Patent ID: 7315866
Filing Date: 2008-01-01
Classification: G06F,Y10S

Abstract:
1. A method of protecting an electronic document, the method comprising: dividing an original document into one or more data blocks, each data block comprising one or more segments M grouping the one or more data blocks into one or more groups of blocks (GOB), each GOB comprising one or more data blocks B generating a corresponding hash value for each segment of each data block using a first incremental hash algorithm applied to the segments M generating a corresponding hash value for each data block of each GOB using a second commutative and incremental hash algorithm applied to the blocks B generating a hash tree structure based on the corresponding hash values for the segments and the data blocks for each GOB; signing the hash value of a root node of each hash tree structure; and generating auxiliary authentication data; wherein said step of generating the auxiliary authentication data comprises