[Retracted] HGKM: An Efficient Hybrid Group Key Management for Unmanned Autonomous Vehicles MBN in Wireless Network Environment

Table 8

The computation cost of leave activity to members.

Group key management approaches		Computation cost
		Member in immediately affected operation element	Newly chosen leader from that affected member element	Members outside the immediately affected operation element
HGKM	Situation (i): one member leaves one member element		0	1
	Situation (ii) one leadership contestant leaves		0	1
	Situation (iii) one leader leaves that group also one leadership contestant is ready		2	1
	Situation (iv) one leader leaves one group also never leadership contestant is ready		0	1
LKH		H
OFT		H

: the tallest from that key tree to operation element; h: the tallest from that group key tree.