Sorry Blockchain — Math requires Axioms, the Internet requires Trust

I was listening to Oscar Santolalla’s excellent Let’s Talk About Digital Identity podcast the other morning — I believe this one, but won’t swear on it — and an interesting claim came up: that we could verify someone’s university graduation claim using the blockchain.

Why should we do that?

If you were to go to the (entirely hypothetical) URL https://claims.mun.ca/KOP4UI4YK4 and it told you I am a MUN graduate, and it was digitally signed by MUN, with a X.509 certificate chain that rooted at the Government of Canada, would this not be:

• the most straight forward thing you could do, from an existing web standards and protocols point of view,
• the highest level of trust you could reasonably achieve for a digital document.

Even if Newfoundland sank into the sea, having a copy of this digitally signed claim document would be sufficient to prove my graduate status (a more reasonable real world example is your university disappearing because of war and conflict).

What trust does the blockchain impart that a URL does not already? Anyone can claim they own the Mona Lisa on the blockchain; whether it is true or not depends on trust, and the blockchain adds nothing here.