US team develops un-hackable RFID chip

According to MIT student Chiraag Juvekar the chip is designed to prevent so-called side-channel attacks which analyse patterns of memory access or fluctuations in power usage when a device is performing a cryptographic operation, in order to extract its cryptographic key.

"The idea in a side-channel attack is that a given execution of the cryptographic algorithm only leaks a slight amount of information," Juvekar said. "So you need to execute the cryptographic algorithm with the same secret many, many times to get enough leakage to extract a complete secret."

One way to thwart side-channel attacks is to use a random number generator to regularly change secret keys, but such a system would still be vulnerable to a "power glitch" attack, in which the RFID chip's power would be repeatedly cut right before it changed its secret key.

Power-glitch attacks have been used to circumvent limits on the number of incorrect password entries in password-protected devices, but RFID tags are particularly vulnerable to them, since they're charged by tag readers and have no onboard power supplies.