In some ways, one company would be more difficult to audit than multiple companies, as the auditor wouldn't have any frame of reference. If we are looking at a

In some ways, one company would be more difficult to audit than multiple companies, as the auditor wouldn't have any frame of reference. If we are looking at a future with pervasive electronic voting machines from multiple manufacturers, I would insist on having multiple different kinds of machines in each polling place. That way, any meaningful differences between machines would stand out.