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Updated: Apr 11, 2024   |   Alex Yong

What is a Cloud Access Security Broker (CASB), and How Does It Work?

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  • CASBs are essential for organizations to maintain compliance and to secure and protect data in the cloud.
  • They provide visibility, compliance assurance, data security, threat protection, and governance.
  • CASBs act as intermediaries, enforce security policies, and extend security controls to the cloud.
  • CASBs differ from SIEM systems in focus, function, and capabilities.
  • The four pillars of CASB are compliance, deep visibility, data protection, and threat detection.

A Cloud Access Security Broker (CASB) is a crucial tool for organizations that aim to maintain compliance with regulations and effectively safeguard their data in the cloud. By offering a comprehensive set of security features and functionalities, CASBs play a vital role in enabling professionals in the field to address the complex challenges associated with cloud computing.

In today's highly interconnected digital landscape, organizations often rely on cloud services to store and process their sensitive data. However, this reliance also introduces significant security risks, such as unauthorized access, data breaches, and non-compliance with industry regulations. To mitigate these risks, professionals in the field turn to CASBs to provide them with the necessary tools and capabilities. CASB works by:

  • Visibility and Control: Cloud Access Security Brokers (CASBs) are a crucial part of an overall data protection strategy and provide organizations with visibility into their cloud application usage, allowing them to monitor and control access to cloud services and data.
  • Compliance Assurance: They help enforce compliance policies across cloud environments, ensuring that data storage and processing meet regulatory standards like GDPR, HIPAA, and others.
  • Data Security: CASBs protect sensitive information from unauthorized access and data breaches by encrypting data, implementing data loss prevention (DLP) strategies, and controlling the sharing of data.
  • Threat Protection: They offer threat detection and mitigation capabilities to protect against malware, ransomware, and other cyber threats in cloud applications and services.
  • Identity and Access Management: CASBs manage and secure user identities and access privileges, integrating with existing identity providers to ensure that only authorized users can access cloud resources.
  • Activity Monitoring and Analytics: They provide detailed logs and analytics on user activities within cloud services, enabling organizations to detect suspicious behaviors and potential security incidents.
  • Cloud Governance: CASBs enforce governance policies to manage cloud resource usage effectively, optimizing cloud operations and ensuring that cloud services are used in a secure and compliant manner.

Understanding the Role of a CASB


What does a CASB do?
Cloud Access Security Broker - part of a holistic data protection strategy
CASBs act as an intermediary between cloud service providers and cloud users, allowing organizations to extend their security policies and controls to the cloud environment. They act as a gatekeeper, monitoring and enforcing security measures, such as authentication, authorization, and encryption, to ensure that only authorized users can access and manipulate data in the cloud.

Moreover, CASBs enable professionals to gain greater visibility into their cloud environments from a cloud data security perspective. Through advanced monitoring and analytics capabilities, they provide real-time insights into user activities, data usage patterns, and potential security threats. This enhanced visibility empowers professionals to detect and respond to suspicious activities promptly, preventing potential data breaches and other security incidents.

Another essential aspect of CASBs is their ability to enforce data compliance with industry regulations and data privacy laws. By integrating with existing security systems and leveraging advanced policy enforcement mechanisms, CASBs enable professionals to ensure that their cloud deployments adhere to regulatory requirements, such as GDPR, HIPAA, and PCI DSS. This capability not only helps organizations avoid costly fines but also enhances their reputation as trustworthy custodians of sensitive data.

Exploring the Functionality of Cloud Access Security Brokers

Cloud Access Security Brokers (CASBs) operate as security policy enforcement points between cloud service consumers and cloud service providers. They act by integrating with existing network and security architectures, utilizing APIs and proxy modes to monitor and manage the data traffic that flows into and out of cloud applications.

CASBs offer granular visibility into cloud application usage, enabling security professionals to identify and assess the risk of shadow IT. They leverage advanced security controls, including encryption, tokenization, and data loss prevention (DLP) mechanisms, to protect sensitive data from unauthorized access or leaks. Additionally, CASBs incorporate user behavior analytics (UBA) and threat intelligence to detect and mitigate anomalous activities and potential cyber threats.

By enforcing access policies based on user identity, device, and location, CASBs ensure:

  • only authorized users gain access to cloud resources.
  • cloud and SaaS adoption is secure and in compliance with regulatory requirements.

Their role is pivotal in extending an organization's security policies beyond its traditional boundaries to encompass the distributed nature of cloud computing.


Comparing CASB and SIEM: Key Differences

Cloud Access Security Brokers (CASB) and Security Information and Event Management (SIEM) systems are both crucial components of an organization's security architecture, yet they serve distinct roles and address different aspects of security and compliance.

  • CASB (Cloud Access Security Broker) primarily focuses on securing cloud services.
  • SIEM (Security Information and Event Management) provides a comprehensive view of an organization's information security, covering both on-premises and cloud environments.
  • CASB is specifically designed for cloud security, while SIEM offers broader security monitoring capabilities.
  • CASB helps organizations secure cloud applications and data, while SIEM helps in monitoring and managing security incidents across the entire IT infrastructure.
  • CASB is more specialized towards cloud security, whereas SIEM is a more general security monitoring and management tool.

Primary Function and Focus

CASBs are security policy enforcement points that sit between cloud service users and cloud service providers to extend the reach of security policies beyond the traditional corporate network. They focus specifically on managing and securing cloud application usage, providing visibility into shadow IT, enforcing data governance, compliance, threat protection, and assessing the security posture of cloud services.

SIEM systems aggregate and analyze log and event data from various sources within an organization’s IT infrastructure, including network devices, systems, and applications, whether on-premises or in the cloud. The primary function of SIEM is to provide real-time monitoring, event correlation for security incident detection, and to facilitate incident response. SIEM systems are broader in scope, focusing on the overall security landscape of an organization.

Security Capabilities

CASB offers specific controls for cloud services, such as data loss prevention (DLP), encryption, access control, and threat protection tailored to the cloud. Working in conjunction with DLP and IRM solutions, CASBs are adept at identifying risky cloud services, unauthorized access, and securing sensitive data in the cloud.

SIEM focuses on the aggregation of security data from across the network to identify anomalous behavior and potential security incidents. SIEM solutions use correlation rules and analytics to alert on potential threats, providing a centralized view for security operations teams.

Compliance and Governance

CASB helps enforce compliance with data privacy regulations specifically in cloud environments by monitoring and controlling the movement and storage of sensitive data across cloud applications and services.

SIEM facilitates compliance reporting and auditing across an organization’s entire IT environment by collecting and analyzing log data to demonstrate adherence to various regulatory requirements.

Deployment and Integration

CASB integrates with cloud service providers through APIs or via proxy, acting as a gatekeeper for data being accessed or moved across cloud services.

SIEM requires integration with a wide array of data sources within an organization's network, including logs from firewalls, network devices, servers, and now, increasingly, cloud services.

Breaking Down the 4 Pillars of CASB

  • Compliance: Ensuring adherence to industry regulations and standards.
  • Deep Visibility: Providing detailed insight into cloud usage and data flow.
  • Data Protection: Safeguarding sensitive information through encryption and access controls.
  • Threat Detection: Identifying and responding to security threats in real-time.

Implementing a Comprehensive Strategy for Data Protection

CASBs are indispensable tools for professionals in the field who seek to maintain compliance with regulations and protect their data in the cloud. By providing robust security features, enhanced visibility, and regulatory compliance capabilities, CASBs enable organizations to confidently embrace cloud computing while effectively managing associated risks and challenges.

  • It enables the governance of cloud usage across various devices and applications.
  • CASBs also provide protection against security threats that may arise in cloud environments.
  • As more businesses transition to cloud services, CASBs are increasingly vital for enhancing security measures.

Next DLP's Reveal is an intuitive and comprehensive data loss prevention solution that delivers immediate value to organizations. It is designed to educate employees, identify potential risks, and implement data handling policies effectively to avert data breaches.

Reveal ensures thorough data protection and cloud security by offering complete oversight. Reveal, which is complementary to a CASB solution, ensures thorough data protection and cloud security by offering complete oversight. It incorporates unobtrusive agents and cloud sensors that are capable of identifying attempts at data exfiltration and executing automated policy application. Utilizing machine learning and sophisticated cloud sensors, it proactively identifies potential risks, preventing them from escalating into security breaches. This solution is versatile, supporting various operating systems including Windows, macOS, and Linux and the most popular business SaaS applications.

The Reveal solution facilitates an end-to-end data protection strategy by detecting and inventorying data, classifying it according to customizable rules, applying data handling policies to minimize risky behaviors, and promptly alerting cybersecurity teams to potential incidents, mapped to the MITRE ATT&CK framework, for swift investigation.

Additionally, it plays a crucial role in fostering a culture of cybersecurity awareness among employees. Discover how Next DLP's Reveal can safeguard your organization's critical data. Schedule a demo to see our solution in action.


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