Here is Dorothy Denning's reply to my response to her Newsday article. The shocking features are that she does not seem able to differentiate legality from morality, and doesn't seem to believe that law should flow from a popular majority, but from the state. Sure sounds like she wants a police state to me. Steve Blasingame bsteve@zontar.com -------------------- From daemon Mon Feb 28 09:06:58 1994 Date: Mon Feb 28 11:25:34 -0500 1994 From: netcomsv!chair.cosc.georgetown.edu!denning Subject: Re: Newsday Editorial To: internet!attmail!zontar!bsteve Reply-To: netcomsv!chair.cosc.georgetown.edu!denning (Dorothy Denning) Thanks for your comments. I have tried to address the law enforcement issues you raised in a more thoughtful way in the attached. Dorothy Denning --------------- Encryption and Law Enforcement Dorothy E. Denning Georgetown University February 21, 1994 Summary Although encryption can protect information from illegal access, it can also interfere with the lawful interception of communications by government officials. The goal of this report is to describe the effect of encryption technology and the government's new Escrowed Encryption Standard [EES] on law enforcement, mainly from the perspective of law enforcement. The information presented here was obtained from public documents and testimonials by law enforcement officials, from private conversations with people in the FBI and other law enforcement agencies, and from comments I received by people in law enforcement on an earlier version of this report. Some of this research was performed in conjunction with my earlier study of the FBI's proposal on Digital Telephony [DT, Denning]. The following summarizes the key points, which are discussed in greater depth in the sections that follow: 1. The need for wiretaps: Court-authorized interception of communications is essential for preventing and solving many serious and often violent crimes. Electronic surveillance not only provides information that often cannot be obtained by other means, but it yields evidence that is considerably more reliable and probative than that obtained by most other methods of investigation. No other investigative method can take its place. 2. The threat of encryption to lawful surveillance: Because encryption can make communications immune from lawful interception, it threatens a key law enforcement tool. The proliferation of high quality, portable, easy-to-use, and affordable encryption could be harmful to society if law enforcement does not have the means to decrypt lawfully intercepted communications. Although encryption of stored files is also of concern, 99% of the issue is telephone communications (voice, fax, and data). 3. Digital Telephony: Encryption is not the only threat to lawful electronic surveillance. Advances in telecommunications also threaten the ability of law enforcement to conduct authorized interceptions. 4. Encryption policy and the EES: The government's Escrowed Encryption Standard offers a balanced solution to the encryption problem that takes into account the equities of public safety, effective law enforcement, and national security along with those of privacy, security, and industry success. The technology and accompanying procedures provide strong encryption and a high level of security, while accommodating the need for real-time or near real-time decryption of intercepted communications. The program is the best known solution, at least for the intended initial application, mainly voice, fax, and data encryption over the public switched network. 5. Criminal use of Non-EES Encryption: Although some criminals may seek to use other forms of encryption, the escrowed encryption standard may succeed and become ubiquitous as the chief form of encryption, making it much harder for criminals to evade interceptions by using non-standard, non-interoperable encryption. 6. International problem: The impact of encryption on law enforcement is an international problem. The U.S. government exercised strong leadership by recognizing the problem and developing a solution before it becomes serious. 1. The Need for Wiretaps Law enforcement views court-authorized interception of communications as essential for preventing and solving many serious and often violent crimes, including terrorism, organized crime, drugs, kidnaping, major white collar crime brought against the government, and political corruption [DT, DT Cases, Kallstrom]. In testimony before the Computer Systems Security and Privacy Board, James Kallstrom, former Chief of the FBI's Engineering Section, estimated that wiretaps are used in excess of 90% of all cases involving terrorism, often with the result of preventing a terrorist act. For example, in a Chicago case code-named RUKBOM, the FBI successfully prevented the El Rukn street gang, which was acting on behalf of the Libyan government, from shooting down a commercial airliner using a stolen military weapons system [Kallstrom, DT Cases]. Examples of other terrorist attacks successfully prevented with the help of electronic surveillance include the bombing of a foreign consulate in the U.S. and a rocket attack against a U.S. ally. Electronic surveillance is used against organized crime, widespread fraud, bribery, and extortion. It was used to help solve a case involving corruption associated with organized crime control of the International Longshoremen's Union, which cost the citizens of New York city 10-12 cents on every dollar spent on consumer items coming through the port of New York, and to help solve another case involving organized crime control over the construction trade of New York City, which had led to 3-5% of all construction contracts being escalated by that percentage [Kallstrom]. Evidence obtained from electronic surveillance in a case involving the Concrete and Cement Workers Union prevented an economic loss to the public of $585 million [DT Cases]. According to the FBI, the hierarchy of La Cosa Nostra has been neutralized or destabilized through the use of electronic surveillance, and thirty odd years of successes would be reversed if the ability to conduct court-authorized electronic surveillance was lost. Almost two thirds of all court orders for electronic surveillance are used to fight the war on drugs, and electronic surveillance has been critical in identifying and then dismantling major drug trafficking organizations. In an operation code named "PIZZA CONNECTION," an FBI international investigation into the importation and distribution of $1.6 billion worth of heroin by the Sicilian Mafia and La Cosa Nostra resulted in the indictment of 57 high-level drug traffickers in the U.S. and 5 in Italy [DT Cases]. The FBI estimates that the war on drugs and its continuing legacy of violent street crime would be substantially, if not totally, lost if law enforcement were to lose its capability for electronic surveillance. Wiretaps are used for cases involving murders and kidnapings. As the result of wiretaps, sufficient evidence was obtained to arrest and convict a serial-murderer who had been operating for three to four years, and to locate and subsequently convict two other persons who had been involved with the murders [DT Cases]. By intercepting voice, fax, and communications on a local bulletin board system, the FBI prevented the proposed kidnaping and murder of a young child for the purpose of making a "snuff murder" film [Kallstrom]. Through wiretaps, the FBI prevented a group from bombing a man's house and killing him and his family [Kallstrom]. Electronic surveillance has been used to investigate aggravated governmental fraud and corruption. A recent military-procurement fraud case ("Ill-Wind") involving persons in the Department of Defense and defense contractors has so far led to 64 convictions and about $260 million in fines, restitutions, and recoveries ordered. In another case, U.S.District Court Judge Robert Collins was convicted of soliciting and accepting bribes [DT Cases]. John Kaye, Prosecutor for Monmouth County, New Jersey, reported that almost every police officer indicted in his county has been indicted because of a wiretap [Kaye]. In the decade from 1982 to 1991, state and federal agencies were granted 7,467 court orders for interceptions under Title III of the Omnibus Crime Control and Safe Streets Act and equivalent state statutes. At the end of 1991, these had led to 35,851 arrests and 19,259 convictions. Convictions resulting from interceptions conducted in the last few years are still accumulating, as trials regarding those subjects are held. Because the number of arrests associated with wiretaps is a small fraction of all arrests each year, some people have questioned whether wiretaps are necessary or worthwhile given the availability of other investigative techniques. By law, wiretapping cannot be used if other methods of investigation could reasonably be used instead. Such normal investigative methods usually include visual surveillance, interviewing subjects, the use of informers, telephone record analysis, and Dialed Number Recorders (DNRs). However, these techniques often have limited impact on an investigation. Continuous surveillance by police can create suspicion and therefore be hazardous; further, it cannot disclose the contents of telephone conversations. Questioning identified suspects or executing search warrants at their residence can substantially jeopardize an investigation before the full scope of the operation is revealed, and information can be lost through interpretation. Informants are useful and sought out by police, but the information they provide does not always reveal all of the players or the extent of an operation, and great care must be taken to ensure that the informants are protected. Moreover, because informants are often criminals themselves, they may not be believed in court. Telephone record analysis and DNRs are helpful, but do not reveal the contents of conversations or the identities of parties. Other methods of investigation that may be tried include undercover operations and stings. But while effective in some cases, undercover operations are difficult and dangerous, and stings do not always work. Law enforcers claim that no other method can take the place of wiretaps [Kallstrom]. Each court order must provide evidence for the need to wiretap by demonstrating that normal investigative procedures have been tried and have failed or reasonably appear unlikely to succeed or would be too dangerous [USC 18, DDKM]. This does not mean that the other methods are not used in those cases, as indeed they are, but only that they are inadequate to successfully investigate and prosecute the cases. Wiretaps not only provide information that cannot be obtained by other means, but yield evidence that is considerably more reliable and probative than that obtained by most other methods of investigation. A wiretap is also less dangerous than sending in a civilian informant or undercover agent who is wired since the risk of discovery puts that person's life in jeopardy. Finally, a wiretap may be less invasive of privacy than placing a bug in a subject's home or using an undercover agent to establish an intimate relationship with the subject. Although the number of arrests from wiretaps is relatively small compared to the total of all arrests, those criminals that are arrested and convicted with the aid of wiretaps are often the leaders of major organized crime, drug trafficking, and terrorist groups. In reviewing a proposal for a wiretap, law enforcement agencies determine whether the subjects of the proposed interception are worthy targets of investigation and whether the interception is worth doing. The law enforcement community views electronic surveillance as essential to effective law enforcement, and law enforcement as essential not only to public safety and our economic well-being, but to a free society. In his remarks at the Computer Ethics Conference, Alan McDonald of the FBI summed it up: "We have been fortunate as a society to enjoy unparalleled freedom. It has resulted because we live under a compact of ordered liberty. One need only consider the number of countries where law enforcement is ineffective and where the violence and corruption of organized crime reign to see true diminishments of freedom, liberty, and personal privacy" [McDonald]. 2. The Threat of Encryption to Lawful Surveillance Encryption has been available to criminals for a long time. Until recently, however, voice encryptors were extremely bulky and the quality of the voice low, so criminals who tried encryption would typically cease using it [Kallstrom]. But recent advances in encryption technology are leading to products such as the AT&T 3600 Telephone Security Device that are small, portable, easy-to-use, affordable, and have high quality audio. Law enforcers expect that criminals will flock to such devices, not only to hide their communications from the government, but to safeguard them from their competitors [Kallstrom, Meeks]. The effect could be that criminals are able to make their communications immune from government search and seizure even under probable cause of criminal activity. The proliferation of such encryption products ultimately could be harmful to society if government officials do not have the means to decrypt lawfully intercepted communications, at least in most cases. On behalf of the National District Attorney's Association, President Robert Macy writes: "In an increasingly dangerous world, law enforcement cannot afford to be blindfolded by advanced technologies including encryption devices" [Macy]. Roy Kime, Legislative Counsel for the International Association of Chiefs of Police, makes the analogy that people in law enforcement are being "outgunned" by the criminals with respect to advances in technology [Kime]. In testimony before Congress, Donald Delaney, Senior Investigator with the New York State Police, said he believed that if we adopted an encryption standard that did not permit lawful intercepts, we would have havoc in the United States [Delaney]. Although there are no "dead bodies" as yet, Kallstrom believes there will be a "horror show" if the encryption that proliferates in the market does not factor in an equity for law enforcement [Kallstrom]. Criminals can use encryption to conceal stored information as well as communications. In a child pornography case on the West coast, encrypted data files have slowed down the investigation of a large international ring dealing with child pornography and the possible smuggling of children [Kallstrom]. However, although law enforcement is concerned about the use of encryption to conceal computer files, their primary concern is with communications, particularly telephone conversations. This is because intercepts play a much more important role in investigations than documents. Real-time intercepts pick up the criminal dialogue, the plotting and planning that glues crimes together. By revealing conversations about possible future activities, wiretaps also may be used to prevent crimes from occurring. Thus, while being able to decrypt files is valuable, 99% of the issue today is telephone conversations [Kallstrom]. In addition, while communications over high speed computer networks are expected to become an issue, the primary concern today is with voice, fax, and data over the public switched network (telephone system). 3. Digital Telephony Encryption is not law enforcement's only concern about wiretaps. They are also concerned about changes in telecommunications technologies. Many of the new digital-based technologies and services such as ISDN, fiber optic transmissions, and the increasing number of mobile telecommunication networks and architectures cannot be tapped using the traditional methods used to intercept analogue voice communications carried over copper wire. In addition, increases in transmission speed have made interceptions more difficult. Although it is technically feasible to intercept the new communications, not all systems have been designed or equipped to meet the intercept requirements of law enforcement. According to the FBI, numerous court orders have not been sought, executed, or fully carried out because of technological problems. To address these problems, the Department of Justice proposed Digital Telephony legislation [DT] that would require service providers and operators to meet their statutory assistance requirements by maintaining the capability to intercept particular communications. So far, the proposal has not been introduced in Congress. 4. Encryption Policy and the EES Law enforcement seeks an encryption policy that takes into account the equities of public safety, effective law enforcement, and national security along with those of privacy, security, and industry success [Kallstrom]. They support the use of encryption by law abiding citizens and organizations to protect sensitive information, and recognize the importance of encryption to safeguarding information assets [Settle]. They generally favor strong encryption over weak or "dumbed down" encryption [Kallstrom]. To implement lawful interceptions of encrypted communications, they need a real-time or near real-time decryption capability in order to keep up with the traffic and prevent potential acts of violence. Since there can be hundreds of calls a day on a tapped line, any solution that imposes a high overhead per call is impractical. These requirements for strong encryption and near real-time decryption led to the Escrowed Encryption Standard [EES] and its related key escrow system. Upon receiving a chip's unique key components from the two escrow agents, law enforcers can readily decrypt all conversations encrypted with the chip until the wiretap terminates, at which time all chip-related keys are destroyed. The escrow agents need not get involved in the decryption of each conversation, which would be overly cumbersome. Law enforcers consider the EES to be the best known approach for addressing the dual need for secure communications and court-ordered access, at least for the intended initial application, namely voice, fax, and data encryption of telephone communications transmitted over the public switched network. The EES will significantly enhance communications security by making strong encryption available in a way that makes illegal wiretaps virtually impossible, while permitting those that are lawfully authorized. The key escrow mechanisms and procedures are being designed to provide a high level of protection for keys and to protect against compromises or abuses of keys, thereby assuring that no person or entity, including government, can improperly access one's EES communications. Although there is no evidence of widespread abuse of wiretaps by law enforcement officials, the EES will effectively thwart any potential abuse, thereby providing greater protection from illegal government wiretaps than currently exists. The Presidential Decision Directive [PDD] on escrowed encryption is viewed as offering a balanced solution to the encryption problem that is consistent with basic tenets found in the Constitution and in the Bill of Rights, which does not grant an absolute right to privacy, but rather seeks to balance individual privacy with the need to protect society as a whole [McDonald]. William A. Bayse, Chief Scientist of the FBI, observed: "It is well recognized that Anglo-American law has historically balanced the personal privacy of the individual with the legitimate needs of Government. ... As can be seen from a review of the Fourth Amendment to the U.S. Constitution ..., an individual's privacy rights are not absolute, and they give way to more compelling Governmental rights when criminality is demonstrated or suspected." [Bayse]. Similarly, Alan McDonald noted "... the dictum of the Bill of Rights, and the Fourth Amendment in particular, is a balance between individual liberty and privacy and the legitimate need of Government to protect society as a whole -- a balance to prevent the tyranny of absolutist Government and the tyranny of lawlessness and anarchy. ... The electronic surveillance statutes, like the Fourth Amendment, are founded on the concept of balancing fundamental individual and governmental interests -- personal privacy and the public safety. ... Encryption technology creates no legal rights under our Constitution, the Fourth Amendment, or under our electronic surveillance statutes" [McDonald]. 5. Criminal Use of Non-EES Encryption Some people have argued that criminals will not use EES, but rather will use encryption methods that defeat law enforcement. While acknowledging that some criminals may use other means, law enforcers assume most vendors will not manufacture an encryption device unless they perceive a large, legal market [Kallstrom]. The hope is that the EES, or some other approach that takes into account the law enforcement equities, will proliferate in the legitimate encryption market in this country and become transparent, thereby cutting down on the availability and use of encryption that does not include the law enforcement equities [Kallstrom]. There is some evidence that through market forces and government purchasing power, the EES may become the de facto national standard for telephone encryption. When AT&T announced its 3600 Telephone Security Device in Fall 1992, the device used a DES chip for encryption, and did not include a capability for law enforcement access. Priced at $1200, it would have been attractive to criminals, and could have led to the promulgation of encryption technology that would have posed a major threat to law enforcement. However, when the government announced the key escrow initiative on April 16, 1993, AT&T simultaneously announced that the TSD would use instead the new Mykotronx MYK-78 chip, aka "Clipper", which uses the EES. The government ordered several thousand of the modified devices. Since EES products can be exported to most places, there is an additional incentive for vendors to incorporate the EES into their products rather than, say, the DES, which is subject to stricter export controls. However, there are other factors relating to the nature of the technology and to public acceptance that could interfere with widespread adoption of EES by vendors. Criminals need to talk with many people outside their circle in order to carry out their activities, for example to rent or purchase needed goods and services. To conduct those conversations, which may be incriminating, they will either need to use an encryption method identical to that used by the other parties or else forego encryption entirely. Assuming EES dominates in the legitimate market, criminals may prefer to use it over communicating in the clear since the EES will at least protect them from their competitors. Criminals are often sloppy in protecting their conversations from law enforcement, making incriminating statements over the phone while acknowledging their phones may be tapped. Even if criminals do not use the EES, the government's objective of making strong encryption available to the public in a way that is not harmful to society will be achieved. Criminals will not be able to take advantage of the strong algorithm to thwart law enforcement. Since it is extremely difficult to develop high quality, strong encryption products, law enforcement may be able to access many non-EES encrypted criminal communications. 6. An International Problem The impact of encryption on effective law enforcement is an international problem, and U.S. law enforcers have observed other countries looking at solutions based on "dumbing down" the encryption or on key escrow. The U.S. government exercised strong leadership by recognizing the problem and developing a solution before it became serious. While the U.S. solution will not necessarily provide an international solution, it as a starting point for solving a global problem. References [Bayse] Bayse, William A., Written statement presented at Part I of the Forum on Rights and Responsibilities of Participants in Networked Communities, panel on Privacy and Proprietary Interests, Computer Science and Telecommunications Board, National Research Council, October 1992. [Delaney] Delaney, Donald P., statement in "Hearings before the Subcommittee on Telecommunications and Finance of the Committee on Energy and Commerce, House of Representatives," June 9, 1993; Serial No. 103-53, pp. 163-164. [DDKM] Delaney, Donald P; Denning, Dorothy E.; Kaye, John; and McDonald, Alan R., "Wiretap Laws and Procedures: What Happens When the Government Taps a Line," September 23, 1993; available from Georgetown University, Department of Computer Science, Washington DC, or by anonymous ftp from cpsr.org as cpsr/privacy/communications/wiretap/ denning_wiretap_procedure.txt. [EES] "Escrowed Encryption Standard," Federal Information Processing Standard Publication (FIPS PUB) 185, National Institute for Standards and Technology, 1994. [Denning] Denning, D. E., "To Tap or Not to Tap," Comm. of the ACM, Vol. 36, No. 3, March 1993, pp. 25-35, 42-44. [DT] "Digital Telephony," U.S. Department of Justice, Federal Bureau of Investigation. [DT Cases] "Digital Telephony Case Examples," distributed with press packet for Presidential Decision Directive on "Public Encryption Management." [Kallstrom] Kallstrom, James K., Presentation at the Computer System Security and Privacy Advisory Board Meeting, National Institute of Standards and Technology, July 29, 1993. [Kaye] Kaye, John, Presentation at the Computer System Security and Privacy Advisory Board Meeting, National Institute of Standards and Technology, July 29, 1993. [Kime] Kime, Roy, Presentation at the Computer System Security and Privacy Advisory Board Meeting, National Institute of Standards and Technology, July 29, 1993. [Macy] Macy, Robert H., Letter submitted to the Computer System Security and Privacy Advisory Board on behalf of the National District Attorneys Association for June 2-4 Meeting, May 27, 1993. [McDonald] McDonald, Alan R., Written statement presented at 2nd National Computer Ethics Conference, April 29, 1993. [Meeks] Meeks, Bud, Presentation at the Computer System Security and Privacy Advisory Board Meeting, National Institute of Standards and Technology, July 29, 1993. [PDD] Presidential Decision Directive on "Public Encryption Management," and Statement by the Press Secretary, The White House, April 16, 1993. [Settle] Settle, James C., Presentation at INFOEXPO '93, Information Security and Virus Prevention Conference and Exhibition, National Computer Security Association, June 11, 1993. [USC 18] Title 18 USC, Sections 2510-2521. (These sections codify Title III of the Omnibus Crime Control and Safe Streets Act of 1968, as amended by the Electronic Communications Privacy Act of 1986.) ------------------------