Date: Thu, Jun 2 1994 17:33:21 PDT From: Brock Meeks Subject: File 2--Jacking in from the SNAFU Port (Clipper Snafu update) ((Moderators' Note: The following article may not be reprinted or reproduced without the explicit consent of the author)). CyberWire Dispatch // Copyright (c) 1994 // Jacking in from the SNAFU Port: Washington, DC -- Matthew Blaze never intended to make the front page of the New York Times. He was just doing his job: Nose around inside the government's most secret, most revered encryption code to see if he could "break it." Blaze, a researcher for AT&T Bell Labs, was good at this particular job. Maybe a bit too good. Although he didn't actually "break" the code, he did bend the fuck out of it. That feat landed him a front page story in the June 2 issue of the New York Times. What Blaze found -- and quietly distributed among colleagues and federal agencies in a draft paper -- was that design bugs in Skipjack, the computer code that underlies the Clipper Chip encryption scheme, can be jacked around, and re-scrambled so that not even the Feds can crack it. This of course defeats the whole purpose of the Clipper Chip, which is to allow ONLY the government the ability to eavesdrop on Clipper encoded conversations, faxes, data transmissions, etc. What Blaze's research attacks is something called the LEAF, short for "Law Enforcement Access Field." The LEAF contains the secret access code needed by law enforcement agents to decode the scrambled messages. Blaze discovered that the LEAF uses only a 16- bit checksum, which is a kind of self-checking mathematical equation. When the checksum equations match up, the code is valid and everything's golden. The cops get to unscramble the conversations and another kiddie porn ring is brought to justice. (This is what the FBI will tell you... again and again and again and... ) But you can generate a valid 16-bit checksum in about 20 minutes, according to those crypto-rebels that traffic the Internet's Cypherpunks mailing list. "A 16-bit checksum is fucking joke," one cryptographic expert from the list told Dispatch. "If it weren't so laughable, I'd be insulted that all this tax payer money has gone into the R&D of something so flawed." But the New York Times got the story *wrong* or at least it gave only part of the story. "What the New York Times story didn't say was that the findings... had nothing to do with the Government standard, which covers voice, facsimile and low-speed data transmission," said an AT&T spokesman. AT&T was the first company to publicly support the Clipper Chip. A stance that was essentially bought and paid for by the U.S. government with the promise it would get big government contracts to sell Clipper equipped phones to Uncle Sam, according to documents previously obtained by Dispatch. The AT&T spokesman said the "frailty" that Blaze discovered doesn't actually exist in the Clipper Chip applications. "Our scientists, working with National Security Agency (NSA) scientists, were conducting research on proposed future extensions of the standard," he said. Those "future extensions" are the so-called Tessera chip, intended to be embedded in a PCMCIA credit card sized device that fits into a slot in your computer. When the NSA trotted out its Tessera card, it invited Blaze, among others, to review the technology, essentially becoming a beta-tester for the NSA. No formal contract was signed, no money changed hands. Blaze took on the job in a volunteer role. Using a prototype Tessera chip installed on a PCMCIA card, he broke the damn thing. AT&T claims the whole scenario is different from the Clipper because the LEAF generated by Clipper "is a real time application... with Tessera it's static," the spokesman said. He said Tessera would be used to encrypt stored communications or Email. "And with Tessera, the user has the ability to get at the LEAF," he said, "with Clipper, you don't." Blaze will deliver his paper, titled "Protocol Failure in the Escrowed Encryption Standard," this fall during the Fairfax Conference. His findings "should be helpful" to the government "as it explores future applications," of its new encryption technology the AT&T spokesman said. In our view, it's better to learn a technology's limitations while there's time to make revisions before the Government spends large sums to fund development programs." This is an important, if subtle statement. The Clipper Chip never underwent this type of "beta-testing," a fact that's drawn the ire of groups such as Computer Professionals for Social Responsibility (CPSR) and the Electronic Frontier Foundation (EFF). When the White House began to take hits over this ugly situation, it agreed to have an independent panel of experts review the classified code to check for any trapdoors. Those experts claim they found nothing fishy, but their report -- alas --has also been classified, leading to further demands for openness and accountability. The White House is stalling, naturally. But in an apparent about face, the NSA allowed an "open" beta- testing for Tess and -- surprise -- we find out there are bugs in the design. Okay, Pop Quiz time: Does the existence of "Blaze Bug" make you feel: (A) More secure about the government's claim that Clipper will only be used to catch criminals and not spy on the citizenry. (B) Less secure about everything you've ever been told about privacy and encryption by the Clinton Administration. (C) Like this entire episode is really an extended "Stupid Pet Tricks" gag being pulled by David Letterman. If you're still unsure about Clipper, check this quote from the AT&T spokesman: "It's worth noting that Clipper Chip wasn't subjected to this type of testing." Ah-huh... any questions? The NSA is trying to downplay the news. "Anyone interested in circumventing law enforcement access would most likely choose simpler alternatives," said Michael Smith, the agency's planning director, as quoted by the New York Times. "More difficult and time-consuming efforts, like those discussed in the Blaze paper, are very unlikely to be employed." He's right. Those "simpler alternatives" include everything from private encryption methods to not using a Clipper equipped phone or fax in the first place. (Of course, the FBI keeps insisting that criminals won't use any of this "simpler" knowledge because they are "dumb.") Despite the NSA's attempt to blow off these findings, the agency is grinding its gears. One NSA source told Dispatch that the Blaze paper is "a major embarrassment for the program." But the situation is "containable" he said. "There will be a fix." Dispatch asked if there would be a similar review of the Clipper protocols to see if it could be jacked around like Tess. "No comment," was all he said. Meeks out... ------------------------------ Date: Thu, Jun 2 1994 17:33:21 PDT From: Brock Meeks Subject: File 3--Jacking in from the "We Knew It All Along" Port (Clipper) ((Moderators' Note: The following article may not be reprinted or reproduced without the explicit consent of the author)). CyberWire Dispatch // Copyright (c) 1994 // Jacking in from the "We Knew It All Along" Port: Washington, DC -- The key technology underlying the Administration's Tessera "Crypto Card" was fatally flawed from its inception, Dispatch has learned. Government researchers working for the National Security Agency have known for months about the flaw, but purposefully withheld that information from the public, a government official acknowledged today to Dispatch. Cryptographic researchers at the super-secret NSA have known all along that the program used to scramble a key part of the government's Clipper system could be thwarted by a computer savvy user with 28 minutes of free time, according to an NSA cryptographic expert that spoke to Dispatch under the condition he not be identified. "Everyone here knew that the LEAF (Law Enforcement Access Field) could be fucked with if someone knew what they were doing," the NSA expert said. "We knew about the flaw well before it became public knowledge. What we didn't know is how long it would take an outside source to discover the flaw." In essence, the NSA decided to play a kind of high-tech cat and mouse game with a technology being hailed as the most secure in the world. So secure, the White House is asking the public to give up a degree of privacy because there's no chance it can be abused. "We figured [the presense of the flaw] was an acceptable risk," the NSA expert said. "If no one found out, we probably would have fixed it sooner or later," he said. "I can't imagine that we would have let that one slip through." But someone spoiled the end game. A 33-year-old AT&T scientist Matthew Blaze discovered the crack in the White House's increasingly crumbling spy vs. citizen technology. Acting as a kind of beta-tester, Blaze found several techniques that could be used to successfully thwart the LEAF, the encrypted data stream needed by law enforcement officers in order to identify what amounts to a social security number for each Clipper or Tessera chip. Once the LEAF is in hand, law enforcement agents then submit it to the "key escrow agents." These escrow agents are two government authorized agencies that keep watch over all the keys needed to descramble Clipper or Tessera encoded conversations, faxes or data transmissions. Without the keys from these two agencies, the law enforcement agents hear nothing but static. Without the LEAF, the agencies won't cough up the keys. Bottom line: If the LEAF is fucked, so is access to the scrambled communications. What Blaze so eloquently discovered is that someone with a modicum of knowledge could do was jack around with the LEAF, rendering it unusable. What Blaze didn't realize is that he was merely acting as an NSA stooge. But the methods discovered by Blaze, and outlined in a draft paper he'll later present this month during a high brow security shindig known as the Fairfax conference, are cumbersome. "The techniques used to implement (the work arounds) carry enough of a performance penalty, however, to limit their usefulness in real-time voice telephony, which is perhaps the government's richest source of wiretap-based intelligence," Blaze writes in his paper. Notice he says "limit" not "completely render useless." Important distinction. Are there other, faster, more clever ways to circumvent the LEAF? "If there are, I wouldn't tell you," the NSA crypto expert said. Shut Up and Chill Out ===================== The National Institute of Standards and Technology (NIST), the agency walking point for the White House on the Clipper issue, takes these revelations all in stride. Sort of a "shut up and chill out" attitude. The techniques described by Blaze "are very unlikely to be used in actual communications," a NIST spokeswoman said. Does that mean they could never be used? "It's very unlikely." NIST, when confronted with the fact that NSA researchers knew all along that the technology was broken, was unapologetic. "All sound cryptographic designs and products consider tradeoffs of one sort or another when design complexities, costs, time and risks are assessed," the NIST spokeswoman said. The Clipper family of encryption technologies "is no exception," she said. NIST said that the Tessera card "isn't a standard yet, so the process of testing it's integrity is ongoing." The technology in Tess is known as the Capstone chip, which, unlike the Clipper Chip, hasn't yet been accepted as a standard, NIST said. Flaws, therefore, are assumably just part of an ongoing game. The fact that the NSA knew about this flaw when it asked people like Blaze to test it was "just part of the ongoing testing procedure," the spokeswoman said. And if Blaze or some other idea hamster hadn't discovered the flaw? You make the call. What about Clipper? Are there such flaws in it? NIST says "no" because it has already been through "independent testing" and accepted as a standard. If there are flaws there, they stay put, or so it seems. Clipper's My Baby ================= Beyond the high risk crypto games the NSA has decided to play, there's another disturbing circumstance that could torpedo the Clipper before it's given its full sailing orders. This obstacle comes in the form of a patent dispute. Silvio Micali, a scientist at the massachusetts Institute of Technology says the Clipper is his baby. He claims to hold two crucial patents that make the Clipper tick. "We are currently in discussions with Mr. Micali," NIST said. "We are aware of his patent claims and we're in the process of addressing those concerns now," a NIST spokeswoman said. She wouldn't go into details about as to the extent of the talks, but obviously, the government is worried. They haven't flatly denied Micali's claims. If this all sounds like a bad nightmare, you're right. NIST ran into the same problems with its Digital Signature Standard, the technology they've adopted as a means to "sign" and verify the validly of electronic mail messages. Others jumped on the government's DSS standard, claiming they were owed royalties because they held patents on the technology. These discussions are still "ongoing" despite the government's adoption of the standard. The same situation is now happening with Clipper. One could make a case that Yogi Berra is the policy wonk for the Clipper program: "It's like deja vu all over again," Berra once said. So it is, Yogi... so it is. Meeks out...