> This is why I think the really valuable and underserved use case of the blockchain is decentralized identity. You can prove you are who you say, you’ve studied where you claim, you’ve worked at the places on your resume, and do this in ways that cannot be subverted or lost. This would be invaluable for refugees who often struggle for months or years with proving they are who they are.
That's a very interesting use case, but it's hard for me to see exactly how this can be made to work.
Suppose you study at the National University of Unstabilia, which is located in a disaster-prone and conflict-riven environment. You complete your B.A. there, and you get the NUU to record this fact on a public blockchain.
A few years later, things are really bad in Unstabilia, so you move to Belgium. After you arrive there, you tell someone (maybe a prospective employer?) "hey, I'm Joeri, I'm a refugee from Unstabilia, and I have a B.A. degree!". For some reason this person is skeptical, so you say "it's OK, just look up the blockchain record with the following hash!".
Sure enough, the public blockchain contains an entry reflecting that someone named Joeri did, indeed, earn a B.A. at NUU a few years back. This is great, because maybe
* Unstabilia City was mostly destroyed in an earthquake, making it hard to contact people there, and many of the people who would have known you during your studies have likely died or become refugees themselves; and
* Lately, the new NUU administration really hates your ethnic group, so much so that it prefers to deny that people of your ethnicity were just recently widely represented among its student body; and
* Many of NUU's records were previously lost in a fire; and
* Before that, someone reputedly hacked NUU's computer systems and stole all of their records, and probably all of their cryptographic keys.
But thanks to the blockchain records, your new Belgian friends can still confirm that you actually studied at NUU, right?
But, how do they know that that record is really from NUU? How do they know that NUU really exists? How do they know what its signing keys were, and how long they remained under the university administration's control? How do they know whether it's a legitimate university? And, maybe most significantly, how do they know that you're the same Joeri who earned that degree back in the day, as opposed to some other Joeri? Are these records including some kind of digitally signed biometrics?