XrML

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eXtensible rights Markup Language (XrML)
File extension : .drm
Developed by: Xerox PARC
Current version: 2 (as of November 2001)
Type: Markup language
Container for: DRM
Extended by: XML
Expanded to: MPEG-21

The eXtensible rights Markup Language (XrML) is a universal language for the secure description and management of rights based on the open XML standard.

These rights can be linked to any objects and define the usage rights very granularly at user and group level. The defined rights are usually summarized as a so-called rights object (RO) and can be transferred as part of the license in the context of Digital Rights Management (DRM).

XrML emerged from research at Xerox PARC (Palo Alto Research Center). Version 2 of the XrML specification has been available since November 2001 and is used by several bodies to define the DRM implementation in their own XML languages ​​(e.g. OASIS , Open eBook Forum , MPEG-21 ).

history

Xerox PARC and DPRL

Mark Stefik, a researcher at Xerox PARC , is known to be the originator of the concepts that became the XrML language. Stefik did research on trusted systems for secure digital commerce, part of which was language to express the rights the system would allow users to exercise on digital resources.

The first version of the expression language that became XrML was developed at Xerox PARC and called Digital Property Rights Language (DPRL). DPRL appears in a patent filed by Xerox in November 1994 (and granted in February 1998 ) entitled: "System for controlling the distribution and use of digital works with usage rights attached, the usage rights being defined by usage rights grammar" (US Patent 5,715 .403 issued to Xerox Corporation).

Between 1994 and 1998, Xerox formed its Rights Management Group to continue the work illustrated in the patent. In November 1998, Xerox released the first XML version of the Digital Property Rights Language (DPRL), called Version 2.0. Prior to that time, DPRL was written in the LISP programming language.

From the documentation for DPRL 2.0 it is clear that DPRL was designed for the interaction from machine to machine, whereby the rights are expressed in the form of machine-processable functions. It also makes it clear that when interpreting a DPRL-based statement of rights, only those rights that are explicitly granted can actually be implemented. All areas in which a rights specification is silent must be interpreted as rights that have not been granted and must therefore be denied by the software that enforces the rights.

XrML 1.0

In 1999, version 2 of DPRL was licensed to a Microsoft and Xerox newly founded company called ContentGuard, which DPRL developed into the eXtensible rights Markup Language (XrML). Version 1 of XrML was released in 2001 .

XrML 1.0 was a further development of DPRL. It expanded much of DPRL's administrative structure by adding unique identifiers, private and public keys, and other mechanisms to identify and verify the authenticity of the publisher and user of the resource. It also added certification for hardware and software that should be part of the trusted environment. The list of rights remained the same, although the definitions of individual rights changed somewhat. In particular, XrML 1.0 made a clear distinction between rights that created a new resource and those that modified an existing resource.

XrML 2.0

Version 2.0 of XrML was a radical departure from everything that came before it. While DPRL and XrML 1.0 contained a specific language for machine-usable rights ("copy", "transfer", "save", "install" etc.), version 2.0 was an abstract rights language with only a few core elements. The core elements of XrML 2.0 are those that are required to establish trust between systems for transactions to take place. This includes the issuer of the license, the other parties to the license, and the ability to include resources and rights, digital signatures, etc. This version is not specific to any medium or type of resource and has been generalized to control rights to digital resources, services, or other digital entities.

Web links

Individual evidence

  1. ↑ a b What is XrML (Extensible Rights Markup Language)? - Definition from WhatIs.com. Retrieved May 5, 2020 .
  2. ↑ ContentGuard Releases XrML 2.0. In: The Gilbane Advisor. November 26, 2001, Retrieved May 5, 2020 (American English).