What is the most effective way to ensure third-party providers comply with an organization's information security policy?

The choice of periodic auditing as the most effective way to ensure third-party providers comply with an organization's information security policy is rooted in the comprehensive and systematic approach that audits offer. Periodic audits involve a thorough evaluation of the third-party provider's adherence to the established security policies and controls over a specified duration. This process not only identifies gaps or deviations from the organization's security requirements but also ensures ongoing compliance.

Audits can encompass various aspects, such as examining documentation, assessing controls, and interviewing personnel. They are designed to provide independent verification of the security measures in place, thus fostering accountability and reinforcing the importance of adhering to the organization's policies. Additionally, the findings from audits can lead to actionable insights that help mitigate any identified risks, thereby enhancing the overall security posture.

While security awareness training, penetration testing, and service level monitoring all play significant roles in the broader scope of security management, they do not offer the same level of scrutiny or in-depth analysis that periodic audits provide. Training aims to educate staff about security practices, penetration testing is focused on identifying vulnerabilities, and service level monitoring tracks performance metrics, but none of these methods directly assess compliance with internal policies in the systematic manner that audits do.