Technology News, WASHINGTON - Tiny radio-transmitter chips that make possible high-security car keys and swipe-by gasoline passes can be cracked using cheap technology, U.S. computer experts said on Saturday. The radio-frequency ID, or RFID, system uses a relatively simple code that criminals can easily decipher, making it easier to steal a car or get a free tankful of gasoline, the team at Johns Hopkins University in Baltimore and RSA Laboratories said.

"We've found that the security measures built into these devices are inadequate," said Avi Rubin, technical director of the Johns Hopkins Information Security Institute.

"Millions of tags that are currently in use by consumers have an encryption function that can be cracked without requiring direct contact. An attacker who cracks the secret key in an RFID tag can then bypass security measures and fool tag readers in cars or at gas stations," Rubin said in a statement.

Made by Texas Instruments (TXN.N: Quote, Profile, Research) , the RFID system studied for the report uses a device that prevents a car from starting unless both the right key and the correctly coded RFID chip are used.

"The devices have been credited with significant reductions in auto theft rates, as much as 90 percent," the researchers wrote. They cited Texas Instruments, which had been told about the problem, as saying the company had received no reports of thefts due to the vulnerability.

The fuel-purchase system uses a reader inside the gas pump that recognizes a key-chain tag waved nearby and automatically charges a designated credit card.

More than 150 million of the Texas Instruments transponders are embedded in keys for newer vehicles built by at least three leading makers, and in more than 6 million key-chain gas tags, the researchers said.

The problem is that the mathematical key used to code the verification system is too short, they said.