That I don’t know the answer too. And i would like more information about how it works. I am mostly familiar with Crypto in block chains work and I still wouldn’t say i fully understand that either.
I am also a little confused when they say unchanging. Sure block chain are unchanging but I am assuming you can add new data that would take priority of old data. I don’t think you would want a system that you could never change your key once you add it. Because that is stupid keys can and will get compromised eventually.
Blockchains are an immutable ledger, meaning any data initially entered onto them can’t be altered. Yen realized that putting users’ public keys on a blockchain would create a record ensuring those keys actually belonged to them – and would be cross-referenced whenever other users send emails. “In order for the verification to be trusted, it needs to be public, and it needs to be unchanging,” Yen said.
Personally I consider a tape only a valid solution in the 100+TB range. (At least cost wise) Unless you happen to have a tape drive already at your disposal…
Because Privacy isn’t 1 or 0 situation. It is granular thing you may think using YouTube crosses the line but others might not agree.
We as a community can choose what crosses the line for this community.
Personally I am fine with YouTube links, there is usually a bot posting a more private link down below if you want. It makes it easy to pick one of the other it isn’t that big of a deal.