The c-secure codes from BIBD and packing design

The c-secure code is an important tool in the anti-pirate of digital product. There are few papers on the c-secure code since it has been introduced in Crypo´95 and only several papers work for small c, i.e. c=2,3,4. The constructions of four kinds of c-secure codes have been proposed from the BIBD(balanced incomplete block design) and packing design in this paper. The codelengths of three of them are shorter than the well-known one given by Boneh and Shaw in Crypo´95 when the code number is same. It seems that this paper is the first one for any c from combinatorial designs and the new c-secure codes have shorter codelengths and simple traitor tracing algorithms.