A presentation on the security shortcoming of RFID technologies was pulled at the last minute from a Black Hat conference this week.

Security researcher Chris Paget of IOActive intended to demonstrate how building access controls based on RFID technology might be circumvented at the conference in Washington this week.

But the manufacturer of the cards, HID Corp, said the hacking tools due to feature during the presentation violated its patents. In a statement, IOActive said it withdrew the presentation on legal advice.

IOActive argues that the concepts behind its research are not new and that its work simply illustrates potential security shortcomings of contactless building access controls that HID has also noted in the past.

Filling the hole left by IOActive's withdrawal, an ACLU laywer will discuss the issues raised by the affair.

Black Hat, often the venue of edgy presentations, is no stranger to controversies like this. The IOActive contretemps recalls the furore over a presentation by Michael Lynnon, highlighting security weaknesses in devices running's Cisco IOS software at Black Hat, Las Vegas in 2005. ®