A layered approach to security helps keep your sensitive data protected by creating sequential barriers that impede potential attackers. Defense-in-Depth (DiD) is a Security Engineering strategy that involves using overlapping measures that are sometimes intentionally redundant to prevent access to information. DiD comes from a military strategy of the same name that is designed to slow down an enemy and allow time to plan a counter-attack or safe egress. When implementing DiD, it is important to consider each element independently as well as cumulatively, while leaving room to adapt to emerging threats.
Major Elements of Defense-in-Depth
There are three levels of implementation in Defense-in-Depth. Each implementation level includes a variety of specific security measures, which should all be tailored to the unique characteristics and vulnerabilities of the asset being protected, in addition to the overall risk management strategy.
Physical security directly protects information systems or facilities from access or tampering. Some examples of physical controls include security guards for restricted areas, physical Access Control Systems (ACS) and Intrusion Detection Systems (IDS), Closed Circuit Television (CCTV), and Layer 1 fiber optic defense.
These security measures protect networks and include hardware-level, software-level, and network-level defenses. There are multiple layers of cybersecurity within this category which may include encryption, firewalls, and network Intrusion Detection Systems (IDSs).
In order to implement an effective security strategy, an organization must develop operating procedures and technical policies, which should be used to train employees in safeguarding assets. Administrative controls set the organizational standard for how all elements of Defense-In-Depth are utilized and managed.
The Philosophy Behind Defense-in-Depth
Attackers aim to exploit any vulnerability they can identify, to gain access to sensitive data or secured facilities. Defense-in-Depth creates multiple barriers to access, so even if one is breached, the threat can still be identified and dealt with before the asset is compromised. Any overlap between the layers of security is deliberately designed to maximize effectiveness and reduce risk. An effective system will employ endpoint protection but it is always preferable to detect and defeat threats, using DiD security measures, before they can reach this point.
One alternate strategy is simplicity of security, which is the idea that using multiple security measures may create gaps that attackers can exploit. In order to avoid this, it is important to carefully design your security strategy – simply adding more security measures is not effective if these are not well-thought-out and implemented by an experienced team.
Evolving Security Needs
In order for Defense-in-Depth to be effective, it needs to evolve with the changing needs of your organization and with evolving threats to security. Vulnerabilities may change over time and attackers continue to develop new strategies to access sensitive information. Periodically reassessing the threats to your organization and adapting your security measures is essential for proper risk management.
PSE Can Help You Implement a Multi-Layered Security Strategy
At Predictive Solutions Engineering (PSE), we are committed to helping you protect your critical assets. We can provide a detailed threat assessment and risk management plan and offer a variety of solutions to address vulnerabilities. Our team works with government and private sector organizations to achieve Defense-in-Depth and we are constantly developing new strategies to anticipate your unique needs.