Quote from: hoo2jalu on June 22, 2011, 05:19:47 AM

Not quite true. You just need some mechanism to convey amount out-of-band. Banks have been successful using amounts SMS'ed to a phone or robo-dialed to an automated voice system, for example. Not really a "secure display" and certainly not integrated into the point-of-sale unit / terminal. Yet still absolutely effective.

How do you do that through said hypothetical compromised/evil reader/payment device?

Edit: I guess you could sign the message, but then you have to rely on trusting the receiver of the message to be able to verify the signature - making SMS an unlikely candidate.