4) Layer 4: communication security 5)
4) Layer 4: communication security 5)

The fifth layer: application security security test, anti repudiation test, security verification test, identity authentication test, recovery mechanism inspection, confidentiality test, reliability test and availability test 6) the sixth layer: operation security 7) the seventh layer: management of security personnel, training management, application system management, software management, equipment management, document management, data managementOperation management, operation management and machine room management