TLDR: A security principle is a foundational guideline or rule designed to protect data, systems, and networks from threats. These principles underpin the design, implementation, and management of security measures in digital and physical environments. Key examples include confidentiality, integrity, and availability—often referred to as the CIA triad—which form the basis of secure systems and policies.
https://en.wikipedia.org/wiki/Information_security
In practice, security principles include least privilege, where users and systems are granted only the access necessary for their roles, reducing the risk of unauthorized actions. Another critical principle is defense in depth, which layers multiple security controls to create redundancy and protect against a variety of threats. Principles like non-repudiation ensure accountability, making it impossible for parties to deny their involvement in transactions or communications.
https://csrc.nist.gov/glossary/term/security_principle
Adhering to security principles is essential in areas such as software development, network administration, and data management. For example, secure coding practices incorporate principles like input validation and secure authentication to prevent vulnerabilities. In organizational settings, compliance with standards like ISO 27001 or NIST frameworks helps formalize these principles, ensuring consistent and effective security measures across systems and processes.