Brazil is heading in that direction. Every single corporation here and even freelance service workers are required by law to have a key/certificate pair to be

Brazil is heading in that direction. Every single corporation here and even freelance service workers are required by law to have a key/certificate pair to be able to do file taxes. Pretty much every single commercial transaction is signed with a certificate. It is not yet required for every individual citizen to have one, but everything points to that happening at some time in the future.