Privacy Discussion Clause Samples

Privacy Discussion. Privacy Protection is the ability of individuals in group key management to seclude or reveal their own sensitive information selectively. As discussed in Section 2 that neither tree-based nor contributory group key managements consider privacy protection for individuals. All members share information securely, and individuals cannot manage their own sensitive information in systems. However, HGKM employs the leader constructs a VC with new key which is shared by all VC members and the leader knows group, subgroup, node and cluster keys, so the leader can decipher the information via networks and re-dispatch the information to VC members encrypted with the VC key. The comparison of proposed work (HGKM) to logical key hierarchy (LKH) is summarized in the table 4.1. The entries indicate the number of messages, cryptographic operations and keys required, and the following notations are used: − P,A,L : Passive users, Active users and Leaders, respectively. − n : the number of members in the subgroup. − m : the size of the cluster. − x / y : ‘x’ denotes the cost of the requesting users to join or leave, and ‘y’ denotes the cost of other users. − d : height of the tree, for the balanced tree, d=logαn, n is the number of members. − a : the degree of the tree. − ns : the number of subgroups. − H,D,E : one-way Hash, Decryption and Encryption functions, respectively. User Join User Leave User Join User Leave User P A P A P A P A Single Multi LKH AKC/ KDC O(d + ns ) O((a −1)d + ns ) 2(d − 1) E+ (ns −1) E a(d − 1) E + (ns −1) E (αn-1)/(α-1) User d (d-1)D/ D d − 1 d D d − 1 (logα n) + 1 HGKM AKC O(1) 0 O(3) 0 0 0 ns E 0 N/A BS O(1) 0 O(m −1+ n / m + ns ) 0 N/A N/A N/A User P N/A N/A 1D/3H 1D/1H 1D 1H 2 j+1 A 1D/1H 0 1H L 1E/1H 1E 1H From the table 4.1, we can see that our proposed scheme has advantages over the LKH in term of rekeying complexity. To an active user, it does not involve rekeying operations for joining and leaving. In other words, it does not trigger key updating events through group key server to reduce the load of systems. In addition, the every active user has own VC, it makes the sensitive information of active users more secure; no other active users can access it. Therefore, the scheme is suitable for the sensitive information sharing which needs group communication securely and efficiently.