- Trust: I have to trust that the store creates the correct transaction (transaction on screen is the same as sent to the smart card for signing). I have not yet come up with a good answer here...
There are cards with display and press button where the amount could be confirmed direct on the card:
http://silicontrust.files.wordpress.com/2010/11/maia-display_custom_items-download_seealso_file.jpeg
http://www.incard.com/products.html