Why is diversity necessary to provide better security?

What will be an ideal response?

Diversity is closely related to layering. Just as it is necessary to protect data with layers of security, so too must the layers be different (diverse), so that if a thief penetrates one layer he cannot use the same techniques to break through all other layers. For example, a thief might be able to foil the security camera in a bank by dressing in black clothes but should not be able to use the same steps to trick the motion detection system.

Using diverse layers of defense means that breaching one wireless security layer does not compromise the entire system. This can be achieved in different ways. It is possible to set a firewall to filter a specific type of traffic, such as all inbound traffic, while a second firewall on the same system filters other traffic types, such as outbound traffic. In addition, using firewalls produced by different vendors creates even greater diversity: an attacker who can get though a Brand A firewall would have more difficulty trying to break through a Brand B firewall because they are different. In wireless networks, diversity in the transitional security model involves implementing both MAC address filtering and DHCP restrictions.