Certificates, Reputation, and the Blockchain

This appears to be a re-creation of X509 and certificate transparency, but with a custom format in place of X509 and the block chain in place of CT.

The problem is that the existing infrastructure, though a little ugly in places, is very well thought out and has a vast ecosystem.

I can (and often do) simply plug in a USB stick that stores my private keys and then sign a PDF in such a way that the document is timestamped, signed, and bundled in such a way that clever tricks like swapping out an external font to change what a message says don't work.

The certificate has a verified identity in it, so I can accrue reputation under my own legal name if I want to, or I can create a self signed cert and use a pseudonym.

The CT logs are a blockchain-esque structure for logging of all created certificates, except searchable, and actually designed for certificates. It gives the same advantages as the blockchain does in this design, and then a whole lot more.

X509 is ugly, but still better than "append a signature after some lines of text", and it has the advantage of being widely supported with libraries in most major languages and frameworks. Usefully, web browsers know how to create a self signed cert and upload it to a server for signing, meaning the process of MIT issuing a university certificate can be easily automated.

Most of the problems of the existing PKI boil down to lack of UI polish. They aren't something you can fix just by throwing a block chain at it.

Discussing this with friends, we pondered the advantages of university degrees being cryptographically signed. If universities were created today, the idea that they would only use paper (or a scan) to certify a degree is laughable.

The process of verifying a degree is complicated - each university has a different system and the costs can be far from non-zero. This discourages employers from doing the checks.

The impact is far more than just "well we hired him/her and it didn't work out" - counterfeit degrees can be terrifying. Allen Ezell, a former FBI agent, notes that there are thousands of faked medical degrees[1]. Even in the case that the employee does a fine job, exposing a faked degree later can destroy their career from that point forward.

Yes, there are potential issues that go along with this idea (certificate revocation in the case of a compromised key, proper implementation of the system, etc) but even a flawed system would be far better than today given so very few degrees are certified by employers.

It should be as simply as attaching a link to your signed degree in your resume.

[1]: http://freakonomics.com/2012/07/30/freakonomics-goes-to-coll...

I think reputation should be the scarce resource for preventing sybil attacks, and not computing power via proof-of-work. The latter won't even work with new (and therefore small) blockchain networks, since a 51% attack is trivial. Reputation replaces distributed consensus with probabilistic value, relative to each participant. That's actually how currencies are discounted when being converted. Wildcat money during the free banking era was heavily discounted. Currencies and debts are accepted locally and from trusted people.

This seems to be like PGP keysigning web-of-trust, but instead of each participant managing their own copy you pile the whole thing onto the blockchain?

The tricky thing here is key management. What happens if you (or the university) lose a key or it's compromised?

I'm often annoyed by "blockchain" projects, but this is a very cool application of blockchain technology.

Does anyone know which blockchain the Media Lab is using? The actual Bitcoin one, or Namecoin, or some other one?