The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
Nick Mathewson - One of the best experts on this subject based on the ideXlab platform.
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Reputation in P2P Anonymity Systems
2003Co-Authors: Roger Dingledine, Nick Mathewson, Paul SyversonAbstract:Decentralized anonymity systems tend to be unreliable, because users must choose nodes in the network without knowing the entire state of the network. Reputation systems promise to improve reliability by predicting network state. In this paper we focus on Anonymous Remailers and Anonymous publishing, explain why the systems can benefit from reputation, and describe our experiences designing reputation systems for them while still ensuring anonymity. We find that in each example we first must redesign the underlying anonymity system to support verifiable transactions
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Mixminion: Design of a Type III Anonymous Remailer Protocol
2003Co-Authors: George Danezis, Roger Dingledine, Nick MathewsonAbstract:We present Mixminion, a message-based Anonymous remailer protocol with secure single-use reply blocks. Mix nodes cannot distinguish Mixminion forward messages from reply messages, so forward and reply messages share the same anonymity set. We add directory servers that allow users to learn public keys and performance statistics of participating Remailers, and we describe nymservers that provide long-term pseudonyms using single-use reply blocks as a primitive. Our design integrates link encryption between Remailers to provide forward anonymity. Mixminion works in a real-world Internet environment, requires little synchronization or coordination between nodes, and protects against known anonymity-breaking attacks as well as or better than other systems with similar design parameters. 1. Overview Chaum first introduced Anonymous Remailers over 20 years ago [7]. The research community has since introduce
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Mixminion: Design of a Type III Anonymous Remailer Protocol
2003Co-Authors: George Danezis, Roger Dingledine, Nick MathewsonAbstract:We present Mixminion, a message-based Anonymous remailer protocol with secure single-use reply blocks. Mix nodes cannot distinguish Mixminion forward messages from reply messages, so forward and reply messages share the same anonymity set. We add directory servers that allow users to learn public keys and performance statistics of participating Remailers, and we describe nymservers that provide long-term pseudonyms using single-use reply blocks as a primitive. Our design integrates link encryption between Remailers to provide forward anonymity. Mixminion works in a real-world Internet environment, requires little synchronization or coordination between nodes, and protects against known anonymity-breaking attacks as well as or better than other systems with similar design parameters. 1. Overview Chaum first introduced Anonymous Remailers over 20 years ago [7]. The research community has since introduced many new designs and proofs [1, 14, 16, 19, 28, 29], and discovered a variety of new attacks [3, 5, 6, 9, 23, 35]. But because many of the newer designs require considerable coordination, synchronization, bandwidth, or processing resources, deployed Remailers still use Cottrell's Mixmaster design from 1994 [8, 26]. Here we describe Mixminion, a protocol for asynchronous, loosely federated Remailers that maintains Mixmaster's flexibility while addressing the following flaws: Replies: Mixmaster does not support replies or Anonymous recipients --- people who want these functions must use the older and less secure Cypherpunk Type I remailer design [31], which is vulnerable to replay attacks. We introduce a new primitive called a singleuse reply block (SURB), which makes replies as secure as forward messages. Furthermore in Mixminion the Remailers themselves cannot disting..
Peter Wayner - One of the best experts on this subject based on the ideXlab platform.
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chapter 10 Anonymous Remailers
Disappearing Cryptography (Third Edition)#R##N#Information Hiding: Steganography & Watermarking, 2009Co-Authors: Peter WaynerAbstract:Publisher Summary On the Internet, Anonymous Remailers are one solution for letting people communicate Anonymously. These mail programs accept incoming mail with a new address and some text for the body of the letter. They strip off the incoming header that contains the real identity of the sender and remail the content to the new address. The recipient knows it came from an Anonymous remailer, but he/she doesn't know who sent it there. In some cases, the remailer creates a new pseudonym for the outgoing mail. There are a number of ways that the Anonymous Remailers can be enhanced with features. Some of the most important ones are encryption, latency, padding, reordering, chaining Remailers, and Anonymous posters. There are several different types of Anonymous Remailers on the network and there are subtle differences between them. Each class is written by different people and they approach the details in their own way. The path between sender and recipient is hidden from the recipient by having an intermediate machine remove the return address. More sophisticated systems can try to obscure the connection to anyone who is watching the mail messages entering and leaving the remailing computer. Basic Anonymous Remailers are only as secure as the strongest link along the chain of Remailers.
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chapter ten Anonymous Remailers
Disappearing Cryptography (Second Edition)#R##N#Information Hiding: Steganography & Watermarking, 2002Co-Authors: Peter WaynerAbstract:Publisher Summary Anonymous Remailers are simple solution for people to communicate Anonymously. These mail programs accept incoming mail with a new address and some text for the body of the letter. The program strips off the incoming header that contains the real identity of the sender and remails the content to a new address. The recipient knows that it came from an Anonymous remailer, but they do not know who sent it. In some cases, the remailer creates a new pseudonym for the outgoing mail. This can be a random string like “an41234.” Then, it keeps a secret internal log file that matches the real name of the incoming mail with the random name. If the recipient wants to reply to that person, the recipient can send mail back to “an41234” in care of the Anonymous remailer who then repackages the letter and sends it. This allows people to hold a conversation over the wires without knowing each other's identity. There are many legitimate needs for services like this, but there are also many controversial ways that Anonymous Remailers can be used. From the perspective of security, more sophisticated Remailers that try to obscure traffic analysis are quite secure. There is a wide variety of Anonymous Remailers on the Internet, and the collection is growing and shrinking constantly.
Roger Dingledine - One of the best experts on this subject based on the ideXlab platform.
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Reliability
2008Co-Authors: Roger Dingledine, Michael J. Freedman, David Hopwood, David MolnarAbstract:Abstract. We describe a design for a reputation system that increases the reliability and thus efficiency of remailer services. Our reputation system uses a MIX-net in which MIXes give receipts for intermediate messages. Together with a set of witnesses, these receipts allow senders to verify the correctness of each MIX and prove misbehavior to the witnesses. 1 Introduction Anonymous Remailers are the most common method of Anonymous e-mail communication. Despite wide use of the current global remailer network, this network is generally considered unreliable. Messages are often dropped, and the newsgroup alt.privacy.anon-server contains many examples of a message being sent two or three times in the hope that one instance will reach the destination. This unreliability directly affects the number of people using the remailer network and their traffic patterns, which reduces the anonymity these networks provide
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Reputation in P2P Anonymity Systems
2003Co-Authors: Roger Dingledine, Nick Mathewson, Paul SyversonAbstract:Decentralized anonymity systems tend to be unreliable, because users must choose nodes in the network without knowing the entire state of the network. Reputation systems promise to improve reliability by predicting network state. In this paper we focus on Anonymous Remailers and Anonymous publishing, explain why the systems can benefit from reputation, and describe our experiences designing reputation systems for them while still ensuring anonymity. We find that in each example we first must redesign the underlying anonymity system to support verifiable transactions
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Mixminion: Design of a Type III Anonymous Remailer Protocol
2003Co-Authors: George Danezis, Roger Dingledine, Nick MathewsonAbstract:We present Mixminion, a message-based Anonymous remailer protocol with secure single-use reply blocks. Mix nodes cannot distinguish Mixminion forward messages from reply messages, so forward and reply messages share the same anonymity set. We add directory servers that allow users to learn public keys and performance statistics of participating Remailers, and we describe nymservers that provide long-term pseudonyms using single-use reply blocks as a primitive. Our design integrates link encryption between Remailers to provide forward anonymity. Mixminion works in a real-world Internet environment, requires little synchronization or coordination between nodes, and protects against known anonymity-breaking attacks as well as or better than other systems with similar design parameters. 1. Overview Chaum first introduced Anonymous Remailers over 20 years ago [7]. The research community has since introduce
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Mixminion: Design of a Type III Anonymous Remailer Protocol
2003Co-Authors: George Danezis, Roger Dingledine, Nick MathewsonAbstract:We present Mixminion, a message-based Anonymous remailer protocol with secure single-use reply blocks. Mix nodes cannot distinguish Mixminion forward messages from reply messages, so forward and reply messages share the same anonymity set. We add directory servers that allow users to learn public keys and performance statistics of participating Remailers, and we describe nymservers that provide long-term pseudonyms using single-use reply blocks as a primitive. Our design integrates link encryption between Remailers to provide forward anonymity. Mixminion works in a real-world Internet environment, requires little synchronization or coordination between nodes, and protects against known anonymity-breaking attacks as well as or better than other systems with similar design parameters. 1. Overview Chaum first introduced Anonymous Remailers over 20 years ago [7]. The research community has since introduced many new designs and proofs [1, 14, 16, 19, 28, 29], and discovered a variety of new attacks [3, 5, 6, 9, 23, 35]. But because many of the newer designs require considerable coordination, synchronization, bandwidth, or processing resources, deployed Remailers still use Cottrell's Mixmaster design from 1994 [8, 26]. Here we describe Mixminion, a protocol for asynchronous, loosely federated Remailers that maintains Mixmaster's flexibility while addressing the following flaws: Replies: Mixmaster does not support replies or Anonymous recipients --- people who want these functions must use the older and less secure Cypherpunk Type I remailer design [31], which is vulnerable to replay attacks. We introduce a new primitive called a singleuse reply block (SURB), which makes replies as secure as forward messages. Furthermore in Mixminion the Remailers themselves cannot disting..
George Danezis - One of the best experts on this subject based on the ideXlab platform.
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Mixminion: Design of a Type III Anonymous Remailer Protocol
2003Co-Authors: George Danezis, Roger Dingledine, Nick MathewsonAbstract:We present Mixminion, a message-based Anonymous remailer protocol with secure single-use reply blocks. Mix nodes cannot distinguish Mixminion forward messages from reply messages, so forward and reply messages share the same anonymity set. We add directory servers that allow users to learn public keys and performance statistics of participating Remailers, and we describe nymservers that provide long-term pseudonyms using single-use reply blocks as a primitive. Our design integrates link encryption between Remailers to provide forward anonymity. Mixminion works in a real-world Internet environment, requires little synchronization or coordination between nodes, and protects against known anonymity-breaking attacks as well as or better than other systems with similar design parameters. 1. Overview Chaum first introduced Anonymous Remailers over 20 years ago [7]. The research community has since introduce
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Mixminion: Design of a Type III Anonymous Remailer Protocol
2003Co-Authors: George Danezis, Roger Dingledine, Nick MathewsonAbstract:We present Mixminion, a message-based Anonymous remailer protocol with secure single-use reply blocks. Mix nodes cannot distinguish Mixminion forward messages from reply messages, so forward and reply messages share the same anonymity set. We add directory servers that allow users to learn public keys and performance statistics of participating Remailers, and we describe nymservers that provide long-term pseudonyms using single-use reply blocks as a primitive. Our design integrates link encryption between Remailers to provide forward anonymity. Mixminion works in a real-world Internet environment, requires little synchronization or coordination between nodes, and protects against known anonymity-breaking attacks as well as or better than other systems with similar design parameters. 1. Overview Chaum first introduced Anonymous Remailers over 20 years ago [7]. The research community has since introduced many new designs and proofs [1, 14, 16, 19, 28, 29], and discovered a variety of new attacks [3, 5, 6, 9, 23, 35]. But because many of the newer designs require considerable coordination, synchronization, bandwidth, or processing resources, deployed Remailers still use Cottrell's Mixmaster design from 1994 [8, 26]. Here we describe Mixminion, a protocol for asynchronous, loosely federated Remailers that maintains Mixmaster's flexibility while addressing the following flaws: Replies: Mixmaster does not support replies or Anonymous recipients --- people who want these functions must use the older and less secure Cypherpunk Type I remailer design [31], which is vulnerable to replay attacks. We introduce a new primitive called a singleuse reply block (SURB), which makes replies as secure as forward messages. Furthermore in Mixminion the Remailers themselves cannot disting..
Michael M Mostyn - One of the best experts on this subject based on the ideXlab platform.
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the need for regulating Anonymous Remailers
International Review of Law Computers & Technology, 2000Co-Authors: Michael M MostynAbstract:The internet is being used for a number of illicit purposes including: the dissemination of child pornography, cyber-stalking, on-line defamation, copyright infringement and the destruction of trade secrets. Many of these illicit activities have proliferated in recent years because of the increasing use of Anonymous Remailers. Originally intended to provide anonymity for political dissidents and to assist the discussion of sensitive matters such as abuse or the spread of sexual disease, Remailers are now widely used for less noble purposes. A remailer strips the identification marks off an e-mail and replaces it with marks of its own. By combining a chain of Remailers with the use of encryption technology, an author can now post messages to Usenet and send e-mail with almost perfect anonymity. Although the majority of Anonymous Remailers currently exist in Western democracies, the fact that any civil libertarian, commercial operator or criminal can turn their computer into a remailer raises international ...