The OWASP Security Principles are a set of guidelines for designing and implementing secure software systems. OWASP (Open Web Application Security Project) is a non-profit organization that aims to improve the security of web applications.

Here are the OWASP Security Principles:

1. Security by Design: Security should be considered throughout the entire software development lifecycle, from design to deployment. This principle emphasizes the importance of integrating security into every stage of the development process.

2. Default Deny: All requests and access should be denied by default, unless explicitly allowed. This principle ensures that only authorized access is granted, reducing the risk of unauthorized access.

3. Defense in Depth: Multiple layers of security controls should be implemented to protect against different types of attacks. This principle recognizes that no single security control is foolproof and that multiple layers of defense are needed to provide adequate protection.

4. Fail Securely: Systems should be designed to fail securely, meaning that if a failure occurs, the system should default to a secure state. This principle ensures that even in the event of a failure, the system remains secure. For example, when a firewall fails it should simply close all connections and block all new ones, rather than start accepting everything.

5. Least Privilege: Users and systems should only be granted the minimum privileges necessary to perform their tasks. This principle reduces the attack surface by limiting the amount of damage that can be done in the event of a breach.

6. Separation of Duties: No single person or entity should have complete control over a system or process. This principle ensures that no individual can compromise the security of the system without being detected.

7. Keep Security Simple: Security mechanisms should be simple, intuitive, and easy to use. This principle recognizes that complex security mechanisms can be difficult to implement and maintain, increasing the risk of security breaches.

8. Fix Security Issues Correctly: Security issues should be fixed correctly, rather than just applying a quick fix. This principle ensures that security vulnerabilities are properly addressed, reducing the risk of future breaches.

9. Verify Security: Security mechanisms should be regularly verified to ensure they are functioning correctly. This principle recognizes that security mechanisms can fail or be bypassed, and regular verification is necessary to ensure their effectiveness.

10. Security is a Shared Responsibility: Security is a shared responsibility among all stakeholders, including developers, users, and system administrators. This principle recognizes that security is a collective responsibility and that everyone has a role to play in maintaining the security of a system.

By following these OWASP Security Principles, developers and organizations can design and implement more secure software systems, reducing the risk of security breaches and protecting sensitive data.