A method for controlling the release of an as-rendered configuration of a digital work, comprising the steps of presenting said digital work as a composite of a plurality of layers comprising at least a first layer and a second layer; providing a rendering protocol interface which is adapted for defining said as-rendered configuration of the digital work by specifying a first rendering status of said first layer and a second rendering status of said second layer; providing a rendering protocol facility adapted for storing and controlling the release of said first and second rendering status of said first and second layers respectively in accordance with said as-rendered configuration; restricting unauthorized access to the rendering protocol interface, thereby preventing unauthorized modification of said as-rendered configuration; and releasing said digital work with said as-rendered configuration. The method has application in selling books, movies, software, music and other information products. A method of selling a preview version of an information product along with an option of purchase of the original version is described.

A method for controlling the release of an as-rendered configuration of a digital work, comprising the steps of presenting said digital work as a composite of a plurality of layers comprising at least a first layer and a second layer; providing a rendering protocol interface which is adapted for defining said as-rendered configuration of the digital work by specifying a first rendering status of said first layer and a second rendering status of said second layer; providing a rendering protocol facility adapted for storing and controlling the release of said first and second rendering status of said first and second layers respectively in accordance with said as-rendered configuration; restricting unauthorized access to the rendering protocol interface, thereby preventing unauthorized modification of said as-rendered configuration; and releasing said digital work with said as-rendered configuration. The method has application in selling books, movies, software, music and other information products. A method of selling a preview version of an information product along with an option of purchase of the original version is described.

A method for controlling the release of an as-rendered configuration of a digital work, comprising the steps of presenting said digital work as a composite of a plurality of layers comprising at least a first layer and a second layer; providing a rendering protocol interface which is adapted for defining said as-rendered configuration of the digital work by specifying a first rendering status of said first layer and a second rendering status of said second layer; providing a rendering protocol facility adapted for storing and controlling the release of said first and second rendering status of said first and second layers respectively in accordance with said as-rendered configuration; restricting unauthorized access to the rendering protocol interface, thereby preventing unauthorized modification of said as-rendered configuration; and releasing said digital work with said as-rendered configuration. The method has application in selling books, movies, software, music and other information products. A method of selling a preview version of an information product along with an option of purchase of the original version is described.

Pirated copies of various types of media are analyzed to detect various artifacts that may be missing from the originals. These artifacts are then used to identify and trace pirated copies for forensic studies. The artifacts may include global artifacts that are present throughout media, or could be local or special artifacts that are present only in a small portion of the media. Moreover the artifacts can be at least one of an audio event, a visual event, a visual watermark or an audio watermark.

In some embodiments, a method includes receiving, at a device, digital audio content to be converted by a digital-to-analog converter to produce analog audio content. The digital audio content has at least one audible frequency. The method also includes selecting, at the device, a first signal and a second signal to output with the analog audio content. The first signal has an inaudible carrier frequency and a bandwidth, and the second signal also has an inaudible carrier frequency and a bandwidth. A difference between the first signal and the second signal is an undesired audible signal. The method further includes outputting, from the device, the analog audio content, the first signal and the second signal, such that when the analog audio content is detected by a recording device the undesired audible signal is detected with the analog audio content.

In some embodiments, a method includes receiving, at a device, digital audio content to be converted by a digital-to-analog converter to produce analog audio content. The digital audio content has at least one audible frequency. The method also includes selecting, at the device, a first signal and a second signal to output with the analog audio content. The first signal has an inaudible carrier frequency and a bandwidth, and the second signal also has an inaudible carrier frequency and a bandwidth. A difference between the first signal and the second signal is an undesired audible signal. The method further includes outputting, from the device, the analog audio content, the first signal and the second signal, such that when the analog audio content is detected by a recording device the undesired audible signal is detected with the analog audio content.