One of TIs customers, Exxon Mobil Corp., uses the DST-40 tag in its Speedpass electronic payment system. "Weve been over all of this with Exxon, and they dont see any more risk [now] beyond the risk they were at already," Sabetti said."But what were saying is that if youre going to bother to build in encryption at all, you should do it correctly. You shouldnt use a proprietary encryption algorithm," Juels said. Other companies also make RFID tags for the same general markets. Why did the researchers focus only on TI? "Because TI is the most visible." Juels said. But TI wasnt being "picked on," he said. "Were also intending to look at a range of [other] RFID systems, [including both] active and passive RFID tags. Various [RFID systems] have various security and privacy weaknesses." Click here to read about RSAs RFID security services. For his part, Sabetti took issue with some of the cryptographic researchers methods and findings. The DST simulation system used in the attacks "took up the entire back seat of a car," he said. "[The researchers] were unable to produce an emulator which would be considered small or efficient." Sabetti also said that the RSA and Johns Hopkins researchers had demonstrated the attack for him, and that during the demo, they hadnt been able to intercept information outside of a two-foot range. "[Two feet] is a bit naïve," Juels said. "That is the nominal read range. Other systems, [with] a gate antenna, might achieve several feet for active scanning. Also, if an attacker waits until someone is [actually] using a Speedpass token, the potential passive eavesdropping range could be 10 feet." But Juels admitted that the researchers used only "crude" equipment in the attack against TIs 40-bit encryption. "Our attempt to do this was rather crude and uninformed, [and] cobbled together with some fairly inexpensive equipment. [But] once these systems have been widely deployed, there will be better equipment available. This was only a proof-of-concept [attack]," he said. Check out eWEEK.coms for the latest security news, reviews and analysis. And for insights on security coverage around the Web, take a look at eWEEK.com Security Center Editor Larry Seltzers Weblog.
Ari Juels, RSAs principal research scientist, agreed that customers have a right to try to "strike a balance" between speed, cost, and security.