[cm2187]

But in a crypto-ledger system, if a computer in the UK embassy in Kenya is infected, you will still be issuing fake passports. This is effectively moving the problem away from a central server to all of the clients, and I am not sure this improves security.

I would assume that cryptographic signatures are a better protection against tempering.

[CyberDildonics]

It doesn't move the problem, it prevents it in certain scenarios or makes it more difficult. The scenario you describe is already a valid method of attack.