[Retracted] Hierarchical Network Security Measurement and Optimal Proactive Defense in Cloud Computing Environments

Table 1

Risk rating matrix.

Risk impact	Risk probability	Frequent	Often	Rare	Very rare
Very serious	Low	Low	Medium	High	Medium
Serious	High	Medium	Low	High	Low
Moderate	Medium	Low	High	Medium	High
Low	Low	Medium	High	Low	High
Very low	Medium	High	Medium	Medium	Medium