Totally agree, a robust identity system could open up possibilities for a whole new set of experiments on Ethereum that currently aren’t feasible. A great quote from Glen Weyl about Blockchains is: “The problem is they formalized private property in an incredibly rich way, and yet they didn’t formalize democracy. And private property without democracy is an incredibly dark and scary thing.”
Unfortunately, there’s currently no well-functioning system to achieve identity (without a centralized issuer) on a blockchain that I know of. Some projects that are attempting to build identity systems are uPort, Democracy Earth, and some developing work by Glen Weyl.
uPort
From what I can tell, uPort doesn’t seem to be a “1 human, 1 identity” system, but I’m not an expert on their protocol. From this paper:
A user is free to create multiple uPortIDs that are unlinkable
The private key that controls a uPortID is stored only on the user’s mobile device.
Therefore, an important aspect of uPort relates to its social recovery protocol for the
event of loss or theft of the user’s mobile device. For that, users must nominate the
uPortIDs of trustees who can vote to replace the public key referenced in the controller
with one proposed by the user in need; once a quorum is reached between those trustees
on the new public key, the controller replaces the lost public key with the newly proposed public key. This process enables the user to maintain a persistent uPortID even
after the loss of cryptographic keys
Seems a lot more like an improved way of storing private keys than a formalized human identity.
Democracy Earth
Again, not an expert on their work, but Democracy Earth seems to be taking an approach where you prove your identity by sharing a video of yourself every year, and posting a hash of that video to a blockchain. They then layer on a reputation system to allow organizations to grant reputation to an individual. See their paper, especially pages 16-19.
Glen Weyl’s work
Glen has discussed on Twitter and at conferences a proposal for an identity system that he calls “Polypolitanism”. The basic idea is that our identity is the intersection (think Venn Diagram) of the different communities and our shared experiences/relationships with others. See some discussions on Twitter and this section from his talk at Devcon 4.