In information security, Defense in Depth is a collaborative use of multiple security countermeasures to protect an enterprise against targeted attacks. We can define targeted attacks, as attacks that are against the confidentiality, integrity, and availability of a system/service.
Defense in Depth is also called the layered-based approach and ideally, each layer protects against a specific type of threat. When these layers are combined together, they act as a shield that protects against most attacks.
While we are talking about layers, let's look at some layers:
- Firewalls
- Antivirus
- Intrusion prevention systems (IPS) / Intrusion detection systems (IDS)
- Virtual private networks (VPN)
- Vulnerability scanners
- Multi-Factor authentication (MFA)
- Encryption
- Hashing
- Web application firewall
- Authentication and authorization
- Demilitarized zones (DMZ...
