Dec 16, 2015Lifesaving prescription drugs can cost $1,000 per pill, which makes them an extremely attractive target for counterfeiters. So are drugs such as Adderall (for treating attention deficit hyperactivity disorder), Cialis (for erectile dysfunction) and Tamiflu (for influenza). Researchers at Carnegie Mellon University may have a solution—a miniscule RFID transponder with an encrypted identifier that can be embedded in each pill.
The researchers began with the idea of creating transponders that were no bigger than the chip itself (the antenna would reside on the chip). A team member who is an expert in hardware security proposed adding encryption to ensure tag data could be communicated securely. The team then decided a useful application would be embedding transponders in pharmaceutical pills to address the multibillion-dollar problem of counterfeiting.
The big challenge with little transponders is getting power to the chip. A small antenna can't harvest much energy from the reader, but the researchers found a novel solution to the problem. "We are using specialized MEMS [microelectromechanical systems] post-processing to greatly improve the antenna efficiency," says L. Richard Carley, ST Microelectronics Professor in Carnegie Mellon's department of electrical and computer engineering. "In addition, we expect to operate at a frequency above 40 GHz to improve the antenna power transfer efficiency."
The pills would be authenticated before being swallowed. The transponder is encased in glass and is small enough to pass safely through the digestive tract. "We implemented security in much the same way as security for Web browsing is implemented—using the Advanced Encryption Standard," Carley says. "These medicines would not simply have a product code on the bottle—each pill would literally have a key and a complete AES engine built into the RFID tag, which is inserted into the pill."
The team is exploring simple schemes in which the RFID tag is powered up, the reader connects to a validating server, and the server provides a "challenge question." The tag uses its stored 128- or 256-bit key to generate an answer, and the server determines if that key was used in a pill made by that manufacturer. If so, the server would also provide information on the pill's fabrication date, lot number and so on.
"Since the challenge questions themselves would be randomly generated," Carley says, "a counterfeiter monitoring the communication between the tag and reader would not be able to create a device that would pass the authenticating server's test."
The researchers have received support from the university's Disruptive Health Technology Institute. They are developing a prototype chip with an antenna. "We expect to have test results from the prototype chips by next summer, if everything goes well," Carley says. If the results are good, pharmaceutical firms could be embedding the tags into their most expensive pills a few years after that.