I've been reading about identity theft recently, and I'm wondering about some possible solutions using the techniques of asymmetric/symmetric/hashing in encryption. My idea is going to cross those 3 subject areas, so bear with me as I try to explain my question.
I'm wondering whether it is/isn't viable to have something analogous to a public/private key infrastructure, such that the private key is the personal data that is being kept secret. This would also be analogous to symmetric crypto in that only the issuer (government/corporate) and the individual have the originals which are never actually used anywhere but are kept secret. Since the number only has to identify the individual (and is not sending some message that has to be decrypted) then it need only be verified by one of the 2 parties holding it. One could also add something analogous to a certification authority, although this would likely come down to implants of some sort which would be unpopular and I don't think they're necessary anyhow since the private info (SSN,DOB,etc) can be kept secret.
The goal is to minimize identity theft, although eradication would probably never happen. In this system, instead of writing down your DOB, SSN, credit card numbers, or whatever data is exclusive to some entity would instead be known only the 2 parties issuer and individual. Everyone else, when using that data, would get some public version of it, that can be replaced using another pin/password to encrypt it differently if it gets compromised. Some form of hash could also be used, since it needs only identify someone as authentic. So going to the grocery store or applying for college, someone would put down their hashed data and this could be verified within some national system as authentic, and used to identify the individual. This could be a vast improvement over the current system of simply using some number that is directly related to you such as SSN, DOB, or credit card number, and which can't (without serious difficulty and with poor propagation through the system) be changed.
Perhaps someone can point out the logical and/or logistical problems that would make this impractical.