Abstract: A Digital Rights Management (DRM) system for distribution of digital content such as audio or video uses a method to enhance security of the content from unauthorized access and use, including access by unauthorized players. The method does not necessarily require a token exchange and thereby minimizes storage demands on the server which distributes the digital content. The system generates and distributes keys for decryption of the digital content whereby the keys are unique to a specific player and user account.

Abstract: Computers and other electronic devices typically include a timing operation such as a clock in an operating system. It is anticipated that hackers may tamper with this clock. This tampering might be especially advantage in the context of systems which provide for rental of audio and video content, such as movies. Tampering with the system clock on the playing device would allow an extension of the rental period to the detriment of the provider of the rental content. Hence the present method is directed to detecting clock modifications both in terms of time shifting and clock rate tampering. This detection is done using digital signal processing.

Abstract: Method and apparatus for ensuring randomness of pseudo-random numbers generated by a conventional computer operating system or electronic device. Typically pseudo-random number generators used in computer operating systems or electronic devices may be penetrated by a hacker (pirate), who penetrates a cryptographic or other supposedly secure process using the random numbers by tampering with the input random numbers, thus making them nonrandom. The present method and apparatus are intended to verify such random numbers to make sure that they are indeed random enough, by applying suitable random tests. Only if the values pass the test are they passed on for use in the cryptographic or other process. If they fail the test, a new set of random numbers is requested from the pseudo-random number generator. These are again tested. Further a diversity function may be applied to the random numbers even if they have passed the random number test in order to improve their randomness.

Abstract: An integrity verification process and associated apparatus to detect tampering or other alterations to computer code (software) or other computer files, and especially useful to detect tampering with code by hackers who might try to plant their own malicious code in the software. To make the verification process more robust versus hackers, each e.g., object code file to be protected is first selected using some sort of rule, then partitioned into variable length blocks or portions, the lengths varying in an unpredictable manner. Each portion has its checksum or hash value computed. An accompanying verification file is created which includes a vector for each portion including the portion's start address in memory, length, and the computed checksum or hash value.