A Microsoft researcher has suggested tattooing passwords on patients with pacemakers and other implanted medical devices to ensure the remotely-controlled gadgets can be accessed during emergencies.
The proposal, by Stuart Schechter of Microsoft Research, is the latest to grapple with the security of implanted medical devices equipped with radio transmitters they can be controlled without the need for surgery. Besides pacemakers, other types of potentially vulnerable devices include insulin pumps and cardiac defibrillators.
In 2008, researchers demonstrated that heart monitors were susceptible to wireless hacks that caused pacemakers to shut off or leak personal information. But equally devastating are scenarios in which physicians are unable to provide emergency care because they don't have the access codes needed to control the devices.
In a paper published last week, Schechter proposed that access to such devices be controlled with encryption similar to what's used on wi-fi networks. Access keys would then be tattooed on patients using ink that's invisible under most conditions.
"We propose that a user-selected human-readable key be encoded directly onto patients using ultraviolet-ink micropigmentation, adjacent to the point of implantation," he wrote. "To increase reliability the encoding could be augmented to include an error correcting code and/or be replicated in full on the base of the patient's leftmost foot - at the arch."
Equipment used to remotely communicate with the implanted devices would be equipped with an ultraviolet light and a keypad or touchscreen for transmitting the code.
Schechter said patients can't be counted on to provide the code because they may forget it or lose consciousness during an emergency. Bracelets, meanwhile, may reveal the patient's condition to strangers or potential attackers. Passwords transmitted by RFID, or radio frequency identification, technology, are susceptible to snooping, he said.
The proposal comes five months after boffins from Switzerland suggested using ultrasound waves as a way to prevent attacks on radio-controlled pacemakers.
A PDF of Schechter's paper is here. ®