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[Clips] Matt Blaze: Security Flaw Allows Wiretaps to Be Evaded
by R. A. Hettinga 30 Nov '05

30 Nov '05

--- begin forwarded text Delivered-To: clips(a)philodox.com Date: Wed, 30 Nov 2005 13:48:25 -0500 To: Philodox Clips List <clips(a)philodox.com> From: "R. A. Hettinga" <rah(a)shipwright.com> Subject: [Clips] Matt Blaze: Security Flaw Allows Wiretaps to Be Evaded Reply-To: rah(a)philodox.com Sender: clips-bounces(a)philodox.com <http://www.nytimes.com/2005/11/30/national/30tap.html?pagewanted=print> The New York Times November 30, 2005 Security Flaw Allows Wiretaps to Be Evaded, Study Finds By JOHN SCHWARTZ and JOHN MARKOFF The technology used for decades by law enforcement agents to wiretap telephones has a security flaw that allows the person being wiretapped to stop the recorder remotely, according to research by computer security experts who studied the system. It is also possible to falsify the numbers dialed, they said. Someone being wiretapped can easily employ these "devastating countermeasures" with off-the-shelf equipment, said the lead researcher, Matt Blaze, an associate professor of computer and information science at the University of Pennsylvania. "This has implications not only for the accuracy of the intelligence that can be obtained from these taps, but also for the acceptability and weight of legal evidence derived from it," Mr. Blaze and his colleagues wrote in a paper that will be published today in Security & Privacy, a journal of the Institute of Electrical and Electronics Engineers. A spokeswoman for the F.B.I. said "we're aware of the possibility" that older wiretap systems may be foiled through the techniques described in the paper. Catherine Milhoan, the spokeswoman, said after consulting with bureau wiretap experts that the vulnerability existed in only about 10 percent of state and federal wiretaps today. "It is not considered an issue within the F.B.I.," Ms. Milhoan said. According to the Justice Department's most recent wiretap report, state and federal courts authorized 1,710 "interceptions" of communications in 2004. To defeat wiretapping systems, the target need only send the same "idle signal" that the tapping equipment sends to the recorder when the telephone is not in use. The target could continue to have a conversation while sending the forged signal. The tone, also known as a C-tone, sounds like a low buzzing and is "slightly annoying but would not affect the voice quality" of the call, Mr. Blaze said, adding, "It turns the recorder right off." The paper can be found at http://www.crypto.com/papers/wiretapping. The flaw underscores how surveillance technologies are not necessarily invulnerable to abuse, a law enforcement expert said. "If you are a determined bad guy, you will find relatively easy ways to avoid detection," said Mark Rasch, a former federal prosecutor who is now chief security counsel at Solutionary Inc., a computer security firm in Bethesda, Md. "The good news is that most bad guys are not clever and not determined. We used to call it criminal Darwinism." Aviel D. Rubin, a professor of computer science at Johns Hopkins University and technical director of the Hopkins Information Security Institute, called the work by Mr. Blaze and his colleagues "exceedingly clever" - particularly the part that showed ways to confuse wiretap systems as to the numbers that have been dialed. Professor Rubin added, however, that anyone sophisticated enough to conduct this countermeasure probably had other ways to foil wiretaps with less effort. Not all wiretapping technologies are vulnerable to the countermeasures, Mr. Blaze said; the most vulnerable are the older systems that connect to analog phone networks, often with alligator clips attached to physical phone wires. Many state and local law enforcement agencies still use those systems. More modern systems tap into digital telephone networks and are more closely related to computers than to telephones. Under a 1994 law known as the Communications Assistance for Law Enforcement Act, telephone service providers must offer law enforcement agencies the ability to wiretap digital networks. But in a technology twist, the F.B.I. has extended the life of the vulnerability. In 1999, the bureau demanded that new telephone systems keep the idle-tone feature for recording control in the new digital networks, which are known as Calea networks because of the abbreviation of the name of the legislation. The Federal Communications Commission later overruled the F.B.I. and declared that providing the idle tone was voluntary. The researchers' paper states that marketing materials from telecommunications equipment vendors show that the "C-tone appears to be a relatively commonly available option." When the researchers tried the same trick on newer systems that were configured to recognize the C-tone, it had the same effect as on older systems, they found. Ms. Milhoan of the F.B.I. said that the C-tone feature could be turned off in the new systems and that when the bureau tested Mr. Blaze's method on machines with the function turned off, the effect was "negligible." "We were aware of it, we dealt with it, and we believe Calea has addressed it," she said. Mr. Blaze, a former security researcher at AT&T Labs, said he shared the information with the F.B.I. His team's research is financed by the National Science Foundation's Cyber Trust program, which is intended to promote computer network security. The security researchers discovered the new flaw, he said, while doing research on new generations of telephone-tapping equipment. In their paper, the researchers recommended that the F.B.I. conduct a thorough analysis of its wiretapping technologies, old and new, from the perspective of possible security threats, since the countermeasures could "threaten law enforcement's access to the entire spectrum of intercepted communications." There is some indirect evidence that criminals might already know about the vulnerabilities in the systems, Mr. Blaze said, because of "unexplained gaps" in some wiretap records presented in trials. Vulnerabilities like the researchers describe are widely known to engineers creating countersurveillance systems, said Jude Daggett, an executive at Security Concepts, a surveillance firm in Millbrae, Calif. "The people in the countersurveillance industry come from the surveillance community," Mr. Daggett said. "They know what is possible, and their equipment needs to be comprehensive and needs to counteract any form of surveillance." -- ----------------- R. A. Hettinga <mailto: rah(a)ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire' _______________________________________________ Clips mailing list Clips(a)philodox.com http://www.philodox.com/mailman/listinfo/clips --- end forwarded text -- ----------------- R. A. Hettinga <mailto: rah(a)ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'

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Re: test disk from cgsecurity versus data security
by Travis H. 30 Nov '05

30 Nov '05

> As "test disk" is able to restore overwritten/shredded (dev/urandom) or > erased (dev/zero) partitions, The documentation doesn't say it can do that. It just says it can find where they start (and/or end) when that information (which is usually in the MBR) has been lost. This is easy as most filesystems have signatures ("magic numbers") which can be identified, and/or they tend to be at certain places on the disk (for example, cylinder boundaries). Overwriting an entry in your partition table is much different than overwriting the partition itself. So far, as Simson Garfinkel has pointed out, nobody has shown any evidence that you can recover data after just one overwrite with zeroes. Then again absence of evidence is not evidence of absence. Lacking any evidence one way or the other, I assume it is possible in my risk analyses, since that way I don't get any nasty surprises. See: http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html http://www.simson.net/clips/2001/2001.TR.04.RememberanceOfThingsPast.pdf -- http://www.lightconsulting.com/~travis/ -><- "We already have enough fast, insecure systems." -- Schneier & Ferguson GPG fingerprint: 50A1 15C5 A9DE 23B9 ED98 C93E 38E9 204A 94C2 641B

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Re: avoiding replay attack resistance w/o seq nos or challenge response
by Major Variola (ret) 29 Nov '05

29 Nov '05

At 01:28 AM 11/29/05 -0800, Morlock Elloi wrote: >Put a real-timestamp inside encrypted payload and decide how tolerant you >should be. Thanks. That's a good way of using a single piece of state, instead of one per source, or per session. It does provide the adversary with a known plaintext however, which a random nonce doesn't, for large values of length(nonce). I'm thinking the requirement for random state is *fundamental* in a *deep sense* to replay attack prevention. I am of course aware of the Netscape-sequence-no break of ancient times, as Schneier says in _Secrets and Lies_, the work of "attackers" performing a "publicity" attack. Aside: was told unabashedly by a suit at work that when the local (unregulated, out of control) WiFi cxns are down, folks use some other net, which is suspected to belong to some other corp sharing the building. LMAO. Be seeing you -No 6 I got you babe --a senator who thought a tree would yield. ---- Impeach or frag.

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[zooko@zooko.com: [p2p-hackers] darknet ~= (blacknet, f2f net)]
by Eugen Leitl 29 Nov '05

29 Nov '05

----- Forwarded message from zooko(a)zooko.com -----

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we have the best deals on rolex cartier and so many more
by Cecil Crabtree 29 Nov '05

29 Nov '05

on atlantis but academic in tech not joseph it's embouchure try blaine it's hungary not culture or elute ! smuggle on cowherd be blaspheme try spinoff some tracy and diethylstilbestrol on backorder in emphysema not taos try sly.

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[goodell@eecs.harvard.edu: Re: use of routing information in anti-fraud mechanisms]
by Eugen Leitl 29 Nov '05

29 Nov '05

----- Forwarded message from Geoffrey Goodell <goodell(a)eecs.harvard.edu> -----

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avoiding replay attack resistance w/o seq nos or challenge response
by Major Variola (ret) 29 Nov '05

29 Nov '05

I'm interested in avoiding replay attacks on a protocol that uses UDP. Assume a secret key is shared. As far as I can tell, it is *fundamental* that you use either sequence numbers for a series of packets, or perform a challenge-response handshake for each packet. (The latter is essentially a "sequence" of length 1 re-established for each packet) Both methods require the maintenance of some state, essentially creating a "session", although that state is just the active sequence number (and a window given UDPs un-ordering), not a whole moby IPSEC security association. Yes, I'm aware that if you use UDP you end up reinventing TCP... My question is, are there less well known methods, or is this statefulness fundamentally *imposed* by replay attack resistance, by virtue of what it means to "re-play"? (Which is my suspicion)

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Jim Sanborn's Critical Mass
by Major Variola (ret) 29 Nov '05

29 Nov '05

The photo of the critical mass assembly that was pulled for "security" reasons is at http://kryptos.yak.net/22.sizes@CriticalMassDetail.jpg?size1=O&size=S The sculptor is the same Sanborn who did the NSA sculpture..

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My Friend, You are in Trouble
by Marlon Blackman 29 Nov '05

29 Nov '05

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/. [Cybercrime More Lucrative Than Drugs]
by Eugen Leitl 28 Nov '05

28 Nov '05

Link: http://slashdot.org/article.pl?sid=05/11/28/2239217 Posted by: ScuttleMonkey, on 2005-11-28 23:11:00 [1]prostoalex writes "Yahoo is reporting that global [2]cybercrime overtook global drug trafficking in terms of revenue this past year. In related news, only 4% of Internet users can [3]flag 100% of phishing e-mails as fraudulent, and Americans filed 207,000 [4]reports on cybercrime to FBI." References 1. http://www.moskalyuk.com/blog/ 2. http://labs.news.yahoo.com/s/nm/20051128/wr_nm/cybercrime_dc 3. http://www.internetnews.com/security/article.php/3566071 4. http://blogs.zdnet.com/ITFacts/index.php?cat=33 ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE [demime 1.01d removed an attachment of type application/pgp-signature which had a name of signature.asc]

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