Efficient license validation in MPML DRM architecture

Multiparty multilevel DRM architecture (MPML-DRM-A) involves multiple parties such as owner, multiple levels of distributors and consumers. The owner issues redistribution licenses to its distributors, who in turn generate and issue variations of these redistribution licenses to their sub-distributors. Also the distributors generate and issue usage licenses to the consumers to consume the contents. But, these variations of the redistribution licenses and usage licenses generated and issued by each distributor must be validated by a validation authority against the redistribution licenses that it has received. In MPML-DRM-A, there may exist multiple, different types of redistribution licenses for a content. Validation using multiple redistribution licenses may become difficult in real time. Further, storage of multiple redistribution licenses for validation presents a challenge of reducing storage space requirements. Hence, in this paper we propose a bit-vector transform based license organizing structure, and present a method to do the validation of issued licenses in the bit-vector transform domain efficiently. Experimental results show that our license organization structure helps to achieve low validation time and storage space complexity.