority that each state's agency trusts to be the record of truth, or:
2. 50 separate databases with 50 separate APIs.
A public blockchain absolves the need for either; agencies can maintain their licensing data autonomously (and, for that matter, data pertaining to those licenses; e.g. recording traffic citations, additional endorsements, etc., even for licenses issued by other agencies) without needing to deal with all that infrastructure.