The Cloud Access Security Broker (CASB) technology is becoming an essential security element of the Secure Access Service Edge (SASE) model. This technology pairing has conveniently arrived at a time of rapid change in the overall work environment, data location, and its security.

Organisations who have already adopted SD-WAN soon realised that an additional security layer is essential as cloud usage grows. SASE and CASB allow providers to mitigate cloud service risks, enforce security policies, and ensure compliance throughout their network.

A comprehensive CASB service secures traffic across complex networks that would be otherwise impossible with SD-WAN and SASE alone. SASE platforms with CASB are better equipped to mitigate threats from weak cloud security.

What Is CASB?

Cloud Access Security Broker (CASB) is a centralised cloud-based security policy enforcement point positioned between cloud service users and cloud service providers. Acting as a trusted security intermediary, CASB secures cloud-based resources by applying enterprise security policies.

The CASB security model enables organisations to manage and protect data and services located in the cloud. A reliable CASB solution fulfils the security requirements for both Software As A Service (SaaS) applications and the overall cloud infrastructure.

Why Do You Need CASB?

For any organisation that uses cloud services, SaaS, or remote storage, CASB is an ideal cybersecurity solution. The right CASB strategy enables you to add select security controls that protect data as it traverses between users (remote or on-prem) and cloud-based services.

With so many applications and services migrating to the cloud, the need to maintain visibility and control of cloud environments is crucial. CASB produces security between network and cloud, so employees can safely access these remote services without introducing additional risk.

How Does CASB Work?

The function of CASB is to provide visibility and control over data and threats in the cloud. This control offers layers of protection through features such as malware prevention and data encryption. It also enables your security team to comply with enterprise security requirements using a 3-step approach.

Step #1 – Discovery

CASB employs an auto-discovery feature to compile a list of cloud services and applications. Simultaneously it identifies individuals who are using those cloud-based services.

Step #2 – Classification

Once CASB identifies the full extent of cloud usage, it determines the risk level associated with each cloud-based application discovered. The type of application, the data’s sensitivity, and how it is shared are all classified.

Step #3 – Remediation

After each application’s risk is identified, CASB uses this information to set data and user access policies that meet the organisation’s security requirements. From there, the system can automatically alert and/or take action whenever a violation occurs.

The 4 Pillars Of CASB

8 Benefits of CASB

Any CASB technology article worthy of your time will discuss the four pillars of CASB. Here is a complete breakdown.

1. Visibility

Large businesses have high volumes of employees who access multiple applications across multiple cloud environments. When cloud usage moves beyond the IT department’s view, enterprise data governance, and the enforcement of security policies and compliance becomes an issue. 

To protect users, data, and intellectual property, CASB gives IT comprehensive visibility into cloud application usage, including user information like device and location information. 

Cloud discovery analysis creates a risk assessment for each cloud service in use, allowing enterprise security personnel to decide whether to permit access or block the app. 

This information helps shape more granular controls like granting varying cloud access levels for data and apps based on an employee’s job, device, and location.

2. Compliance

Even when businesses outsource their systems and data storage to the cloud, they must still comply with the regulations that govern enterprise data privacy and safety. CASB protects data stored on the cloud using security policies that are enforced cloud-wide.

CASB helps maintain compliance within the cloud by addressing a variety of compliance regulations. Such regulations can include HIPAA or regulatory requirements like ISO 27001, PCI DSS, and others. A CASB solution can determine the highest risk areas in terms of compliance and provide the security team with solid direction.

3. Data Security

By design, on-premises Data Loss Prevention (DLP) solutions safeguard data, but that ability does not extend to cloud services. CASB can monitor sensitive content as it travels to, from, and through the cloud. 

To minimise enterprise data leaks, CASB deploys security features such as:

  • Data loss prevention
  • Access and collaboration control
  • Information rights management
  • Tokenisation
  • Encryption

One of the most popular CASB features is monitoring access to data stored on the cloud. It provides access control across parameters like location, IP address, browser, operating system, and device. 

The security team can customise access. For instance, you can block a user from accessing cloud services like G Suite outside the office or add even more granular control by restricting access to cloud services only through authorised devices. 

Alternately, you could allow a user to access apps like G Suite and Salesforce from the office but only allow G Suite access from the user’s home.

4. Threat Protection

CASB alerts security teams of the threats it detects based on user behaviour. Whether through employee negligence or a third party’s malicious intent, users can leak or steal sensitive data from cloud services. 

To pinpoint such anomalous user behaviour, the system will compile a comprehensive view of typical usage patterns and use it as a basis for comparison.

CASB can detect and then remediate threats when someone attempts to steal data or improperly gain access using several methods:

  • Threat intelligence
  • Adaptive access control
  • Static and dynamic malware analysis

8 Benefits of CASB

Many CASB security features are unique compared with those from other security controls such as enterprise and web application firewalls and secure web gateways. CASB security features can include any of the following:

1. Data Loss Prevention (DLP)

DLP tools prevent enterprise data leaks due to unauthorised sharing on the cloud.

2. Contextual Access Control

Contextual access control is a firewall feature that filters Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) packets according to application layer information.

3. Threat Protection

Without CASB technology, it can be a challenge to guard against hackers’ malicious intent or authorised users’ negligence.

4. Malware Detection

In addition to monitoring authorised and unauthorised user access, CASB also has built-in malware detection protocols to find and neutralise those threats.

5. Risk Assessment

CASB provides risk assessment reports for countless cloud services so that security teams don’t have to carry out checks manually for every service.

6. Collaboration & Data Sharing Control

A CASB-fortified network allows employees to collaborate, share, and communicate all in one, secure platform.

7. Configuration Audit

CASB monitors and catalogues users accessing cloud apps from both managed and unmanaged endpoints. It audits in real-time and automatically establishes and enforces policies to protect against misuse and malicious acts on the network.

8.Data Encryption

CASB can integrate with your organisation’s existing key management solution or provide a cloud-based key management solution. Either way, the keys that encrypt your data exist within your CASB domain.

How Is CASB Deployed?

How Is CASB Deployed?

One benefit of CASB is its ease of deployment. Even so, there are some considerations involved in deployment, including deployment location. You can deploy a CASB either on-premises or in the cloud. Many CASB deployments are SaaS-based.

There are three basic CASB deployment models: 

  • API Control offers visibility into data and threats in the cloud, along with faster deployment and comprehensive coverage. 
  • Reverse Proxy is for devices outside the domain of network security.
  • Forward Proxy works in conjunction with VPN clients or endpoint protection. Often, proxy deployments enforce inline controls in real-time while complying with data residency requirements.

How CASB Integrates into SASE

CASB is a crucial aspect of SASE. Both CASB and SASE together can address all the requirements an enterprise WAN must meet to operate securely. 

SASE achieves this through its cloud-native security architecture, which simplifies the otherwise complex multi-point security solution issue. CASB adds a dedicated layer of cloud monitoring and applies security protocols that go beyond SASE capabilities alone. 

Together, they ensure data security, threat protection, network visibility, and compliance for both on-premises and cloud networks. All combined into an efficient, cloud-native multitenant platform.

CASB Considerations

CASB has several moving parts that need to integrate seamlessly, especially with SASE and SD-WAN. Securus Communications can help your organisation identify the most suitable CASB use cases and look for the solution that best addresses your goals.

Once we identify the CASB solution that will best suit your current and future needs, we can create a bespoke design to keep pace with growth.

Sadly, as your business grows, so will the threat landscape. Maintaining your cloud compliance and keeping your cloud security policies up to date comes as standard with Securus.


As data migrates towards Edge and Cloud computing, technologies such as SASE and CASB become a natural next step. The global edge computing market will reach $43 billion by 2027 and is growing at a rate of 37.4% per year. 

In 2020, the COVID-19 pandemic led to a necessary shift to remote work—to the edge. Further, many companies plan to continue with work-from-home policies even after the pandemic subsides. At Securus, we feel that this migration will mark a permanent shift of information that calls for cloud security technologies like CASB and SASE.

CASB has a critical role to play in both SASE and SD-WAN technology. With an effective CASB in place, your organisation can protect your growing list of SaaS applications, along with the users and systems that connect with them.

Please get in touch to discuss your networking requirements in more detail. We offer a completely free consultation with one of our technology experts to fully go over your precise needs.

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