Abstract: A system, method, and computer program product to renewably prevent traitors in a broadcast encryption system from re-using compromised keys. A license agency assigns individual receivers a set of Sequence Keys preferably at manufacture, and assigns Sequence Key Blocks (SKBs) to protected content files to be distributed. The files may be distributed on prerecorded media and typically include several file modifications. The particular modifications in a pirated version of a file can help identify which traitors contributed to its theft. SKBs assigned to new files distributed after traitors have been identified cannot be usefully processed using the compromised keys employed in previous content piracy. Innocent receivers that happen to have compromised key(s) in common with traitors can use a replacement uncompromised Sequence Key from the set to usefully decrypt content. Traitors will however step through all their Sequence Keys without reaching one that will work.

Abstract: A trusted Java virtual machine provides a method for supporting tamper-resistant applications, ensuring the integrity of an application and its secrets such as keys. The trusted Java virtual machine verifies the integrity of the Java application, prevents debugging of the Java application, and allows the Java application to securely store and retrieve secrets. The trusted Java virtual machine environment comprises a TrustedDictionary, a TrustedBundle, an optional encryption method for encrypting and decrypting byte codes, and an underlying trusted Java virtual machine. The encrypted TrustedDictionary protects data while the TrustedBundle protects programming code, allowing applications to store secret data and secure counters. The application designer can restrict TrustedBundle access to only those interfaces that the application designer explicitly exports. The open source code may optionally be encrypted.