Abstract: Plagiarism of software source code is a serious problem in two distinct areas of endeavor—cheating by students at schools and intellectual property theft at corporations. A number of algorithms have been implemented to check source code files for plagiarism, each with their strengths and weaknesses. This invention detects plagiarism by comparing statements within source code of a first program to comments within source code of a second program.

Abstract: A copy protection system and method enabling storage of copy protection information separately from protected content is disclosed. One embodiment includes a mechanism for playing a recording medium, the recording medium having stored thereon a digital content file and a copy protection information file, the mechanism producing a digital content signal from the digital content file and a copy protection signal from the copy protection file; a digital to analog converter operatively connected to the mechanism for converting the digital content signal to an analog signal; a copy protection detector connected to the mechanism for detecting a copy protection trigger present in the digital content signal; and a signal modifier connected to the copy protection detector for modifying the analog signal to include the copy protection signal in response to detection of the copy protection trigger.

Abstract: In an exemplary embodiment, digital content is mastered as a combination of encrypted data and data processing operations that enable use in approved playback environments. Player devices having a processing environment compatible with the content's data processing operations are able to decrypt and play the content. Players can also provide content with basic functions, such as loading data from media, performing network communications, determining playback environment configuration, controlling decryption/playback, and/or performing cryptographic operations using the player's keys. These functions allow the content to implement and enforce its own security policies. If pirates compromise individual players or content titles, new content can be mastered with new security features that block the old attacks. A selective decryption capability can also be provided, enabling on-the-fly watermark insertion so that attacks can be traced back to a particular player.

Abstract: In an exemplary embodiment, digital content is mastered as a combination of encrypted data and data processing operations that enable use in approved playback environments. Player devices having a processing environment compatible with the content's data processing operations are able to decrypt and play the content. Players can also provide content with basic functions, such as loading data from media, performing network communications, determining playback environment configuration, controlling decryption/playback, and/or performing cryptographic operations using the player's keys. These functions allow the content to implement and enforce its own security policies. If pirates compromise individual players or content titles, new content can be mastered with new security features that block the old attacks. A selective decryption capability can also be provided, enabling on-the-fly watermark insertion so that attacks can be traced back to a particular player.

Abstract: In an exemplary embodiment, digital content is mastered as a combination of encrypted data and data processing operations that enable use in approved playback environments. Player devices having a processing environment compatible with the content's data processing operations are able to decrypt and play the content. Players can also provide content with basic functions, such as loading data from media, performing network communications, determining playback environment configuration, controlling decryption/playback, and/or performing cryptographic operations using the player's keys. These functions allow the content to implement and enforce its own security policies. If pirates compromise individual players or content titles, new content can be mastered with new security features that block the old attacks. A selective decryption capability can also be provided, enabling on-the-fly watermark insertion so that attacks can be traced back to a particular player.

Abstract: In the known color stripe process for preventing recording of video signals, the color burst present on each line of active video is modified so that any subsequent video tape recording of the video signal shows variations in the color fidelity that appear as undesirable bands or stripes of color error. This color stripe process is defeated first by determining the location of the video lines including the color stripe process, either by prior experimentation or by on-line detection. Then some or all of the lines including the modified color bursts are modified so as to render the overall video signal recordable. The modification is accomplished in a number of ways, including phase shifting the color stripe burst into the correct phase, replacing some of the color stripe bursts or a portion of particular color stripe bursts so that they are no longer effective, and mixing the color stripe burst with color stripe signals of the correct phase so as to eliminate most or all of the phase error present.

Abstract: A method for protecting data recorded on an original storage medium against unauthorized copying. The data are encoded in accordance with Standard 908 of the International Electrotechnical Commission. A portion of the encoded data is altered to introduce an error in a sub-code Q channel of the data, such that the altered data are inconsistent with Standard 908, but do not prevent playback of the data following recording thereof. The data, including the altered data, are recorded on the original storage medium, whereby an application which plays back the recorded data runs in a manner substantially unaffected by the alteration of the data, but a substantially unrecoverable error occurs in unauthorized copying of the original storage medium.

Abstract: A method for copy protection includes receiving data in a recording module representing content to be recorded on a recording medium, the data including an indication that the content is to be protected from unauthorized copying. Responsive to the indication, the recording module signals a protection module to initiate a protection protocol in synchronization with the recording module. The protection module generates control information, so as to prevent the unauthorized copying of the content that is to be protected, and conveys the control information to the recording module, in accordance with the protocol. The recording module combines the control information with the data representing the content in the recording module, for recording on the recording medium.

Abstract: A method and apparatus for distributing proprietary material employs multiple watermarks embedded in the proprietary material for enhanced copy protection. A first watermark is to be processed by programmable and non-programmable devices configured to process the first watermark for copy protection of the proprietary material. If a programmable device eliminates the first watermark so that unauthorized copies of the proprietary material can be made, then non-programmable devices configured to process a second watermark as well as the first watermark look for and process the second watermark for copy protection of the proprietary material upon their failure to detect the first watermark.