This reminds me of how social security numbers weren't originally intended to be used as unique identification, but the demand for some form of identification was so strong that organisations ended up hackily using it anyway.[1]
This reminds me of how social security numbers weren't originally intended to be used as unique identification, but the demand for some form of identification was so strong that organisations ended up hackily using it anyway.[1]
In principle, all you need is a trusted arbitrator that's acceptable to all involved parties. This is how "multiple signatures" work on Bitcoin already; the third-party escrow can decide who's going to keep the coins by adding her signature to either party's claim.
It's scary to let internet companies have your actual DNA (though that didn't stop 23andme customers), so there could be an layer in between (a nonprofit? machine with a hardware security module?) that does the DNA sequencing and returns a digital signature to authenticate you.
The obvious downside is that it would work too well. Banning becomes much more serious of a thing when it's lifelong and potentially could affect your descendants. I hope I'm not giving anyone any ideas because this is horrible.