[bga]

or a digital signature, or a MAC. Something where we could verify against a publicly-known value safely, and without giving that secret part away to anyone else. The secret would be between the Federal Government and the citizen.

[Simon_says]

Why should the government have it at all? Just let private citizens manage their own private key.

[nindalf]

And what happens when people inevitably lose their private key? How will they regain access to their SSN?

[u801e]

They would probably have to through a similar procedure as they do to get a replacement social security card. That is, they would have to present at least a drivers license and US passport at one of the local social security administration offices.

At that point, they can regenerate the key-pair and have the SSA official sign the public key and keep that on file.

Now, presumably, it is possible to forge both documents, but I would think that the government could check their records (federal and state) to verify the authenticity of the provided documentation.

[bga]

Exactly. You can't have perfect trust in every citizen to keep track of these things. And if it's a government issued ID in the first place, I see no trouble with them having your private key as well. Just don't reuse that key.

This would take a lot of solid investment politically, and technically, to make it even slightly feasible to work for the average Joe.