[This was on the Defcon list...apologies if it's already been posted today.] Zach Babayco zachb@netcom.com <-------finger for PGP public key http://www.geocities.com/SiliconValley/Park/4127 ----- If you need to know how to set up a mail filter or defend against emailbombs, send me a message with the words "get helpfile" (without the " marks) in the SUBJECT: header, *NOT THE BODY OF THE MESSAGE!* I have several useful FAQs and documents available. ---------- Forwarded message ---------- Date: Tue, 19 Nov 1996 21:17:49 +0000 From: Simon Gardner <simon@access.org.uk> To: aaa-list@access.org.uk Cc: dc-stuff@dis.org Subject: Cracks Are Found In Smartcard Security Cracks Are Found In Smartcard Security Researchers have found a way to attack tough codes, says Michael McCormack. A team of Cambridge and German researchers have used ordinary hacking methods and £150 worth of electronics equipment to crack the "world's most secure computer chip", used in automated teller machines worldwide. They say their technique could be used to reprogram a wide variety of supposedly secure smartcard applications, including the Mondex "money on a card" bankcard, GSM phones, and satellite TV descramblers. Dr Ross Anderson, of Cambridge University Computer Laboratory, working with German researcher Markus Kuhn, used methods pioneered by Sky-TV hackers to crack the Dallas chip, described by the manufacturer as having "the most sophisticated security features available in any microcontroller" and used in most of Britain's cash machines. The chip decodes the information read from bankcards and authorises the bank machine to process transactions ordered by the owner. It is also used by the Mondex system to verify the amount of electronic money available to the cardholder. Anderson and Kuhn used cheap and easily built electronic equipment to send wrong instructions to the chip, observing how it encrypted bad data. By sending such errors through all parts of the encryption system, they could work out its key. "You will have to have backup security" "Once you know that, you can instruct it to put some zeros on the end of your Mondex balance, start unscrambling your satellite feed, anything you like," Anderson said. "Breaking the average smartcard can be done by anyone with a modicum of technical knowledge by the methods we have described. The expense is negligible but it is time-consuming." Their discovery could spell the end of the Mondex system, which relies entirely on the security of the smartcards for its integrity. "I don't think you will be able to have floating systems like Mondex any more, where all the information is held on the smartcards," said Anderson. "You will have to have backup security with authorisation calls and auditing, just like ordinary credit cards. The smartcards are no longer reliable on their own." John Beric, head of security at Mondex, said security was a moving target, and he was unconcerned by the findings. "I welcome Dr Anderson's work, because it's a benchmark that establishes the difficulty of breaking the system," he said. "I take some comfort that it's taken a Cambridge academic and a very bright student to do this." Beric said Mondex had a scheme for continually improving its security by transparently introducing new smartcard chips every two years. "It's not static, we're ahead of the criminal now, and we believe the technology is there to ensure that we stay ahead." Anderson said his latest research indicated that two of the world's most widely used systems for encoding sensitive financial information - the RSA and DES encryption standards used by most banks - could also be cracked easily." [The London Telegraph, 19th November 1996]