== Availability Availability is "the property of being accessible and usable on demand by an authorized entity." In other words, authorized persons should have access to permitted resources at all times. {nbsp} + === Examples that compromise availability: ** denial-of-service attacks (DOS) ** hardware failures ** fire or other natural disasters ** software or network misconfigurations {nbsp} + === Examples of methods ensuring availability ** intrusion detection systems (IDSs) ** network traffic control ** firewalls ** physical security of hardware and underlying infrastructure *** protections against fire, water, and other elements ** hardware maintenance ** redundancy