Application Identifiers

In contrast, the "Application Identifiers" section contains precise file identifiers based on the file, in the form of "Uniform Resource Identifers" (URIs). These identifiers may be related to the Bitprint or other cryptographic hash of the of the file's contents, but contain no location information.

These kinds of reliable identifiers can be helpful to determine if you already have a file, to lookup additional information about files, to verify a file's contents, or perform other searching/cataloguing functions with the aid of other software.

Whether anything happens, and what happens, when using such identifiers depends on what other software you have installed.

The presence of identifiers here does not mean that the referenced file is now, or has ever been, made available to the public -- only that a Bitpedia contributor at one time reported a file with such identifiers to the encyclopedia.

Also, the presence of identifiers here does not mean that the referenced files are legal to distribute, download, or possess. Please respect all applicable laws.

Remember that all Bitpedia information is user-contributed and unverified, provided as-is, with no warranties whatsoever. Use at your own risk.

Identifier Types

MAGNET URIs are an open standard for referring to precise media by hash or other identifying characteristics. Often, one or more locally-available programs can handle a MAGNET URI.

Bitpedia's MAGNET URIs always include a strong hash identifier – SHA1 – which is part our complete Bitprint. You must have software installed which handles "magnet:..." identifiers for a link with a MAGNET URI to do anything.

If two files give the same SHA1 value, you can be highly confident that they have identical contents, because it is considered practically impossible to create or discover different files which calculate out to the same SHA1 value. [*]

Many Gnutella programs have implemented support for handling SHA1 MAGNET links. More information can be found at the MAGNET-URI Project site at SourceForge, and several of the programs listed at Bitzi-Powered Applications include support for both Bitzi lookups and MAGNET link handling.

Where possible, Bitzi MAGNET links also include the KZHASH identifier used by recent versions of Kazaa Media Desktop and Grokster. This KZHASH value is based on the MD5 hash algorithm, applied to subsections of a file via a recursive, tree process.

Kazaa or Grokster, when installed and configured to handle MAGNET links on your machine, will begin a search/download of a specific file when you click a "magnet:..." link containing a KZHASH value.

Starting in version 0.6.0, the Bitzi Bitcollider tool can calculate KZHASH identifiers at the same time it is calculating Bitzi Bitprints and extracting other intrinsic file metadata.

ED2K ( EDonkey2000, EMule, Overnet, and others)

EDonkey2000 ("ED2K"), eMule, and OverNet all use a two-level hashing scheme, based on a precursor to the "MD5" algorithm, to create their file identifiers. You must have one of these programs installed for these "ed2k:..." links to do anything. Different files are highly unlikely to have the same ED2K hash value unless a sophisticated attacker has intentionally manipulated one or both files' contents to create matching hash values. (This requires effort but is feasible for a skilled operator.)

Starting in version 0.4.0, the Bitzi Bitcollider tool can calculate ED2K identifiers at the same time it is calculating Bitzi Bitprints and extracting other intrinsic file metadata.

For More Information

• The World Wide Web Consortium on Naming and Addressing: URIs, URLs, ...
• MAGNET-URI Project site at SourceForge
• File Sharing and Bitpedia