Abstract: A computer-based system and method is provided which use multilevel hashing for lookup of a complex nested object (such as access control list) which has a plurality of nesting levels and each level has at least one element. Method stores representatives of a complex nested object in a data structure at locations determined by recursive multilevel hashing of the complex nested object elements. When needed, a match for an inputted complex nested object is determined by applying the same recursive multilevel hashing to the inputted complex nested object, as used during the storing of the complex nested object, and performing integer comparisons with hash values of the stored complex nested object.

Abstract: A method, system and computer readable medium for the blocking of recording digital content at an end user multimedia end-user-system during the rendering of encrypted digital multimedia files. Before the process of rendering of encrypted digital multimedia can be started all rendered media stream during playback are opened to ensure that this multimedia content is not recorded. This blocks the usage of the multimedia interfaces including devices and/or ports that can be used to store un-encrypted content that has been decrypted for the purposes of playing or rendering. The method also includes an exception, which allows recording with permission from the present invention.

Abstract: A method of managing keys is provided. According to one exemplary method, digital content data encrypted with a first encrypting key is decrypted using a first decrypting key, and re-encrypted using a second encrypting key. A second decrypting key is encrypted using a third encrypting key to produce an encrypted second decrypting key. In some embodiments, an encrypted first decrypting key that was encrypted using a fourth encrypting key is received, and the encrypted first decrypting key is decrypted using a fourth decrypting key to reproduce the first decrypting key. An application for use on a computer system is also provided.