Cloud adoption has accelerated rapidly in recent years. By 2025, over 95% of new digital workloads will be deployed on cloud-native platforms, up from 30% in 2021 according to Gartner. However, this shift has also expanded the digital attack surface. Cloud-based threats and breaches are rising – 60% of companies suffered a cloud data breach in 2024 according to Oracle and KPMG.
Traditional security tools have blind spots when it comes to cloud risks. To close these gaps, organizations are turning to cloud access security brokers (CASBs). As an experienced information security architect who has implemented CASB solutions at over a dozen enterprises, I‘ve seen firsthand the unique protections and oversight CASBs provide.
In this comprehensive guide, I‘ll demystify CASBs – from how they work to their many benefits in securing cloud environments. I‘ll also offer advice on evaluating CASB vendors, architecting CASB POCs, and driving adoption. Let‘s dive in!
What are CASBs and Why are they Critical Today?
CASBs are cloud-based security solutions designed explicitly to secure data across cloud apps and infrastructure. As shown below, CASBs act as an intermediary between users and cloud providers:
Four factors are driving the urgent need for CASBs:
- Workforce mobility – Employees access cloud apps from anywhere on personal devices. Traditional network security can‘t adapt.
- Visibility gaps – Shadow IT leaves blind spots, obscuring high-risk services, unauthorized usage, and threats.
- Compliance risks – Data in the cloud must meet regulations like HIPAA, PCI DSS, SOX. CASBs help avoid violations.
- Data breaches – Cloud accounts are increasingly targeted. CASBs prevent compromised credentials from exfiltrating sensitive data.
While organizations utilize dozens of cloud services on average according to Skyhigh Networks, most IT teams only have visibility into sanctioned applications like Office 365 and Salesforce. CASBs close these visibility and control gaps.
Core CASB Capabilities and Architecture
CASBs secure cloud access via four core capabilities:
Cloud Discovery – Detect shadow IT by scanning network traffic, endpoint software, and cloud provider APIs. Inventory all cloud services in use and the data stored.
Data Security – Classify, monitor, and protect sensitive data across cloud apps. Encrypt data and integrate with DLP tools.
Threat Prevention – Block compromised user accounts, malware campaigns, unauthorized access. "Zero trust" model.
Compliance Enforcement – Ensure cloud apps comply with regulations. Continuously audit configurations and activity.
Under the hood, CASBs provide these controls using a proxy architecture:
Traffic flows through the CASB security stack to enforce policies before reaching cloud apps. CASBs scan content for malware, detect unauthorized usage, match sensitive data patterns, log activity, encrypt content, and block unsanctioned apps.
APIs are leveraged to embed controls directly into cloud platforms when proxies aren‘t feasible. For example, configuring access restrictions and DLP policies within Infrastructure as a Service environments like AWS.
Key Benefits of Adopting a CASB
Based on my experience, CASBs offer enterprises these major benefits:
360-degree cloud visibility – Discover all cloud services in use across the organization. Classify risk levels associated with apps, users, and data. Identify unsecured access channels.
Stop data leakage – Data loss prevention integration extends leak protection to the cloud. Create and enforce context-aware controls on sensitive and confidential data.
Protect against threats – Leverage threat intelligence to detect compromised accounts, risky user behaviors, and malware. Alert, block, and automatically remediate threats.
Simplify regulatory compliance – Continuously audit cloud app security configurations against frameworks like SOC2, ISO 27001, FedRAMP, and more. Furnish detailed reports required for audits and oversight.
Enable digital transformation – Adopt new cloud services with confidence by layering on robust security controls that don‘t inhibit user productivity.
Consolidate tools – CASBs integrate with existing security stacks, centralizing visibility, management, analytics, and controls across endpoints, networks, and clouds.
Choosing a CASB Deployment Model
CASBs integrate within an organization‘s infrastructure and cloud footprint in a few different ways:
API Access – CASB connects to cloud app APIs to monitor configurations, user activity, and content. Simple to implement but limited in control capabilities.
Forward Proxy – CASB is placed between internal users and the internet. All outbound traffic is routed via the CASB for inspection and policy enforcement.
Reverse Proxy – Rather than sending all traffic to the CASB, it proxies access to approved apps while blocking unsanctioned ones. Maintains user experience.
Inline – CASB is physically installed inline as an on-premises network appliance. Maximizes control for internal traffic but can‘t secure external access.
Choosing the right model involves tradeoffs between control, visibility, performance impact, and ease of deployment. For most organizations, I recommend starting with a hybrid forward and API proxy architecture. This balances visibility, control and implementation complexity.
Evaluating CASB Vendors
The CASB market has matured with over a dozen vendors now competing on advanced capabilities. Here are key criteria I advise clients to consider when selecting a CASB platform:
- Deployment flexibility – Assess proxy, reverse proxy, API, and inline options
- Threat prevention prowess – Compare threat intel, user/entity behavior analytics, zero trust capabilities
- DLP integration – Review sensitive data type classifiers, optical character recognition, contextual policies
- App support – Coverage for popular SaaS, IaaS environments, custom apps
- Compliance certifications – Auditing, reporting, and configuration scanning depth
- Actionable insights – Intuitive visibility into high-risk users, apps, and data
- 3rd party integration – API support for SIEM, SOAR, and enterprise software ecosystems
- Customer support -Technical expertise and enterprise-friendly SLAs
Leading CASB vendors include Bitglass, Netskope, Zscaler, and Proofpoint. Evaluate product strengths like Netskope‘s patented SSE technology and Bitglass‘ agentless reverse proxy against your unique requirements.
Best Practices for CASB Adoption
Based on successful customer deployments, here are my top tips for driving CASB adoption:
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Start with a proof of concept (POC) – Prove CASB value and build internal support with a targeted 3-4 week pilot focused on high-risk use cases like guest user access.
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Plan for integration – Architect how the CASB will integrate ahead of time. Identify any network topology changes needed, endpoint software requirements, and integration touchpoints with SIEM, DLP, and proxy tools.
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Phase rollout – Gradually ramp CASB coverage based on risk profile. Start with sanctioned cloud apps accessed externally, then unsanctioned apps, remote workers, etc.
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Incentivize business units – Encourage CASB adoption by highlighting benefits like improved operational performance, reduced compliance overhead, and accelerated cloud projects.
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Communicate proactively – Socialize the CASB with transparency around deployment plans and goals. Show how it will augment – not hinder – business cloud usage.
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Involve counterparts – Partner closely with network operations and identity management teams during planning and rollout. Streamline change management.
Monitor effectiveness – Track adoption, policy triggering trends, and metric improvements during rollout to guide fine-tuning and demonstrate wins.
The Future of Cloud Security is CASB
In closing, CASBs have become an essential element of cloud security technology stacks. Analysts predict the CASB market will exceed $10B by 2025 as cloud adoption continues accelerating.
CASBs uniquely fill the cloud visibility, data security, threat protection, and compliance gaps inherent in first-generation cloud offerings. While CASBs emerged as a new product category, they complement existing tools through integration and API expansion.
With comprehensive control and oversight across sanctioned and shadow cloud apps, CASBs strengthen security postures for modern enterprises. I strongly recommend considering a CASB to achieve end-to-end protection as you migrate business-critical data and workloads to the cloud.