Best Practices for Information Security Compliance by IT Service Providers

D.

To ensure compliance with an organization's information security requirements by an IT service provider, a combination of measures is usually needed. However, of the options provided, the best choice is D, requiring regular reporting from the IT service provider.

The reason why D is the best choice is that it provides ongoing oversight of the IT service provider's performance, and ensures that the organization can detect and address any potential security issues in a timely manner. By requiring regular reports, the organization can monitor the IT service provider's adherence to established security policies, procedures, and controls. Regular reporting also provides the organization with a means to measure the effectiveness of the IT service provider's security measures and to ensure that they are achieving the desired security outcomes.

Option A, defining the business recovery plan with the IT service provider, is a good measure for ensuring that the IT service provider can recover from a disaster or other unexpected event. However, it does not necessarily ensure compliance with information security requirements.

Option B, requiring external security audits of the IT service provider, can be a useful measure for verifying the IT service provider's compliance with security standards and regulations. However, audits are typically performed on a periodic basis, whereas regular reporting provides ongoing oversight.

Option C, defining information security requirements with internal IT, is an important step in establishing security requirements for the IT service provider. However, it alone does not ensure compliance with these requirements. Defining security requirements is only the first step; ongoing monitoring and reporting is needed to ensure that the IT service provider is meeting those requirements.

In summary, while a combination of measures may be needed to ensure compliance with an organization's information security requirements by an IT service provider, requiring regular reporting from the IT service provider is the best choice among the options provided.