Why not just link link our identities to DNA, thumb prints, and other unique features of us? You want to withdraw money? Scan your eye here. You would like to apply for a driver's license? Spit into this jar. Someone will contact you in a week (or however long it takes to process DNA samples).
That way, the shadow can never really be separated from the person (or at least the difficulty increases). BTW, I recommend watching the movie Gattaca for an interesting take on identity theft of the future, when people are engineered and DNA is checked everywhere you go.