On the Properties of Algebraic Geometric Codes as Copy Protection Codes

Traceability schemes that are applied to broadcast encryption can prevent unauthorized parties from accessing the distributed data. In a traceability scheme, distributor broadcasts encrypted data and gives each authorized user unique key identifying word selected error-correcting code for decrypting. The following attack is possible in these schemes: groups of c malicious users join into coalitions gain illegal access by combining their keys codewords obtain pirate codeword. To this type attack, classes codes with special c-FP c-TA properties used. particular, make direct compromise scrupulous impossible it identify one attackers. We considering problem evaluating lower upper boundaries on c, within which L-construction algebraic geometric have corresponding properties. case an arbitrary curve, bound property was obtained earlier; paper, constructed. curves infinite point, bounds value both During our work, we proven auxiliary lemma proof contains explicit way build coalition pirate-identifying vector. Methods principles presented be important analyzing schemes’ robustness. Also, boundaries’ monotonicity subcodes proven.