Comprehensive and Detailed Step by Step
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.
Reference:
C . Begin using cloud-managed keys on all new resources deployed in the cloud: While this would reduce costs, it's a broad approach that doesn't consider the sensitivity of the data. Applying cloud-managed keys to sensitive data might not be acceptable from a security standpoint.
D . Extend the key rotation period to one year so that the cloud provider can use cached keys: Extending the key rotation period weakens security. Frequent key rotation is a security best practice to limit the impact of a potential key compromise.
Why B is the Correct answer:
Risk-Based Approach: Using cloud-provider-managed keys for public data is a reasonable risk-based decision. Public data, by definition, is not confidential.
Cost Optimization: This directly addresses the CISO's concern about cost, as cloud-provider-managed keys are often free or significantly cheaper.
Security Balance: It maintains a strong security posture for sensitive data by continuing to use customer-managed keys where appropriate, while optimizing costs for less sensitive data.
CASP+ Relevance: This approach demonstrates an understanding of risk management, data classification, and cost-benefit analysis in security decision-making, all of which are important topics in CASP+.
Elaboration on Data Classification:
Data Classification Policy: Organizations should have a clear data classification policy that defines different levels of data sensitivity (e.g., public, internal, confidential, restricted).
Security Controls Based on Classification: Security controls, including encryption key management, should be applied based on the data's classification level.
Cost-Benefit Analysis: Data classification helps organizations make informed decisions about where to invest in stronger security controls and where cost optimization is acceptable.