The Dynamic Credit Card
The ubiquitous credit card is as secure as a box of Smarties in a kindergarten.
All credit cards should have a dynamic 4 last digits - 16 + 4 = 20 numbers.
The last four digits should change along a set sequence which is known only to the card and the card processor. This would change every 10 minutes.
When making a purchase whether online or at a vendor :
The card number and code would be validated via a secure web service which would authorise or reject it. Only the current generated or previous number would be accepted.
Each number would be valid for one purchase only.
The credit card could be equipped with a code or finger print recognition which would be needed to generate the number, so if the card was lost or stolen it would be unusable.
The card could also have a virtual version which could be installed on authorized cell phones.