Anonymity

For humans, anonymity is the state of one's personal identity or personally identifiable information being hidden or unknown.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Rigorous studies in cryptography define a group of possible sources called the "anonimity set". If it is not distinguishable which entity in the anonymity set has sent the message, then the source is anonymous.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Anonymity is often distinguished from pseudonymity. Purely anonymous messages have no identifying features, which makes it unclear whether or not several different messages have been sent by the same source. When continuity is useful or desired, a distinguishing characteristic (but one which does not link the source to their birth name, residence, etc.) may be chosen, such as a pseudonym, to establish which previously encountered source has sent the message. Similar techniques may be used for in-person encounters, such as wearing a unique piece of clothing, or exposing one's face without giving one's name or other personally identifiable information.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In casual conversation, many people do not distinguish between anonymity and pseudonymity, since the effect of obscuring the subject's "conventional" identity is the same.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The problem of determining whether or not the identity of a communication partner is the same as one previously encountered is the problem of authentication.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Personal identity: In philosophy, the issue of personal identity concerns the conditions under which a person at one time is the same person at another time. An analysis of personal identity provides a set of necessary and sufficient conditions for the identity of the person over time. This concept of personal identit...

Personally identifiable information: In information security and privacy, personally identifiable information or personally identifying information (PII) is any piece of information which can potentially be used to uniquely identify, contact, or locate a single person....

Pseudonymity: In cryptography, pseudonymity is the ability to prove a consistent identity without revealing oneself, instead using a pseudonym....