Cloud Access Security Broker (CASB): Functions, Benefits, and Structure

Before migrating to the cloud, many organizations may have cloud access security concerns. This article will delve into how cloud access security brokers (CASBs) address these concerns through their structure, operation, and function. CASBs have become an essential part of security, creating an environment where businesses can safely use the cloud while protecting their valuable data. CASBs are able to ensure security by acting as a policy enforcement center, utilizing a variety of security types, and applying them in enterprise security.

What is a Cloud Access Security Broker (CASB)?

Cloud access security brokers (CASB) act as a policy enforcement point between cloud service consumers and cloud service providers that combine and interject enterprise security policies as cloud-based resources are accessed. Essentially, they enforce the rules and regulations set by cloud service administrators.

CASBs are becoming more popular for addressing cloud service risks, enforcing security policies, and complying with regulations. CASBs can address gaps in security through SaaS, PaaS, and IaaS environments. Furthermore, a CASB allows organizations to extend their security policies from pre-existing on-premises infrastructure to the cloud—and create new cloud-specific regulations. This is essential as on-premises services migrate to the cloud and allow for maintaining visibility and safeguarding enterprises from attacks while providing safe employee access.

How CASBs Work to Ensure Cloud Access Security

A cloud security broker can use a variety of security policies to increase effectiveness, including single sign-on (SSO), authentication, authorization, device profiling, credential mapping, encryption alerting, tokenization, malware detection, and more.

CASBs provide visibility and fine-grain control over data to meet security standards. The three pillars of a CASB are:

• Discovery. CASBs use auto-discovery software to create a list of cloud services and their users.
• Classification. Once there is an understanding of the cloud usage, CASBs then use a classification method to determine what each application is, what data is used, and how it is shared.
• Remediation. After a risk assessment has been conducted on each application, the CASB uses the information to set policies for data and user access and meet security requirements automatically.

CASBs have enabled enterprises to gain visibility into the cloud and SaaS usage. As many businesses have moved their storage from on-premises to the cloud, CASBs have been able to protect the movement of data by restricting and monitoring access and sharing privileges. Additionally, CASBs work with encryption to secure data while offering additional layers of security through malware protection.

CASB Benefits and Structure

CASBs offer a variety of unique security features when compared with other enterprise application firewalls or secure web gateways. CASBs utilize the following to maximize enterprise security:

• Data loss prevention protocols 
• Cloud governance 
• Risk assessments 
• Threat prevention 
• Configuration auditing 
• Malware detection
• Data encryption and key management 
• Contextual access control 
• SSO and IAM integration 

The components that work together to create the structure of CASBs include visibility, compliance, data security, and threat protection. 

Visibility is essential across both managed and unmanaged devices. Rather than a strict “allow'' or “block” classification, cloud brokerage allows IT personnel to allow specific services and govern access to other activities. CASBs are also especially useful in helping administrators discover what cloud services are being used. They can also provide reports on cloud expenditure and find system redundancies.