Subject: RISKS DIGEST 16.17 REPLY-TO: risks@csl.sri.com RISKS-LIST: RISKS-FORUM Digest Friday 17 June 1994 Volume 16 : Issue 17 FORUM ON RISKS TO THE PUBLIC IN COMPUTERS AND RELATED SYSTEMS ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator ***** SORRY FOR ABORTIVE ATTEMPT AT MIME-ING RISKS in RISKS-16.15. ***** I MAY TRY AGAIN SOME DAY IF I GET THE RIGHT FORMAT! ***** See last item for information on RISKS (comp.risks) ***** Contents: Poulsen guilty of L.A. charges (Mich Kabay) Counterfeit graduation tickets (Mich Kabay) "Virtual Billboard" on TV (R. Peter Jackson) Misdirected Mail (Jeffrey Austen) Revenue Canada database allows birthday change (John Howard) NIST Response to Blaze Attack on Clipper (Ed Roback) ROLM phones and "Do Not Disturb": how to lose calls (Rob Levandowski) A320 hull losses: Lies, damned lies and statistics (Pete Mellor) Info on RISKS (comp.risks), contributions, subscriptions, FTP, etc. ---------------------------------------------------------------------- Date: 16 Jun 94 18:01:35 EDT From: "Mich Kabay [NCSA Sys_Op]" <75300.3232@CompuServe.COM> Subject: Poulsen guilty of L.A. charges >From the United Press International newswire (94.06.14 @ 18:45 EDST) via Executive News Service (GO ENS) on CompuServe: "Hacker Pleads Guilty to Fraud", By ELKA WORNER LOS ANGELES, June 14 (UPI) -- A computer hacker accused of breaking into computer systems to rig promotional contests at radio stations, eavesdrop on private citizens and thwart police investigations, pleaded guilty Tuesday to fraud. Kevin Poulsen, 28, of Menlo Park, faces 40 years in prison and a $1,750,000 fine when he is sentenced Oct. 17. He pleaded guilty in federal court to computer fraud, interception of wire communications, mail fraud, money laundering and obstruction of justice. The author summarizes the case against Poulsen [I added details she didn't include]: o [manipulated the phone systems to cheat in radio-station call-in contests that awarded prizes to a specific caller in sequence]; he stole "two Porsches from radio station KIIS-FM, $20,000 in cash from KPWR-FM and at least two trips to Hawaii and $2,000 in cash from the same station." o used lies and counterfeit IDs to claim and then sell his prizes. o uncovered FBI-run businesses, spotted FBI wiretaps and listened in on conversations of ordinary citizens. o called a confederate "minutes after his arrest to ... hide the computers used in his illicit activities." o lived on the run for 18 months after being indicted in San Francisco by a grand jury until his arrest in April 1991 . o in July 1994, he will be tried "on 18 counts of telecommunications and computer related fraud, including charges that he stole Pacific Bell access codes to invade an Army computer network and to obtain information used in FBI investigation of former Philippine President Ferdinand Marcos." o worked for the Soviet consul in S.F. by obtaining unpublished telephone numbers." Michel E. Kabay, Ph.D. / Dir Education / Natl Computer Security Assn ------------------------------ Date: 16 Jun 94 18:01:29 EDT From: "Mich Kabay [NCSA Sys_Op]" <75300.3232@CompuServe.COM> Subject: Counterfeit graduation tickets >From the Reuter newswire (94.06.14 @ 14:25 EDST) via Executive News Service (GO ENS) on CompuServe: DARTMOUTH ALUMNUS CAUGHT SELLING PHONY GRADUATION TICKETS HANOVER, N.H., June 14 (Reuter) - A former Dartmouth College student was arrested for selling counterfeit graduation tickets for the event at his Ivy League alma mater, police said Tuesday. Corby Edward Page, 23, a computer programmer from Houston, Texas and a 1992 Dartmouth graduate, admitted to making the fake tickets on his computer and selling them before the June 12 graduation for $15 each, said Hanover Police Sergeant Christopher O'Connor." According to the story, a student who bought a bogus ticket "called police after noticing the fake tickets were different from the real ones." The idiot grad was caught "in the lobby of the posh Hanover Inn, opposite the Dartmouth campus, as he sold tickets, police said." He was charged with fraud. ------------------------------ Date: Thu, 16 Jun 1994 23:07:10 -0700 (PDT) From: "R. Peter Jackson" Subject: "Virtual Billboard" on TV On Wednesday, June 15, 1994, the Los Angeles Times reported on page D7 in their relatively new weekly section called "The Cutting Edge Computing/Technology/Innovation" the following: "Virtual Billboard" Is Sign of the Times Baseball teams would love the revenue from behind-the-batter billboards, and advertisers like the idea of being on screen without fear of remote-control zapping. But purists denounce the idea as antithetical to the tradition of the game, and some players say the signs make it harder to see the ball. Now inventors have devised a system that will create electronic billboards visible only to people watching on TV. Princeton Electronic Billboards Inc. in Princeton, N.J., has been testing "virtual billboards" with the Baltimore Orioles and its telecasters. Working with the David Sarnoff Research Center, the firm developed a computerized system that inserts images electronically into TV shows. Before a game, the TV cameras scan the arena and "memorize" features of the park, such as creases in the padded wall behind home plate and other boundaries that define a virtual billboard. When the camera passes those features during the telecast, the system inserts the sign, or the part of it visible in the camera's frame of reference. Ballplayers on the field appear to walk in front of the sign. Ideally, the TV audience will be unable to tell whether the billboard hangs in the ballpark or only in cyberspace. Local sponsors could buy a billboard in a national telecast, and a national advertiser could deliver different messages in each market. Princeton Electronic hopes to make the system available commercially before the baseball season ends this fall." It seems obvious that the RISKS increase as the truth of the picture in the TV medium can be selectively and partially modified. It is difficult enough now for many people to tell whether what is seen on TV is real or fake [note the many similarities between national network TV news, major metropolitan network news and the recreated news in Hard Copy and its several competitors.] R. Peter Jackson, Mariposa Computer Services, 982 Jimeno Road, P. O. Box 149, Santa Barbara, California 93102-0149 USA 1-805.963.4305 ------------------------------ Date: Thu, 16 Jun 1994 11:24:16 -0600 From: jra1854@tntech.edu (Jeffrey Austen) Subject: Misdirected Mail I received the following in the mail the other day. Quite amusing. I wonder if the CIA would send out a similar message if one of their secrets got out? >One of IBM's electronic mail distribution nodes experienced a >problem routing mail from Wednesday June 8, 1994, through >approximately 7:00pm Thursday June 9, 1994. This may have >resulted in your having received proprietary information that >was not intended for you. If you have received such >information, please return it to the Internet address: > xxx@xxx.ibm.com >without retaining any copies of it. If you have already >destroyed or discarded the information, please confirm this by >sending a note to this address stating that the information >you received has been destroyed. > >If you are not sure whether you should have received certain >information or if you have any other questions, please call >xxx xxx at (xxx) xxx-xxxx. Jeffrey Austen, Tennessee Technological University, Box 5004 Cookeville Tennessee 38505 U.S.A. jra1854@tntech.edu (615) 372-3485 ------------------------------ Date: Thu, 16 Jun 94 23:03:48 PDT From: jhoward@sol.uvic.ca (John Howard) Subject: Revenue Canada database allows birthday change Something has just come to light that might be of interest to Risks readers concerning my end of the year taxes here in Canada. For whatever reason, my new accountant (who resides in a different city) filed my tax with a typo on it: my birthday was off by one day. Well, as expected, the system the Feds have sent me a note saying my birthday had changed from the last time I had filed. The form asked me to come down to my local office to correct the error, or if this wasn't an error don't worry about it. How can they say "don't worry about it"? As far as I know people aren't allowed to change their birthday! I chatted with the teller that helped me correct the error. He said that his most memorable error was a situation where a senior had transposed the middle digits of his year of birth to make him younger by decades. The error was caught when the computer found a young person claiming pension benefits. The teller enlightened me by saying that personal data is taken from only the most recent filing. I suppose this would be ok for a change of address or even of name, but of birthday! Imagine your favorite ten risks.... John Howard ------------------------------ Date: Thu, 16 Jun 1994 17:29:40 -0400 (EDT) From: ROBACK@ENH.NIST.GOV Subject: NIST Response to Blaze Attack on Clipper Note: The following material was released by NIST in response to recent articles regarding AT&T/Matt Blaze and the key escrow chip. A second more technical response follows. ------------------------- June 2, 1994 Contact: Anne Enright Shepherd (301) 975-4858 The draft paper by Matt Blaze* describes several techniques aimed at circumventing law enforcement access to key escrowed encryption products based on government-developed technologies. As Blaze himself points out, these techniques deal only with the law-enforcement feature, and in no way reduce the key escrow chips' inherent security and data privacy. -- "None of the methods given here permit an attacker to discover the contents of encrypted traffic or compromise the integrity of signed messages. Nothing here affects the strength of the system from the point of view of the communicating parties...." p. 7. Furthermore, Blaze notes that the techniques he is suggesting are of limited use in real-world voice applications. -- "28 minutes obviously adds too much latency to the setup time for real-time applications such as secure telephone calls." p. 7. -- "The techniques used to implement them do 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." p. 8. Anyone interested in circumventing law enforcement access would most likely choose simpler alternatives (e.g., use other nonescrowed devices, or super encryption by a second device). More difficult and time-consuming efforts, like those discussed in the Blaze paper, merit continued government review -- but they are very unlikely to be employed in actual communications. All sound cryptographic designs and products consider trade-offs among design complexity, costs, time and risks. Voluntary key escrow technology is no exception. Government researchers recognized and accepted that the law enforcement access feature could be nullified, but only if the user was willing to invest substantial time and trouble, as the Blaze report points out. Clearly, the government's basic design objective for key escrow technology was met: to provide users with very secure communications that will still enable law enforcement agencies to benefit from lawfully authorized wiretaps. It is still the only such technology available today. Today, most Americans using telephones, fax machines, and cellular phones have minimal privacy protection. The key escrow technology -- which is available on a strictly voluntary basis to the private sector -- will provide the security and privacy that Americans want and need. * Statements from "Protocol Failure in the Escrowed Encryption Standard," May 20 draft report by Matt Blaze, AT&T Bell Laboratories ----- Note: The following provides additional technical material in response to questions regarding a recent paper by Matt Blaze on key escrow encryption. -------------------------------------- Technical Fact Sheet on Blaze Report and Key Escrow Encryption Several recent newspaper articles have brought attention to a report prepared by Dr. Matthew Blaze, a researcher at AT&T's Bell Labs. These articles characterize a particular finding in Blaze's report as a ~flaw~ in the U.S. government's key escrow encryption technology. None of the findings in Dr. Blaze's paper in any way undermines the security and privacy provided by the escrow encryption devices. The finding which has received the most publicity could allow a non-compliant or ~rogue~ application to send messages to compliant or ~non-rogue~ users which will not be accessible by law enforcement officials through the escrowed encryption standard field called the Law Enforcement Access Field (LEAF). Dr. Blaze's approach uses the openly disclosed fact that the LEAF contains 16-bit checkword to prevent rogue users from modifying the law enforcement access mechanism. This 16-bit checkword is part of the 128-bit LEAF, which also includes the enciphered traffic key and the unique chip identifier. Dr. Blaze's method is to randomly generate different 128-bit LEAFs until he gets one that passes the checkword. It will take on average 216, or 65,536 tries. This is not a formidable task; it could be done in less than an hour. Dr. Blaze questions the adequacy of a 16-bit checkword and suggests using a larger one, to ensure that the exhaustion attack would be so time consuming as to be impractical. The chip designers recognized the strengths and limitations of a 16-bit checkword. Following are the reasons why they chose to use a checkword of only 16 bits: * There were four fundamental considerations that the designers considered in choosing the LEAF parameters. These were: (1) ease of access by authorized law enforcement agencies, (2) impact on communications, (3) a sufficiently large identifier field which would not constrain manufacturers, and (4) the difficulty required to invalidate the LEAF mechanism by techniques such as those described by Dr. Blaze. * The purpose of the LEAF is to preserve law enforcement's ability to access communications in real-time. The encrypted traffic key, which enables them to do this, is 80 bits long. In addition to this 80-bit field, the LEAF must contain the unique identification number of the key escrow encryption chip doing the encryption. * The size of the identifier field was the subject of considerable deliberation. In the earliest considerations it was only 25 bits long. The chip designers recognized that 25 bits did not offer enough flexibility to provide for multiple manufacturers of key escrow devices. Different chip manufacturers would need manufacturer identifiers as well as their own chip identifiers to ensure that identifiers are unique. Eventually, the designers agreed that 32 bits would adequately meet this requirement. * In many environments, error-free delivery of data is not guaranteed, and there is considerable concern by communication engineers that requiring error-free transmission of a fixed field (the LEAF) could make the encryption device difficult to use. In early discussions with industry, they were opposed to any checkword. In the end, they agreed it would be acceptable if the size of the LEAF was restricted to 128 bits. This left 16 bits for a checkword to inhibit bypassing the LEAF. While recognizing the possibility of exhausting these 16 bits, the designers concluded that 16 bits are adequate for the first intended application. Security enhancements are being made for other applications, such as the TESSERA card. Note that computations are required to search for a matching checkword, which then has to be properly substituted into the communications protocol. The performance and cost penalties of the search operation are significant for telephone, radio, and other such applications, thus providing adequate protection against this technique for bypassing the LEAF. In summary: * Although this technique would allow one to bypass the LEAF, the security provided by the escrow encryption devices would not be altered. Users' information would still be protected by the full strength of the encryption algorithm. * Dr. Blaze was accurate in noting that these attacks are of limited effectiveness in real-time telephony. * When designing the key escrow chip, NSA emphasized sound security and privacy, along with user friendliness. The attacks described by Dr. Blaze were fully understood at the time of initial chip design. The use of 16 bits for the checkword was an appropriate choice in view of the constraints of a 128-bit LEAF. It provides excellent security for real-time telephone applications with high assurance that law enforcement's interests are protected. * Dr. Blaze's research was done using prototype TESSERA cards. As part of the family of planned releases/upgrades, NSA already has incorporated additional security safeguards into the production TESSERA cards to protect against the kinds of attacks described by Dr. Blaze. ------------------------------ Date: Thu, 16 Jun 94 12:26:55 GMT From: rlvd_cif@uhura.cc.rochester.edu (Rob Levandowski) Subject: ROLM phones and "Do Not Disturb": how to lose calls Here at the University of Rochester, students are given ROLMphone 120DCMs in their rooms. These phones (or, more precisely, the digital switch that they are connected to) have a function called "do not disturb". When the appropriate code is entered into the keypad, the line is put into DND mode, and it -will not ring- for any reason. However, if someone tries to call, they hear ringing. There are two problems with the implementation of this feature. First, the code to activate and de-activate the feature is anything but intuitive. Having lived off-campus for a while, I forget the exact code, but it is along the lines of #6x. The code for speed-dialing numbers is #3x. On more than one occasion I meant to hit a speed-dial and instead activated do-not-disturb. This wouldn't be a big problem... except that there is no indication whatsoever that you are in DND mode. No lights, no tones, no message to callers. I missed calls for days the first time I did this... and a lot of people got concerned because I "was never home". This system should at the least have some sort of different dialtone or indicator light to show that you won't be getting any calls. (God knows the ROLM 120 has enough blinky-lights...) Likewise, since the switch is equipped with PhoneMail, it would be nice if it could give an announcement... "The party you have dialed is not accepting calls at this time." The privacy may be nice when you're using your dorm room for, shall we say, after-hours social research ;) -- but if you're forgetful like me, the implementation is pretty troublesome. Rob Levandowski, Computer Interest Floor associate / University of Rochester macwhiz@cif.rochester.edu ------------------------------ Date: Thu, 16 Jun 94 19:45:06 BST From: Pete Mellor Subject: A320 hull losses: Lies, damned lies and statistics This thread of the discussion was originally started by Wesley Kaplow in RISKS DIGEST 16.15 under the title: "Does it matter why A3??'s have a poor record?" To recap, Wesley said (without citing a source): > Already, Airbus Industry has lost more planes per delivered plane > than other major aircraft manufacturer in the past 3 decades (Lockheed, > Boeing, MD). I contradicted this in RISKS 16.16, citing a table of statistics from an article entitled ``Der Traum von Total Sicherheit'' ["The Dream of Total Safety"], in the German magazine Focus, 38, 1993, pp18-21, and Wesley has since agreed that his statement requires support (see his follow-up mailings). The table was as follows:- >Aircraft No. in Hulls % Losses >Type Service Lost > >DC-9/MD-80 2065 68 3.29 >Boeing 727 1831 62 3.39 >Boeing 737 2515 57 2.27 >Boeing 747 988 22 2.23 >DC-10 446 21 4.71 >Airbus A300/310 636 7 1.10 >Airbus A320 411 4 0.97 Focus magazine cited "Luftfahrtindustrie" (NOTE: not "Lundfahrtindustrie", as I originally transcribed it) as the source. Since then, I have been jumped on from a great height by several RISKS contributors who have accused me of abusing statistics. Since this is not something I do deliberately, I would like to make the following points (taking into account the various objections raised by those who have written to me):- 1. I am well aware that the statistics above are incomplete. They do not allow for the total operating time of each type. They do not distinguish between losses due to on-board system failure and losses due to other causes which could not possibly be blamed on the manufacturer (e.g., the Lockerbie bombing, the Vincennes shoot-down). They do not take account of wear-out and natural retirement, so that the number shown may be the "number sold" and not the "number in service". I quoted them because they were all I had at the time (while being acutely aware of their imperfections). 2. Wesley's original statement *is*, however, refuted by these statistics *provided they are correct* (see point 3). A secondary question arises: "Is this a meaningful measure of the safety of a type of aircraft?" I will return to this in point 4. 3. Peter Ladkin pointed out to me that the source name that I had originally misread as "Lundfahrtindustrie" and assumed to be some official body which records air accident statistics, is in fact "Luftfahrtindustrie" (well, it was in small print! :-) and means simply "Air Travel Industry". In other words, the source cited by Focus magazine is totally vague, and (as Peter said) about as authoritative as "I read it on the net"! :-) The statistics I naively quoted therefore need substantiation. 4. What would convince Joe Public that a given aircraft type was safe to fly? There are several possible measures of the safety of an aircraft design (note: I do *not* pretend that this list is exhaustive):- a) Deaths per passenger mile on the given type. This is used by the aircraft manufacturing industry. Conclusion: air travel is the safest way of going anywhere. b) Deaths per passenger *hour* on the given type. This makes flying about as safe as driving, but the risk would seem to be tolerable, since a probability of 10^-4 per year of dying in a road accident doesn't seem to worry most people (figures based on official UK statistics). c) Crashes (i.e., hull write-off) per revenue flight hour. This is used by the certification agencies (FAA, JAA, etc.) when awarding an airworthiness type certificate. The target is a maximum probability of loss of aircraft of 10^-6 per flight hour due to *all* causes. Historically, statistics show that *system-related* causes account for 1 in 10. The conservative assumption that there are 100 critical systems on board then leads to the famous 10^-9 requirement for probability of failure of an individual flight-critical system. d) Crashes per cycle (take-off plus landing). e) Crashes per example delivered (which is where we came in! :-) f) Passenger deaths per cycle. g) Serious incidents per flight hour or per cycle. (Q: "How many accidents has the A320 had?" A: "Five - You forgot about Lille, where an A320 landed on top of a Mooney, taking off both its wings and the empennage, and collapsing the A320's front gear. Since nobody was hurt, it doesn't count, or does it?") The whole picture is confused by the fact that the public perception of risk is biased *against* rare events that kill lots of people, and less against common events that kill a few. (In assessing any event that loses the aircraft, you must assume the worst case: that you kill everyone on board. If you crash a car, it's just you and the guy you hit!) I don't pretend to give an answer here, simply raise a few pertinent questions, whose answers (IMHO) are far from obvious. 5. A fairer comparison would be between the A320 and competing aircraft *of the same generation*. I would like to thank Robert Dorsett for the following:- 757 = 0 in eleven years. 767 = 1 in twelve years. (Lauda) A320 = 4 in five years. (Air France, Indian Airlines, Air Inter, Lufthansa) 6. Given that all the statistics above are deficient (basically, they lack an exposure time base), they do still tell us *something*. (In considering a fleet above a certain size, we could assume roughly the same operating hours per day for each example, and things like maintenance time, etc., would average out.) We could *tentatively* conclude that the A320 is a long way from being a flying coffin, but also a long way from being the safest aircraft ever, or even as safe as it should be, given its modernity. The public perception of the A320 seems to be that it is the most dangerous thing that ever left the ground. IMHO this is wrong, and we should be careful not to spread false alarm. There are, of course, better statistics (e.g., from Flight International) and I shall attempt to locate a few. The best come from the air insurance industry, but I am not sure that I can get my grubby paws on those for reasons of confidentiality. In the meantime, if anyone knows of a good source ... :-) Also, how can I phrase an argument to convince my mother that I stand a greater chance of being run over crossing St. Johns Road while walking from Farringdon tube station to the University than I do of dying in an air crash? Then I won't have to make long distance 'phone calls from the airport in B*m***k Egypt to tell her we landed safely every time I go to a conference! :-) Peter Mellor, Centre for Software Reliability, City University, Northampton Sq London EC1V 0HB +44 (71) 477-8422 p.mellor@csr.city.ac.uk ------------------------------ Date: 31 May 1994 (LAST-MODIFIED) From: RISKS-request@csl.sri.com Subject: Info on RISKS (comp.risks), contributions, subscriptions, FTP, etc. The RISKS Forum is a moderated digest. Its USENET equivalent is comp.risks. Undigestifiers are available throughout the Internet, but not from RISKS. 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