An internationalized domain name (IDN) is an Internet domain name that (potentially) contains non-ASCII characters. Such domain names could contain letters with diacritics, as required by many European languages, or characters from non-Latin scripts such as Arabic or Chinese. However, the standard for domain names does not allow such characters, and much work has gone into finding a way around this, either by changing the standard, or by agreeing on a way to convert internationalized domain names into standard ASCII domain names while preserving the stability of the domain name system.

The latter method now appears to be the one that will be adopted, a system called Internationalizing Domain Names in Applications (IDNA) having been proposed, based on the Punycode ASCII encoding of normalized (Nameprep) Unicode strings.

In IDNA, the term internationalized domain name means specifically any domain name consisting only of labels to which the IDNA ToASCII algorithm can be successfully applied.

History of IDN

Phishing

• It is possible to use IDN for phishing. See Internationalizing Domain Names in Applications.
• In February of 2005, The Shmoo Group made the issue of phishing by aid of IDN spoofing apparent. See The Shmoo Group - The state of homograph attacks.

External links

• Online Punycode/IDN Decoder/Encoder
• ICANN Internationalized Domain Names
• ISC IDN-OSS project
• IDN Language Table Registry
• The Shmoo Group: IDN