Privacy on the Line

A penetrating and insightful study of privacy and security in telecommunications for a post-9/11, post-Patriot Act world. Telecommunication has never been perfectly secure. The Cold War culture of recording devices in telephone receivers and bugged embassy offices has been succeeded by a post-9/11 world of NSA wiretaps and demands for data retention. Although the 1990s battle for individual and commercial freedom to use cryptography was won, growth in the use of cryptography has been slow. Meanwhile, regulations requiring that the computer and communication industries build spying into their systems for government convenience have increased rapidly. The application of the 1994 Communications Assistance for Law Enforcement Act has expanded beyond the intent of Congress to apply to voice over Internet Protocol (VoIP) and other modern data services; attempts are being made to require ISPs to retain their data for years in case the government wants it; and data mining techniques developed for commercial marketing applications are being applied to widespread surveillance of the population. In Privacy on the Line, Whitfield Diffie and Susan Landau strip away the hype surrounding the policy debate over privacy to examine the national security, law enforcement, commercial, and civil liberties issues. They discuss the social function of privacy, how it underlies a democratic society, and what happens when it is lost. This updated and expanded edition revises their original—and prescient—discussions of both policy and technology in light of recent controversies over NSA spying and other government threats to communications privacy

SMS4 Encryption Algorithm for Wireless Networks

SMS4 is a Chinese block cipher standard, mandated for use in protecting wireless net- works, and issued in January 2006. The input, output, and key of SMS4 are each 128 bits. The algorithm has 32 rounds, each of which modifies one of the four 32-bit words that make up the block by xoring it with a keyed function of the other three words. Encryption and decryption have the same structure except that the round key schedule for decryption is the reverse of the round key schedule for encryption

New directions in cryptography.

Abstract Two kinds of contemporary developments in cryp-communications over an insecure channel order to use cryptogtography are examined. Widening applications of teleprocess-raphy to insure privacy, however, it currently necessary for the ing have given rise to a need for new types of cryptographic communicating parties to share a key which is known to no systems, which minimize the need for secure key distribution one else. This is done by sending the key in advance over some channels and supply the equivalent of a written signature. This secure channel such a private courier or registered mail. A paper suggests ways to solve these currently open problems. private conversation between two people with no prior acquainIt also discusses how the theories of communication and compu-tance is a common occurrence in business, however, and it is tation are beginning to provide the tools to solve cryptographic unrealistic to expect initial business contacts to be postponed problems of long standing. long enough for keys to be transmitted by some physical means. The cost and delay imposed by this key distribution problem is a major barrier to the transfer of business communication

New directions in cryptography.

Abstract Two kinds of contemporary developments in cryp-communications over an insecure channel order to use cryptogtography are examined. Widening applications of teleprocess-raphy to insure privacy, however, it currently necessary for the ing have given rise to a need for new types of cryptographic communicating parties to share a key which is known to no systems, which minimize the need for secure key distribution one else. This is done by sending the key in advance over some channels and supply the equivalent of a written signature. This secure channel such a private courier or registered mail. A paper suggests ways to solve these currently open problems. private conversation between two people with no prior acquainIt also discusses how the theories of communication and compu-tance is a common occurrence in business, however, and it is tation are beginning to provide the tools to solve cryptographic unrealistic to expect initial business contacts to be postponed problems of long standing. long enough for keys to be transmitted by some physical means. The cost and delay imposed by this key distribution problem is a major barrier to the transfer of business communication

The Risks of Key Recovery, Key Escrow, and Trusted Third-Party Encryption

A variety of "key recovery," "key escrow," and "trusted third-party" encryption requirements have been suggested in recent years by government agencies seeking to conduct covert surveillance within the changing environments brought about by new technologies. This report examines the fundamental properties of these requirements and attempts to outline the technical risks, costs, and implications of deploying systems that provide government access to encryption keys

The Risks of Key Recovery, Key Escrow, and Trusted Third-Party Encryption

A variety of "key recovery," "key escrow," and "trusted third-party" encryption requirements have been suggested in recent years by government agencies seeking to conduct covert surveillance within the changing environments brought about by new technologies. This report examines the fundamental properties of these requirements and attempts to outline the technical risks, costs, and implications of deploying systems that provide government access to encryption keys

Bugs in our Pockets: The Risks of Client-Side Scanning

Our increasing reliance on digital technology for personal, economic, and government affairs has made it essential to secure the communications and devices of private citizens, businesses, and governments. This has led to pervasive use of cryptography across society. Despite its evident advantages, law enforcement and national security agencies have argued that the spread of cryptography has hindered access to evidence and intelligence. Some in industry and government now advocate a new technology to access targeted data: client-side scanning (CSS). Instead of weakening encryption or providing law enforcement with backdoor keys to decrypt communications, CSS would enable on-device analysis of data in the clear. If targeted information were detected, its existence and, potentially, its source, would be revealed to the agencies; otherwise, little or no information would leave the client device. Its proponents claim that CSS is a solution to the encryption versus public safety debate: it offers privacy -- in the sense of unimpeded end-to-end encryption -- and the ability to successfully investigate serious crime. In this report, we argue that CSS neither guarantees efficacious crime prevention nor prevents surveillance. Indeed, the effect is the opposite. CSS by its nature creates serious security and privacy risks for all society while the assistance it can provide for law enforcement is at best problematic. There are multiple ways in which client-side scanning can fail, can be evaded, and can be abused.Comment: 46 pages, 3 figure