Public cloud adoption continues to surge, with IDC forecasting global spending on public cloud services to reach $1.3 trillion by 2028. Even as investments grow and organizations increasingly migrate to the cloud, security breaches remain a persistent and costly challenge.

According to IBM’s 2024 Cost of a Data Breach report, 40% of breaches involved data stored across multiple environments—including public and private cloud—and breaches in public cloud alone cost organizations an average of $5.17 million. It took an average of 258 days to identify and contain a breach, with those involving stolen credentials taking up to 292 days. Given these facts, strengthening public cloud security is no longer optional. If you manage cloud environments, the stakes involve protecting sensitive data, ensuring compliance, and maintaining business continuity.

This comprehensive guide focuses on actionable steps to secure your organization’s data and infrastructure on AWS, Azure, and Google Cloud. Let’s dive right in.

Navigating the Risky Waters of Public Cloud Security

Enterprises flock to public cloud services to scale, innovate, and stay agile. However, moving data and applications outside your on-premises perimeter creates unique security exposures. Attackers target misconfigured cloud storage, overly permissive access controls, and vulnerable API endpoints.

Public cloud security transcends simple checkbox compliance. Cloud environments evolve rapidly, with new attack surfaces emerging often. Keeping pace demands not only tools and platform knowledge but also skilled talent focused on continuous monitoring and incident response.

Making Sense of the Shared Responsibility Model

The single biggest misunderstanding around public cloud computing security involves the division of responsibility. Public cloud providers offer a robust security backbone, but protecting workloads, data, and access within your chosen service lies squarely with you.

  • Provider Responsibility (AWS, Azure, Google Cloud): Infrastructure security, physical security, foundational networking, and hypervisor patching.
  • Customer Responsibility (You): Identity and access management (IAM), data classification and encryption, OS and application patching, workload configuration, and monitoring.

Each major provider offers training and documentation on this split. However, your organization remains ultimately accountable for what happens inside your workloads. Never assume “default secure.”

AWS Security Considerations That Go Beyond Basics

With nearly 33% of the cloud market, AWS often makes headlines both for innovative features and for incidents resulting from weak configurations. Move from theory to practice by focusing on these actionable tips:

Lock Down IAM and Access Controls

  • Principle of Least Privilege

Assign users, services, and roles only the permissions they require. Use AWS IAM policies to limit actions. Rely on groups rather than individuals. Review policies quarterly.

  • Multi-Factor Authentication (MFA)

Enforce MFA for all users, especially root accounts. Implement hardware MFA where possible for administrative roles.

  • Access Analyzer

Use AWS IAM Access Analyzer to detect overly permissive policies and quickly remediate risky settings.

Secure S3 Buckets and Data Storage

  • Public Access Block

Activate S3 Block Public Access on every bucket unless strong business justification exists. Automate alerts for public S3 buckets using AWS Config rules.

  • Encryption at Rest and in Transit

Default to SSE-S3 or SSE-KMS for encryption at rest and require HTTPS (TLS 1.2+) for data transfers.

  • Object Versioning and Logging

Enable versioning to protect against accidental or malicious deletion, and activate server access logging for traceability.

Monitor, Detect, and Respond

  • GuardDuty and CloudTrail

Enable AWS GuardDuty for anomaly detection and CloudTrail for comprehensive activity logging across your account. Funnel critical alerts to your security operations team.

  • Security Hub and Config

Leverage AWS Security Hub as a central view for compliance. Use AWS Config to track resource changes and enforce secure baselines.

  • Automate Remediation

Use AWS Lambda functions to automatically remediate common misconfigurations, for example, revoking open public bucket permissions.

Control Network Access

  • VPC Segmentation

Architect workloads using multiple VPCs and subnets to isolate traffic. Only expose required services to the public internet.

  • Network Access Control Lists (NACLs) and Security Groups

Reduce attack surfaces by tightly defining inbound and outbound rules. Deny by default, allow by exception.

Azure Security Considerations for Real-World Environments

Azure’s popularity in government and regulated industries makes it a frequent choice for the public sector. The breadth of services are sometimes daunting, but focus efforts on these security tactics:

Identity Management and Conditional Access

  • Azure Active Directory (AAD)

Integrate all authentication with AAD for centralized control. Deploy Conditional Access policies to enforce location- and device-based restrictions. Use Privileged Identity Management (PIM) to provide just-in-time admin access.

  • Passwordless and MFA

Deploy passwordless sign-ins via Microsoft Authenticator or FIDO2 security keys. Enforce MFA policies for every user and guest.

Secure Data Everywhere

  • Encryption and Key Management

Azure Storage offers encryption at rest by default with customer-managed keys available via Azure Key Vault. Rotate keys regularly and restrict vault access.

  • Blob Storage Configuration

Restrict blob access using Shared Access Signatures (SAS) with regulated expiry and tight IP scopes.

Network Security Excellence

  • NSGs and ASGs

Build granular Network Security Groups (NSGs) to control VM traffic, and Application Security Groups (ASGs) for dynamic grouping based on service type.

  • Azure Firewall and DDoS Protection

Deploy Azure Firewall for advanced threat protection. Enable DDoS Protection Standard for mission-critical applications.

Visibility, Monitoring, and Response

  • Azure Monitor and Sentinel

Centralize logging with Azure Monitor and integrate Sentinel for SIEM/SOAR capabilities. Set up automated incident responses to reduce mean time to detect and recover.

  • Security Center Recommendations

Review Azure Security Center’s secure score dashboard weekly, prioritize findings, and immediately fix critical vulnerabilities.

Google Cloud Security Considerations for Effective Protection

Google Cloud’s reliability and innovation appeal to digital-first organizations. Protecting assets on GCP involves:

IAM Mastery and Zero Trust Networking

  • IAM Fine-Tuning

Utilize Google Cloud IAM’s predefined roles for every service. Restrict service account usage and rotate keys regularly. Use Organizational Policy Service to set org-wide limits on risky permissions.

  • BeyondCorp and Zero Trust

Move away from legacy VPNs. Implement BeyondCorp principles, limiting access based on context-sensitive data like user identity, device posture, and location.

  • VPC Service Controls

Use VPC Service Controls to build security perimeters and prevent data exfiltration between Google-managed services.

Encryption and Data Loss Prevention

  • Default and Customer-Managed Encryption

Google Cloud encrypts all data at rest and in transit. For sensitive workloads, use customer-managed encryption keys (CMEK) and hardware security modules.

  • Data Loss Prevention API

Identify, classify, and redact sensitive information (PII, PHI, PCI) automatically using DLP API for compliance-heavy workloads.

Monitoring and Incident Response

  • Cloud Audit Logs and Security Command Center

Enable Cloud Audit Logs for every resource. Deploy Security Command Center for a unified risk dashboard, vulnerability management, and automated alerting.

  • Event Threat Detection

Use Google’s Event Threat Detection to identify and respond to threats across your workload in real time.

Best Practices to Lock Down Data in Any Public Cloud

Public cloud security does not rely solely on provider tools. Leverage platform strengths while implementing universal controls to safeguard data.

Establish Rigorous Identity Governance

  • Use Single Sign-On (SSO) and federated identity to unify authentication.
  • Adopt just-in-time (JIT) access for elevated privileges and require regular review of admin assignments.
  • Institute strong password policies and work to eliminate static credentials.

Enforce Consistent Encryption

  • Apply encryption to data at rest with customer-managed keys for high-impact workloads.
  • Require TLS 1.2 or higher for all network traffic; enforce mutual TLS (mTLS) for inter-service communication.

Regularly Audit Configurations and Permissions

  • Run Cloud Security Posture Management (CSPM) tools weekly to detect drift or risky changes.
  • Use vulnerability scanning across all container images and serverless functions.
  • Create automated workflows to revoke permissions not used in the last 90 days.

Build Security Into the CI/CD Pipeline

  • Integrate static code analysis for security bugs early in the development cycle.
  • Scan cloud resource templates for misconfigurations at every pull request.
  • Require security regression testing before deploying to production.

Monitor Continuously, Respond Rapidly

  • Centralize logging and alerting with SIEM tools that aggregate across all providers.
  • Tune alert thresholds regularly to cut down on noise and reduce alert fatigue.
  • Build playbooks—for ransomware, insider threats, and cloud credentials leaks—that define roles and immediate remediation steps.

Why Skilled Talent Remains the Secret to Public Cloud Security

Automation and tools only solve part of the cloud security equation. You need experienced professionals who understand the nuances of public cloud computing security. Response times shrink and misconfigurations drop when your team includes cloud specialists trained to recognize evolving threats.

Organizations that operate in the public sector face rigorous compliance and confidentiality requirements. Sourcing experts, especially those who understand regulations like FedRAMP, HIPAA, or CJIS, presents an ongoing challenge. This is where partnership with a staffing firm specialized in the public sector delivers value. Such expertise ensures both strategic planning and operational resilience.

Do not overlook the advantage that cloud security managed services bring, especially in lean IT environments. These firms provide 24/7 monitoring, incident response, and domain-specific consulting tailored to government and education sectors.

Build a Secure Future Partnered for Success

Securing your cloud assets requires more than checking off compliance boxes. Robust public cloud security, especially in AWS, Azure, and Google Cloud, demands hands-on controls, continuous monitoring, and skilled professionals. Whether you manage identity, configure networks, or audit applications, your task is to maintain a vigilant, iterative approach.

Regularly review documentation, monitor provider updates, and test your incident response. As threats grow more sophisticated, so too must your cloud security strategy. Consider working with a staffing firm specialized in the public sector to access talent that understands the stakes and deliver results.

Take the next step toward public cloud security resilience. Partner with a staffing firm specialized in the public sector. Reach out now to explore how cloud security managed services and dedicated professionals empower your organization to thrive even as the cloud landscape shifts.

About Centurion Consulting Group

Centurion Consulting Group, LLC, a Woman-Owned Small Business headquartered in Herndon, VA conveniently located near Washington D.C., is a national IT Services consulting firm servicing the public and private sector by delivering relevant solutions for our client’s complex business and technology challenges. Our leadership team has over 40 years of combined experience, including almost 10 years of a direct business partnership, in the IT staffing, federal contracting, and professional services industries. Centurion’s leaders have the demonstrated experience over the past three decades in partnering with over 10,000 consultants and hundreds of clients from Fortune 100 to Inc. 5000 firms –in multiple industries including banking, education, federal, financial, healthcare, hospitality, insurance, non-profit, state and local, technology, and telecommunications. www.centurioncg.com.