Comprehensive and Detailed Step by Step Explanation:
Understanding the Scenario: The organization is using customer-managed encryption keys in the cloud, which is more expensive than using the cloud provider's free managed keys. The CISO needs to find a way to reduce costs without significantly weakening the security posture.
Analyzing the Answer Choices:
A: Utilize an on-premises HSM to locally manage keys: While on-premises HSMs offer strong security, they introduce additional costs and complexity (procurement, maintenance, etc.). This option is unlikely to reduce costs compared to cloud-based key management.
B: Adjust the configuration for cloud provider keys on data that is classified as public: This is the most practical and cost-effective approach. Data classified as public doesn't require the same level of protection as sensitive data. Using the cloud provider's free managed keys for public data can significantly reduce costs without compromising security, as the data is intended to be publicly accessible anyway.