US 5,943,422 · Granted 1999-08-24

The Invisible Watermark Patent That Locked Down Digital Rights

Imagine embedding a secret message directly into a song or video that's impossible to see or hear, but devices can read it to enforce copyright rules. This patent describes how to hide digital instructions inside media files so they survive copying, streaming, and format changes—keeping control of who can access what.

Curated and verified by the IsItPatented Editorial team

The plain-English version

What it protects

The claim covers a method for embedding rights management control signals invisibly within digital or analog information signals using steganographic encoding. What's protected here is the specific technique of hiding low data-rate control information within high-bandwidth portions of a content signal, allowing the embedded instructions to survive format conversions and transformations between analog and digital states, and be recoverable by an electronic appliance without visibly or audibly corrupting the original content.

Why it matters

This patent addresses a core problem of the digital age: how to enforce copyright and licensing rules on content that travels over open networks and gets copied endlessly. By embedding invisible control data directly into media files themselves, rather than relying on external servers or containers, the patent enables what Intertrust called a 'Virtual Distribution Environment'—essentially a way to carry permissions with the content everywhere it goes, making it harder for unauthorized copying or redistribution to strip away licensing information.

Real-world use

When you stream a movie or download music from a licensed service, invisible watermarks embedded in those files tell your device what you're allowed to do—whether you can skip forward, download offline, or share it with others.

Original USPTO abstract

Electronic steganographic techniques can be used to encode a rights management control signal onto an information signal carried over an insecure communications channel. Steganographic techniques ensure that the digital control information is substantially invisibly and substantially indelibly carried by the information signal. These techniques can provide end-to-end rights management protection of an information signal irrespective of transformations between analog and digital. An electronic appliance can recover the control information and use it for electronic rights management to provide compatibility with a Virtual Distribution Environment. In one example, the system encodes low data rate pointers within high bandwidth time periods of the content signal to improve overall control information read/seek times.

Patent details

Publication number: US 5,943,422
Filing date: 1996-08-12
Grant date: 1999-08-24
Assignee: Intertrust Technologies Corp.
Inventor(s): VAN WIE; DAVID M., WEBER; ROBERT P.
CPC class: G06F21/10

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