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

Table 7

The computation cost of the leave action for the TKC.

Group key management approaches		Computation cost
HGKM	Situation(i) one member departs from one member element
	Situation(ii) one leader contestant leaves that group
	Situation(iii) one leader leaves that group also one leadership contestant is available to replace the current leader
	Situation(iv) one leader leaves that group, and no leadership contestant is available to replace the current leader.
LKH
OFT		H

: the tallest of that operation unit present in HGKM. h: highest of key tree group in OFT and LKH. : the number of leader units in HGKM.