Patent ID: 8122501
Filing Date: 2012-02-21
Classification: G06F,G09C,H04L

Abstract:
1. A method comprising: recovering a set of pirated digital files, each of said set of pirated digital files having inner codes and outer codes in a multilevel concatenated assignment configuration, wherein: each of said inner codes assigns segment variations to at least one of said pirated digital files, and each of said outer codes assigns said inner codes to devices in a content protection system; performing an inner code traitor tracing on one of said pirated digital files; extracting partial information regarding symbols of outer code among said outer codes from said inner code traitor tracing, wherein said extracting comprises determining a count score corresponding to a count of how many segments in each of said pirated digital files match with each of said outer code symbols; and performing an outer code tracing procedure using said partial information of said outer code symbols, wherein said performing outer code tracing comprises: creating a matrix which having m rows and N columns, where m is a number of recovered digital files and N is a set of potential pirates, wherein each entry [j,i] contains said count score for a user i and a pirated digital file j; and determining which of said set of potential pirates satisfy a predetermined minimizing constraint on said matrix.