What Is a Cloud Access Security Broker (CASB)?

A Cloud Access Security Broker (CASB) is a cloud security checkpoint between users and cloud providers. It enforces security policy across an entire enterprise’s multiple cloud-based resources.

Rather than each cloud service provider using a different security policy, CASB consolidates standard security requirements across all users and providers. A wide-ranging CASB can authenticate users, enact data loss prevention, monitor and stop suspicious activity, prevent malware, and more. It enforces these policies across every user, device, and service.

CASBs are critical as enterprises rely more on cloud-based software and services, particularly with the increase in remote work and the growing threat of cyberattacks.

The quick answer: administrators create a list of security policies and use a CASB to enforce protocols between all users, devices, and cloud services. These policies can include:

• Scan shared data to automatically detect and flag personally-identifiable information.

• Detect account takeover behavior, like a user accessing a service from two different countries in one day.

• Require SSO and MFA across certain applications and users.

The exact process of creating and enforcing security policies using CASB looks like this:

1. Discovery: A CASB compiles all cloud-based services and applications along with identifying users accessing the data.

2. Classification: The CASB determines the risk factor of each cloud service based on the sensitivity of the data it contains and how it is shared.

3. Remediation: The CASB applies access controls and security policies to each cloud service.

Additional security policies CASB can enforce include encryption, logging, malware detection, and more. Once an organization has made its security requirements, CASB can immediately take action when a violation occurs and also notify administrators of the incident.

The foundation of an effective CASB solution is based on four pillars. Each pillar provides critical functionality to CASBs. Let's review each pillar and what they offer to cloud security.

• Visibility: An IT team needs to monitor cloud usage including who is accessing data, what device was used, and the location the access came from. The high level of visibility ensures administrators can detect suspicious activity including unauthorized devices or users. This means an IT team can make an informed decision about the authenticity of cloud activity.

• Compliance: Many industries are subject to compliance standards making it mandatory to implement appropriate safeguards to protect sensitive data. Ignoring compliance standards leads to a greater risk of a data breach as well as hefty fines from the enforcing organization. A CASB provides the necessary tools for organizations to stay compliant.

• Data Security: Organizations often store sensitive information in the cloud, making data security a priority. The seamless access to data off-premises has its benefits, but it often comes with increased security risks. CASBs can track any sensitive content interacting with the cloud. Combined with cloud data loss prevention (DLP), CASBs can spot malicious activity before it escalates into a full crisis.

• Threat Protection: Along with 24/7 monitoring, threat protection identifies threats across the internal and external network. It then handles the threat and notifies the administrators of the issue. For example, a CASB may notice an attempted login from a new device at an unfamiliar location. This has red flags of a potential threat, and the IT team is promptly notified.

With a holistic combination of all four pillars, a CASB can defend an organization's cloud infrastructure from multiple cyber threats and other security risks.

Organizations face a rise in remote work and employees using personal devices while relying on a growing number of cloud services. A CASB provides a solution to enact strict cybersecurity measures across a complex work landscape without compromising productivity.

Here are a few of the main benefits organizations can gain from implementing CASB:

• Securing sensitive data: CASB provides many security measures to protect sensitive data. Some of these measures include encryption at-rest and in-transit, privileged access management, and DLP.

• Governing cloud apps: CASB allows organizations to approach cloud usage based on factors such as identity, application, or data. Instead of blocking services, CASB provides granular visibility and control.

• Protecting against threats: CASB provides IT teams full visibility of cloud usage across all cloud-based apps and services, making it easier to notice unusual user behavior. Combined with tools like anti-malware detection and monitoring for compromised accounts, organizations can face the evolving landscape of cyber threats.

• Meeting compliance requirements: Organizations are often required to meet certain cybersecurity standards by government agencies. Using a cloud environment often comes with uncertainty about how to meet compliance requirements. CASB has the necessary configurations to maintain compliance.

The best use of CASB is to implement it with other data security technology and tools. This approach provides a multi-layered solution to keeping data secure. Every CASB provider has a different offering, and an organization should choose a CASB provider which meets its security needs.

Here are a few items to consider when choosing a CASB provider:

• Identify individual use cases: Your organization has specific needs other industries don't necessarily need to consider. Identifying your organization's use cases can help determine what features you need. For example, your organization may allow employees to use personal devices to access cloud email. Then you will need to ensure a CASB provider can protect a personal device from malware while maintaining employee privacy.

• Determine growth capabilities: Cyber threats are constantly evolving which means your cybersecurity strategy will need to evolve with it. This often means ensuring vendors in your supply chain, including CASB providers, are prepared to meet the challenge. A CASB provider should keep an organization in line with the latest capabilities and security policies.

• Consider deployment: CASB is an addition to your organization's cybersecurity investments, and it's important to ensure it enhances your cloud security. CASB providers will have different deployment models, and an organization should choose a model which works best for it and its security needs.

• Preferred deployment mode: CASBs can deploy as an inline proxy between the cloud service and the user, or outside of the traffic as an API. Each approach comes with pros and cons, and users can combine deployment modes depending on organizational needs.

Organizations must verify a CASB provider's abilities to deliver on advertised capabilities. A proof of value should offer a detailed breakdown of what a CASB offers, with specific discussions on deployment, architecture, and threats.