Personal identity seems like a generally intractable problem, despite the lofty goals stated in the introduction. And without it, the document is built on a fo

Personal identity seems like a generally intractable problem, despite the lofty goals stated in the introduction. And without it, the document is built on a foundation of sand. An argument that I find myself having quite frequently about Bitcoin and pseudonymity is that pseudonymity and concealing identity is not a feature of the system, but rather that defining two-way identity in any sort of useful way is such a difficult problem that solving it would be a bigger achievement than Bitcoin itself. Seeking a biological equivalent to a non-portable key in a TPM is pretty hopeless, and that's what you'd need to get a HUID -- not just a hash fingerprint that anyone can appropriate, but an internal signing mechanism to allow zero-knowledge verification of identity. And the inverse problem, the Sybil problem, is just as intractable, and as far as I know has never really been solved without a centralized issuing authority or reliance on a scarce resource (like proof-of-work, which even there solves only a weak variant of the Sybil problem by conflating the unit of "identity" with a unit of "work").