<p>Key encryption key data used for communication between a key management device (3) and reception devices (4_1 to 4_N) is acquired according to a tree divided into two horizontal layers (A0, A1). In this case, the LSD method is employed as the revocation method of each section (31 [0]) belonging to the horizontal layer (A0). Moreover, the CST method is employed as the revocation method of each section (31 [1]) belonging to the horizontal layer (A1).</p>
申请公布号
WO2004093380(A1)
申请公布日期
2004.10.28
申请号
WO2004JP05458
申请日期
2004.04.16
申请人
SONY CORPORATION;MIHALJEVIC, MIODRAG, J.;ABE, JOUJI