Pseudonymity is a word derived from pseudonym, meaning 'false name', and describes a state of disguised identity resulting from the use of a pseudonym (also called nym). The pseudonym identifies a holder, that is, one or more human beings who possess but do not disclose their true names (that is, legal identities).^[1] For example, all of the Federalist Papers were signed by Publius, a pseudonym representing the trio of James Madison, Alexander Hamilton, and John Jay. As this example suggests, most pseudonym holders use pseudonyms because they wish to remain anonymous. But anonymity is difficult to achieve, and is often fraught with legal issues.^[2] True anonymity requires unlinkability, such that an attacker's examination of the pseudonym holder's message provides no new information about the holder's true name.^[3]In computer networks, pseudonyms possess varying degrees of anonymity,^[4] ranging from highly linkable public pseudonyms (the link between the pseudonym and a human being is publicly known or easy to discover), potentially linkable non-public pseudonyms (the link is known to system operators but is not publicly disclosed), and unlinkable pseudonyms (the link is not known to system operators and cannot be determined).^[5] A true anonymous remailer enables Internet users to establish unlinkable pseudonyms; those that employ non-public pseudonyms (such as the now-defunct Penet remailer) are called pseudonymous remailers. A pseudonym (Greek: , pseudo + -onym: false name) is an artificial, fictitious name, also known as an alias, used by an individual as an alternative to a persons legal name. ... A nym server (short for pseudonym server) is a server that provides an untraceable e-mail address, such that neither the nym server operator nor the operators of the remailers involved can discover which nym corresponds to which real identity. ... It has been suggested that this article or section be merged with Anthroponym. ... An advertisement for The Federalist The Federalist Papers are a series of 85 articles arguing for the ratification of the United States Constitution. ... James Madison (March 16, 1751 – June 28, 1836), an American politician and fourth President of the United States of America (1809–1817), was one of the most influential Founders of the United States. ... Alexander Hamilton (January 11, 1755 or 1757–July 12, 1804) was an Army officer, lawyer, Founding Father, American politician, leading statesman, financier and political theorist. ... John Jay (December 12, 1745 – May 17, 1829) was an American politician, statesman, revolutionary, diplomat, and jurist. ... Look up anonymous in Wiktionary, the free dictionary. ... This article does not cite any references or sources. ... This article does not cite any references or sources. ... An anonymous remailer is a server computer which receives messages with embedded instructions on where to send them next, and which forwards them without revealing where they originally came from. ... The Penet remailer (anon. ... A pseudonymous remailer or nym server, as opposed to an anonymous remailer, is an Internet software program designed to allow people to write anonymous messages on Usenet newsgroups and send anonymous email under a pseudonym. ...

The continuum of unlinkability can be seen, in part, on Wikipedia. Some registered users make no attempt to disguise their real identities (for example, by placing their real name on their user page). The pseudonym of unregistered users is their IP address, which can, in many cases, easily be linked to them. Other registered users prefer to remain anonymous, and do not disclose identifying information. However, Wikipedia's server logs may enable system administrators to determine the IP address, and perhaps the true name, of a registered user (see Wikipedia:Privacy Policy for a list of the conditions under which such a linkage would be attempted); this is not done unless there is a compelling reason (for example, vandalism or a law enforcement subpoena). Wikipedia (IPA: , or ( ) is a multilingual, web-based, free content encyclopedia project, operated by the Wikimedia Foundation, a non-profit organization. ... This article or section does not cite any references or sources. ...

It is possible, in theory, to create an unlinkable Wikipedia pseudonym by using an Open proxy, a Web server that disguises the user's IP address. However, most open proxy addresses are blocked indefinitely due to the their frequent use by vandals (see Wikipedia:Blocking_policy). Even if it were possible to establish an unlinkable pseudonym on Wikipedia, there would be little point in doing so. Contributing to Wikipedia establishes a public record of a user's activity. Because a user's interest areas, writing style, and argumentative positions may establish an identifiable pattern,^[6] unlinkability could be assured only by making random, pointless edits throughout the site (which would, of course, amount to vandalism). An open proxy is a proxy server which is accessible by any Internet user. ... This article or section does not cite any references or sources. ...

System operators (sysops) at sites offering pseudonymity, such as Wikipedia, are not likely to build unlinkability into their systems. If they did, they would be unable to obtain information about abusive users quickly enough to stop vandalism and other undesirable behaviors. Law enforcement personnel, fearing an avalanche of illegal behavior are equally unenthusiastic.^[7] Still, some users and privacy activists believe that Internet users deserve stronger pseudonymity so that they can protect themselves against identity theft, illegal government surveillance, stalking, and other unwelcome consequences of Internet use (including unintentional disclosures of their personal information, as discussed in the next section). Their views are supported by laws in some nations (such as Canada) that guarantee citizens a right to speak using a pseudonym. (This right does not, however, give citizens the right to demand publication of pseudonymous speech on equipment they do not own.) Debate about unlinkability is certain to remain heated. A SysOp is short for system operator, and is a commonly used term for the administrator of a bulletin board system (BBS) or special-interest area of an online service or, historically, the operators of any computer system, especially a mainframe computer. ...

Pseudonymity and confidentiality

Most Web sites that offer pseudonymity retain information about users. They should protect their users from unwanted disclosures of personal information; in other words, they should assure confidentiality (the information is available only to those authorized to have access). But Web sites are notoriously susceptible to unauthorized intrusions into their non-public database systems. For example, in 2000, a Welsh teenager obtained information about more than 26,000 credit card accounts, including that of Bill Gates.^[8] In 2003, VISA and MasterCard announced that intruders obtained information about 5.6 million credit cards.^[9] Sites that offer pseudonymity are also vulnerable to confidentiality breaches. In a study of a Web dating service and a pseudonymous remailer, Cambridge University researchers discovered that the systems used by these Web sites to protect user data could be easily compromised, even if the pseudonymous channel is protected by strong encryption. Typically, the protected pseudonymous channel exists within a broader framework in which multiple vulnerabilities exist.^[10] Pseudonym users should be in mind that, given the current state of Web security engineering, their true names may be revealed at any time. Confidentiality has been defined by the International Organization for Standardization (ISO) as ensuring that information is accessible only to those authorized to have access and is one of the cornerstones of Information security. ... A pseudonymous remailer or nym server, as opposed to an anonymous remailer, is an Internet software program designed to allow people to write anonymous messages on Usenet newsgroups and send anonymous email under a pseudonym. ... “Cipher” redirects here. ...

Pseudonymity and online reputations

Pseudonymity is an important component of the reputation systems found in online auction services (such as eBay), discussion sites (such as Slashdot), and collaborative knowledge development sites (such as Wikipedia). A pseudonymous user who has acquired a favorable reputation gains the trust of other reputable users. When users believe that they will be rewarded by acquiring a favorable reputation, they are more likely to behave in accordance with the site's policies.^[11] Look up reputation in Wiktionary, the free dictionary. ... eBay headquarters in San Jose eBay North First Street satellite office campus (home to PayPal) eBay Inc. ... This section needs additional references or sources to facilitate its verification. ... Wikipedia (IPA: , or ( ) is a multilingual, web-based, free content encyclopedia project, operated by the Wikimedia Foundation, a non-profit organization. ...

If users can obtain new pseudonymous identities freely or at very low cost, reputation-based systems are vulnerable to whitewashing attacks,^[12] (also called serial pseudonymity) in which abusive users continuously discard their old identities and acquire new ones in order to escape the consequences of their behavior: "On the Internet, nobody knows that yesterday you were a dog, and therefore should be in the doghouse today."^[13] Banned Wikipedia users who return with new identities are called sock puppets. A sock puppet, after which internet sock puppets are named. ...

The social cost of cheaply discarded pseudonyms is that experienced users lose confidence in new users,^[14] and may subject new users to abuse until they establish a good reputation.^[15] System operators may need to remind experienced users that most newcomers are well-intentioned (see, for example, Wikipedia's policy about biting newcomers). Concerns have also been expressed about sock puppets exhausting the supply of easily remembered usernames. Proposals have been made to raise the costs of obtaining new identities (for example, by charging a small fee or requiring e-mail confirmation). Others point out that Wikipedia's success is attributable in large measure to its nearly non-existent initial participation costs.

See also

• Pseudonymization
• Anonymity
• Anonymous remailer
• Cipherspace
• Confidentiality
• Digital signature
• Data haven
• Friend-to-friend
• Onion routing
• Nym server
• Penet.fi
• Pseudonym
• Pseudonymous remailer
• Public key encryption

Pseudonymization is a procedure by which all person-related data within a data record is replaced by one artificial identifier (like a hash value) that maps cone-to-one to the person. ... This article does not cite any references or sources. ... An anonymous remailer is a server computer which receives messages with embedded instructions on where to send them next, and which forwards them without revealing where they originally came from. ... Cipherspace (also spelled cypherspace) is the encrypted (and often pseudonymous or fully anonymous) equivalent to cyberspace. ... Confidentiality has been defined by the International Organization for Standardization (ISO) as ensuring that information is accessible only to those authorized to have access and is one of the cornerstones of Information security. ... In cryptography, a digital signature or digital signature scheme is a type of asymmetric cryptography used to simulate the security properties of a signature in digital, rather than written, form. ... A Data Haven is a place where data is supposed to be secure at all times. ... It has been suggested that Friend-to-friend with third party storage be merged into this article or section. ... Onion routing is a technique for pseudonymous (or anonymous) communication over a computer network, developed by David Goldschlag, Michael Reed, and Paul Syverson. ... A nym server (short for pseudonym server) is a server that provides an untraceable e-mail address, such that neither the nym server operator nor the operators of the remailers involved can discover which nym corresponds to which real identity. ... The Penet remailer (anon. ... A pseudonym (Greek: , pseudo + -onym: false name) is an artificial, fictitious name, also known as an alias, used by an individual as an alternative to a persons legal name. ... A pseudonymous remailer or nym server, as opposed to an anonymous remailer, is an Internet software program designed to allow people to write anonymous messages on Usenet newsgroups and send anonymous email under a pseudonym. ... PKC, see PKC (disambiguation) Public-key cryptography is a form of modern cryptography which allows users to communicate securely without previously agreeing on a shared secret key. ...

References

1. ^ May, Timothy C. (1991). The Crypto Anarchist Manifesto .
2. ^ du Pont, George F. (2001) The Criminalization of True Anonymity in Cyberspace 7 Mich. Telecomm. Tech. L. Rev.
3. ^ Post, David G. (1996). Pooling Intellectual Capital: Thoughts on Anonymity, Pseudoanonymity, and Limited Liability in Cyberspace. University of Chicago Legal Forum.
4. ^ Froomkin, A. Michael (1995). "Anonymity and Its Enemies (Article 4)". Journal of Online Law.
5. ^ Pfitzmann, A., and M. Köhntopp (2000). "Anonymity, Unobservability, and Pseudonymity: A Proposal for Terminology". In H. Federrath (ed.), Anonymity (Berlin: Springer-Verlag), pp. 1-9.
6. ^ Rao, J.R., and P. Rohatgi (2000). "Can Pseudonyms Really Guarantee Privacy?" Proceedings of the 9th USENIX Security Symposium (Denver, Colorado, Aug. 14-17, 2000).
7. ^ Clarke, Roger (1998). "Technological Aspects of Internet Crime Prevention." Paper presented at the Australian Institute for Criminology's Conference on Internet Crime (February 16-17, 1998).
8. ^ Reuters News Service (2000). "Report: Hackers Had Gates' Credit Card Data" (March 26, 2000).
9. ^ Katayama, F. (2003) "Hacker accesses 5.6 Million Credit Cards" CNN.com: Technology (February 18, 2003).
10. ^ Clayton, R., G. Danezis, and M. Kuhn (2001). "Real World Patterns of Failure in Anonymity Systems." Lecture Notes in Computer Science 2137:230-244.
11. ^ Kollock, P. (1999). "The Production of Trust in Online Markets." In E.J. Lawler, M. Macy, S. Thyne, and H.A. Walker (eds.), Advances in Group Processes (Greenwich, CT: JAI Press).
12. ^ Feldman, M., S. Papadimitriou, and J. Chuang (2004). "Free-Riding and Whitewashing in Peer-to-Peer Systems." Paper presented at SIGCOMM '04 Workship (Portland, Oregon, Aug. 30-Sept. 3, 2004).
13. ^ Friedman, E. and P. Resnick (2001). "The Social Cost of Cheap Pseudonyms." Journal of Economics and Management Strategy 10(2): 173-199.
14. ^ Johnson, D.G. and K. Miller (1998). "Anonymity, Pseudonymity, and Inescapable Identity on the Net." ACM SIGCAS Computers and Society 28(2): 37-38.
15. ^ Friedman and Resnick, op. cit.

Tim May was an engineer and chief scientist at Intel at an early and crucial point in that companys history. ...

External links

• Anonymity Bibliography Excellent bibliography on anonymity and pseudonymity. Includes hyperlinks.
• Anonymity Network Describes an architecture for anonymous Web browsing.
• Electronic Frontier Foundation (EFF) Anonymity/Pseudonymity Archive