Rotating cryptographic keys regularly is a security best practice that helps to mitigate the risk of unauthorized access to encrypted data. When keys are rotated, old keys are retired and replaced with new ones, making any compromised keys useless to an attacker. This process helps to limit the time window during which a stolen key can be used to breach data. Key rotation is a fundamental aspect of key management lifecycle best practices, which include generating new key pairs, rotating keys at set intervals, revoking access to keys, and destroying out-of-date or compromised keys.
References = The importance of key rotation is supported by various security standards and best practices, including recommendations from the National Institute of Standards and Technology (NIST)1 and the Cloud Security Alliance (CSA)23. These sources emphasize the need for periodic renewal and decommissioning of old keys as part of a comprehensive key management strategy.

Explanation
When establishing cloud governance, an organization should first test by migrating a few applications to the cloud. Cloud governance is the process of defining and implementing policies, procedures, standards, and controls to ensure the effective, efficient, secure, and compliant use of cloud services. Cloud governance requires a clear understanding of the roles, responsibilities, expectations, and objectives of both the cloud service provider and the cloud customer, as well as the alignment of the cloud strategy with the business strategy. Cloud governance also involves monitoring, measuring, and reporting on the performance, availability, security, compliance, and cost of cloud services.
Migrating a few applications to the cloud can help an organization to test and validate its cloud governance approach before scaling up to more complex or critical applications. Migrating a few applications can also help an organization to:
Identify and prioritize the business requirements, risks, and benefits of moving to the cloud.
Assess the readiness, suitability, and compatibility of the applications for the cloud.
Choose the appropriate cloud service model (such as SaaS, PaaS, or IaaS) and deployment model (such as public, private, hybrid, or multi-cloud) for each application.
Define and implement the necessary security, compliance, privacy, and data protection measures for each application.
Establish and enforce the roles and responsibilities of the cloud governance team and other stakeholders involved in the migration process.
Develop and execute a migration plan that includes testing, validation, verification, and rollback procedures for each application.
Monitor and measure the performance, availability, security, compliance, and cost of each application in the cloud.
Collect feedback and lessons learned from the migration process and use them to improve the cloud governance approach.
Migrating a few applications to the cloud can also help an organization to avoid some common pitfalls and challenges of cloud migration, such as:
Migrating legacy or incompatible applications that require significant re-engineering or refactoring to work in the cloud.
Migrating all applications at once without proper planning, testing, or governance, which can result in operational disruptions, data loss, security breaches, or compliance violations.
Migrating complex or critical applications without adequate testing or governance, which can increase the risk of failure or downtime.
Migrating applications without considering the impact on the end-users or customers, who may experience changes in functionality, performance, usability, or accessibility.
Therefore, migrating a few applications to the cloud is a recommended best practice for establishing cloud governance. It can help an organization to gain experience and confidence in using cloud services while ensuring that its cloud governance approach is effective, efficient, secure, and compliant.
References:
Migration environment planning checklist - Cloud Adoption Framework
Cloud Governance: What You Need To Know - Forbes
Cloud Governance: A Comprehensive Guide - BMC Blogs

One possible reason why the results of third-party audits and certification should be relied on when analyzing and assessing the cybersecurity risks in the cloud is to contrast the risk generated by the loss of control. When an organization moves its data and processes to the cloud, it inevitably loses some degree of control over its security and compliance posture, as it depends on the cloud service provider (CSP) to implement and maintain adequate security measures and controls1 This loss of control can increase the organization's exposure to various cybersecurity risks, such as data breaches, unauthorized access, denial of service, malware infection, etc2 To mitigate these risks, the organization needs to have a clear understanding of the security and compliance level of the CSP, as well as the shared responsibility model that defines the roles and responsibilities of both parties3 Third-party audits and certification can provide some level of assurance that the CSP meets certain standards and requirements related to security and compliance, such as ISO/IEC 27001, CSA STAR, SOC 2, etc. These audits and certification can also help the organization compare and contrast the security posture of different CSPs in the market, as well as identify any gaps or weaknesses that need to be addressed or compensated.
Therefore, relying on the results of third-party audits and certification can help the organization contrast the risk generated by the loss of control in the cloud, and make informed decisions about selecting and managing its cloud services.

The cloud service provider is responsible for the patching of the hypervisor layer in all three cloud deployment models (IaaS, PaaS, and SaaS). The hypervisor layer is the software that allows the creation and management of virtual machines on a physical server. The hypervisor layer is part of the cloud infrastructure, which is owned and operated by the cloud service provider. The cloud service provider is responsible for ensuring that the hypervisor layer is secure, reliable, and up to date with the latest patches and updates. The cloud service provider should also monitor and report on the status and performance of the hypervisor layer, as well as any issues or incidents that may affect it.
The cloud service customer is not responsible for the patching of the hypervisor layer, as they do not have access or control over the cloud infrastructure. The cloud service customer only has access and control over the cloud resources and services that they consume from the cloud service provider, such as virtual machines, storage, databases, applications, etc. The cloud service customer is responsible for ensuring that their own cloud resources and services are secure, compliant, and updated with the latest patches and updates.
The patching of the hypervisor layer is not a shared responsibility between the cloud service provider and the cloud service customer, as it is solely under the domain of the cloud service provider. The shared responsibility model in cloud computing refers to the division of security and compliance responsibilities between the cloud service provider and the cloud service customer, depending on the type of cloud deployment model. For example, in IaaS, the cloud service provider is responsible for securing the physical infrastructure, network, and hypervisor layer, while the cloud service customer is responsible for securing their own operating systems, applications, data, etc. In PaaS, the cloud service provider is responsible for securing everything up to the platform layer, while the cloud service customer is responsible for securing their own applications and data. In SaaS, the cloud service provider is responsible for securing everything up to the application layer, while the cloud service customer is responsible for securing their own data and user access.
Patching on hypervisor layer is required, as it is essential for maintaining the security, reliability, and performance of the cloud infrastructure. Patching on hypervisor layer can help prevent vulnerabilities, bugs, errors, or exploits that may compromise or affect the functionality of the virtual machines or other cloud resources and services. Patching on hypervisor layer can also help improve or enhance the features or capabilities of the hypervisor software or hardware. References :=
* Patching process - AWS Prescriptive Guidance
* What is a Hypervisor in Cloud Computing and Its Types? - Simplilearn
* In all three cloud deployment models, (IaaS, PaaS, and ... - Exam4Training
* Reference Architecture: App Layering | Citrix Tech Zone
* Hypervisor - GeeksforGeeks