The Official (ISC)2 CCSP CBK Reference. Leslie Fife

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СКАЧАТЬ the data and processes as these remain available anywhere network connectivity exists.

      Major CSPs use multiple regions and redundancy to increase the ability of a recovery. Many organizations plan a resilient strategy that includes internal resources and the capabilities of the cloud.

      Performance

      Performance is measured through an SLA. Performance of a cloud service is generally quite high as major CSPs build redundancy into their systems. The major performance concerns are network availability and bandwidth. A network is a hard requirement of a cloud service, and if the network is down, the service is unavailable. In addition, if you are in an area of limited bandwidth, performance will be impacted.

      Governance

      Cloud governance uses the same mechanisms as governance of your on-premises IT solutions. This includes policies, procedures, and controls. Controls include encryption, access control lists (ACLs), and identity and access management. As many organizations have cloud services from multiple vendors, a cloud governance framework and application can make the maintenance and automation of cloud governance manageable. This may be another cloud solution.

A variety of governance solutions, some cloud based, exist to support this need. Without governance, cloud solutions can easily grow beyond what can be easily managed. For example, a company may want to govern the number of CSP accounts, the number of server instances, the amount of storage utilized, the size of databases, and other storage tools. Each of these add to the cost of cloud computing. A tool that tracks usage and associated costs will help an organization use the cloud efficiently and keep its use under budget.

      Maintenance and Versioning

      Maintenance and versioning in a cloud environment have some advantages and disadvantages. Each party is responsible for the maintenance and versioning of their portion of the cloud stack. In a SaaS solution, the maintenance and versioning of all parts is the responsibility of the CSP, from the hardware to the SaaS solution. In a PaaS solution, the customer is responsible for the maintenance and versioning of the applications they acquire and develop. The platform and tools provided by the platforms, as well as the underlying infrastructure, are the responsibility of the CSP. In an IaaS solution, the CSP is responsible for maintenance and versioning of hardware, network and storage, and the virtualization software. The remainder of the maintenance and versioning is the responsibility of the customer.

      What this means in practical terms is that updates and patches in a SaaS or PaaS environment may occur without the knowledge of the customer. If properly tested before being deployed, it will also be unnoticed by the customer. There remains the potential for something to break when an update or patch occurs, as it is impossible to test every possible variation that may exist in the cloud environment of the customers. This is true in a traditional on-premise environment as well. In an IaaS environment, the customer has much more control over patch and update testing and deployment.

      On the positive side, there will not be the endpoints that exist in every organization that never get updated and have older, insecure versions of potentially unlicensed software. When connecting to the cloud service, the customer will always be using the newest, most secure version of the solution in a SaaS solution.

      In a PaaS or IaaS, the customer is responsible for some of the maintenance and versioning. However, each customer that connects to the PaaS and IaaS environment will be accessing the most current version provided. The maintenance and versioning are simplified by restricting the maintenance and versioning to the cloud environment. It is not necessary to update each endpoint running a particular piece of software. Everyone connecting to the cloud is running the same version, even if it is old and has not been updated.

      Service Levels and Service Level Agreements

      Contractually, an SLA specifies the required performance parameters of a solution. This negotiation will impact the price, as more stringent requirements can be more expensive. For example, if you need 24-hour support, this will be less expensive than 4-hour support.

      Some CSPs will provide a predefined set of SLAs, and customers choose the level of service they need. The customer can be an individual or an organization. For the customer contracting with a CSP, this is a straightforward approach. The CSP publishes their performance options and the price of each, and the customer selects the one that best suits their needs and resources.

      In other cases, a customer specifies their requirements, and the CSP will provide the price. If the CSP cannot deliver services at the level specified or if the price is more than the customer is willing to pay, the negotiation continues. Once agreed upon, the SLA becomes part of the contract. This is generally true only for large customers. The cost of negotiating and customizing an SLA and the associated environment is not generally cost effective for smaller contracts and individuals.

      Auditability

      A cloud solution needs to be auditable. This is an independent examination of the cloud services controls, with the expression of an opinion on their function with respect to their purpose. Are the controls properly implemented? Are the controls functioning and achieving their goal? These are the questions of an auditor.

      A CSP will rarely allow a customer to perform on audit on their controls. Instead, independent third parties will perform assessments that are provided to the customer. Some assessments require a nondisclosure agreement (NDA), and others are publicly available. These include SOC reports, vulnerability scans, and penetration tests.

      Regulatory

      Proper oversight and auditing of a CSP makes regulatory compliance more manageable. A regulatory environment is one where a principle or rule controls or manages an organization. Governance of the regulatory environment is the implementation of policies, procedures, and controls that assist an organization in meeting regulatory requirements.

      One form of regulations are those governmental requirements that have the force of law. The Health Insurance Portability and Accountability Act (HIPAA), Gramm-Leach-Bliley Act (GLBA), Sarbanes-Oxley Act (SOX) in the United States, and GDPR in the European Union are examples of laws that are implemented through regulations and have the force of law. If any of these apply to an organization, governance will put a framework in place to ensure compliance with these regulations.

Another form of regulations is those put in place through contractual requirements. An SLA takes the form of a contractual obligation as do the rules associated with credit and debit cards through the Payment Card Industry Data Security Standard (PCI DSS). Enforcement of contractual rules can be through the civil courts governing contracts. Governance must again put in place the framework to ensure compliance.

      A third form of regulations is found through standards bodies like International Organization for Standardization (ISO) and NIST as well as nongovernmental groups such as the Cloud Security Alliance and the Center for Internet Security. These organizations make recommendations and provide best practices in the governance of security and risk. These support improved security and risk management. While this form of regulation does not usually have the force of law, an organization or industry may voluntarily choose to be regulated by a specific set of guidelines. For example, U.S. federal agencies are required to follow NIST requirements. If an organization or industry chooses to follow a set of guidelines under ISO, NIST, or other group, they must put the governance framework in place to ensure compliance. While often voluntary, once an organization chooses to follow these guidelines, СКАЧАТЬ