One of the key problems is in verifying citizenship. None of the existing identities work well for this. I remember when India introduced Aadhar card, it was

One of the key problems is in verifying citizenship. None of the existing identities work well for this. I remember when India introduced Aadhar card, it was explicitly mentioned that it is not a proof of citizenship and there was a "challenge" to come up with a good identity proof for citizenship.