Contactless payments and the security challenges

This is a good summary of what is going on with NFC tokens and payments and a brief discussion of the security implications.

Contactless payments and the security challenges: "Please note that this is an example given for the purpose of discussion; it is not meant to represent any of the operational schemes discussed in this article. The security of this typical example scheme is not absolute. There is no cardholder verification (i.e. a signature or a PIN), but all transactions are authorised online, so a lost or stolen card can be blocked as soon as it is reported (although it has to be said that consumers will generally notice the loss or their keys or mobile phone pretty quickly). For this example scheme, it might be useful to add an online PIN only for transactions above �20 or so."