An Identicon is a visual representation of a

hash value A hash function is any function that can be used to map data of arbitrary size to fixed-size values. The values returned by a hash function are called ''hash values'', ''hash codes'', ''digests'', or simply ''hashes''. The values are usually u ...

, usually of an

IP address An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...

, that serves to identify a user of a computer system as a form of

avatar Avatar (, ; ), is a concept within Hinduism that in Sanskrit literally means "descent". It signifies the material appearance or incarnation of a powerful deity, goddess or spirit on Earth. The relative verb to "alight, to make one's appearanc ...

while protecting the user's privacy. The original Identicon was a 9-block graphic, and the representation has been extended to other graphic forms by third parties.

Invention

Don Park came up with the Identicon idea on January 18, 2007. In his words: A similar method had previously been described by Adrian Perrig and Dawn Song in their 1999 publication on hash visualization, which had already seen wide use such as in the random art of SSH keys.

Applications

* GitHub uses identicons to visually differentiate users who have not set their own avatar. * Wikis and blogs may generate identicons to visually identify authors based on IP addresses. This provides some protection against impersonation without requiring authentication. * Third-party software is available to generate identicons for the purposes of identifying eBay sellers. * The original Identicon idea has been expanded to include a couple of new, simple yet very effective, anti-

phishing Phishing is a type of social engineering where an attacker sends a fraudulent (e.g., spoofed, fake, or otherwise deceptive) message designed to trick a person into revealing sensitive information to the attacker or to deploy malicious softwar ...

protection schemes. One of them requires client-side support; Park is interested in talking to browser vendors regarding its incorporation. He calls this expansion "Gemini." * There is an add-on for

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and ...

called ''IdentFavIcon Quantum'' that, on websites without

favicon A favicon (; short for favorite icon), also known as a shortcut icon, website icon, tab icon, URL icon, or bookmark icon, is a file containing one or more small icons, associated with a particular website or web page. A web designer can create s ...

s, replaces them in the tab with Identicons based on the IP address of the website. * Anonymous email forwarding service IdBloc uses Identicons to help quickly distinguish between different email addresses visually

References

{{Reflist

External links

Don Park's original source code at GitHub

Mavenized project based on Don Park's original source code at GitHub

Identicons as Visual Fingerprints
by Phil Haack
PHP-Identicons

Identicon CFC - ColdFusion implementation of Identicons

Sigil

NIdenticon - .Net implementation of Identicons

Hash functions Computer icons Internet forum terminology Web 2.0 neologisms Identifiers