Whether you’re migrating from on-premises to the cloud, between cloud providers, or to more advanced cloud architectures, each path shares common security challenges that must be addressed head-on.
With the right approach, you can actually enhance your security posture during migration. In this article, we'll dig into practical approaches to cloud migration security, covering everything from initial planning to post-migration maintenance. Whether you're performing a simple lift-and-shift or completely refactoring your applications for cloud-native architectures, you'll find actionable strategies to protect your workloads at every stage of the journey.
What is cloud migration security, and what are its benefits?
Cloud migration security is a set of strategies, controls, and best practices to protect data, applications, and infrastructure when moving to the cloud. Security is often treated as an afterthought—a checkbox to tick post-deployment—but teams need to reframe it as a continuous process integrated throughout the migration lifecycle, not a one-time task. When security is treated as a secondary concern, it not only creates vulnerabilities but also leads to expensive rework and potential incidents.
Instead, embedding security by design from day one means fewer surprises and smoother operations down the line. Your cybersecurity needs to adapt before, during, and after you move your assets to the cloud.
A robust cloud migration security strategy delivers several critical benefits:
Risk mitigation: Proactively identifying and addressing security gaps prevents data breaches and service disruptions that could damage your reputation and bottom line.
Regulatory compliance: Industries face different regulatory requirements—from HIPAA in healthcare to GDPR for SaaS companies to PCI DSS for payment processing. A security-first approach ensures you maintain compliance throughout the transition.
Customer trust: Your users trust you with their data. Maintaining strong security during migration preserves that trust and demonstrates your commitment to protecting their information.
Operational continuity: A secure migration minimizes unexpected downtime and service degradation, allowing your business operations to continue without major disruptions.
Cost savings: Addressing security issues during migration is significantly cheaper than fixing them after an incident occurs. The average cost of a data breach now exceeds $4.5 million—a compelling reason to invest in security upfront.
Key security considerations for different types of cloud migration
Your approach to security will be based on your migration strategy—whether you're lifting and shifting existing applications, refactoring for cloud-native architectures, or building a hybrid solution. Cloud architectures demand different security approaches. Let's break down the key considerations for the most common migration scenarios.
On-prem to cloud migration
Moving workloads from your data center to a cloud provider introduces a shift in the security paradigm. You're trading physical control for shared responsibility, where your provider handles some security aspects while you manage others.
This transition creates potential attack surfaces as data moves across environments and new access patterns are created. For these types of migrations, key security priorities include:
Data encryption: Implement end-to-end encryption for data at rest and in transit. In the cloud, security becomes a shared responsibility between you and your provider. Don't assume your cloud provider handles encryption automatically—review their encryption standards and supplement where necessary.
Identity management: Cloud environments introduce new potential entry points through APIs, identity systems, and network connections that likely don’t exist in your on-prem environment. Overhaul your authentication and authorization frameworks to accommodate cloud-specific access patterns. Consider implementing single sign-on (SSO) solutions that work across environments.
Secure APIs: APIs serve as important integration points during cloud migration, functioning as the primary interfaces between services and systems. Cloud environments introduce inherently dynamic infrastructure where resources are created, scaled, and destroyed automatically in response to demand. This difference in architecture requires security controls designed to adapt to this constant change rather than traditional static services and their defenses. Secure these critical boundaries with robust authentication mechanisms, rate limiting, and comprehensive input validation to prevent unauthorized access and abuse.
Zero trust architecture: Moving to the cloud can affect your regulatory compliance status, potentially introducing new requirements around data privacy, encryption standards, and access controls. Adopt the "never trust, always verify" principle by implementing network segmentation, just-in-time access, and continuous verification of every access attempt.
Application hardening: Review and update your applications for vulnerabilities that become more exposed in cloud environments. Focus on securing your code dependencies, container security, and runtime environments, as these areas present the highest risk during cloud transitions and are frequently targeted by malicious actors.
Cloud-to-cloud migration
When moving between cloud providers or regions, you're dealing with provider-specific security implementations and navigating the complexities of extracting your data from one environment and safely transferring it to another.
Security priorities for cloud-to-cloud migrations include:
Data transfer security: Data in transit between cloud environments can be vulnerable to interception, especially when using default migration tools that may route through public networks. Establish secure channels for moving data between clouds, potentially using dedicated interconnects or VPN tunnels to avoid public internet exposure.
Configuration consistency: Security configurations can vary dramatically between providers. Document your security requirements and ensure they're consistently implemented in the target environment. Even seemingly identical security features like network security groups or IAM policies have subtle differences that can create unexpected vulnerabilities.
Key management: Securely migrate encryption keys and secrets without exposing them during the transition. Consider using a dedicated key management service that works across cloud environments.
Interoperability risks: Security teams frequently struggle with incompatible logging formats, different permission models, and inconsistent API behaviors that can hide suspicious activities during and immediately after migration. Address potential security gaps created by differences in how cloud service providers implement authentication, network controls, or monitoring capabilities.
Compliance alignment: Verify that your new cloud environment supports the same compliance requirements as your source environment, particularly for regulated industries.
Hybrid cloud and multi-cloud migration
Unlike intentional migrations, hybrid and multi-cloud environments often emerge organically through acquisitions, incomplete migrations, or strategic decisions to leverage specific provider capabilities. These complex architectures require specialized security approaches to bridge fundamentally different security models:
Unified security policies: Implement consistent security policies across all environments to prevent configuration drift and security gaps.
Network segmentation: Carefully design network boundaries between environments, using dedicated connections and traffic filtering to control data flows.
Consistent identity framework: Deploy a centralized identity solution that works across all environments to prevent authentication silos and access control inconsistencies.
Latency and monitoring: Monitor blind spots and latency issues that can impact security visibility across distributed environments.
Workload portability: Design security controls that move with your workloads, allowing applications to maintain their security posture regardless of where they're deployed.
Common security risks during cloud migration
Engineering teams often face similar security challenges when transitioning to the cloud. Let's dive into the most common challenges:
Cloud migration security risks
Data breaches and leaks
Data becomes particularly vulnerable to breaches and leaks when teams overlook encryption requirements or misconfigure access controls. These security lapses can expose sensitive information, violate regulatory requirements, and have significant legal consequences. To protect against these risks, organizations should implement robust end-to-end encryption for data in transit and at rest, conduct regular access reviews, and deploy data loss prevention (DLP) tools to detect and block unauthorized data transfers.
Misconfigurations
Cloud security misconfigurations often stem from human error, a lack of standardization, or a misunderstanding of cloud provider security models. These mistakes can increase your attack surface, enable unauthorized access to resources, and potentially expose sensitive data to malicious actors. Organizations can substantially reduce these risks by implementing infrastructure-as-code with security scanning, establishing baseline secure configurations, and deploying cloud security posture management (CSPM) tools that continuously monitor for and alert on any deviations from your defined security baseline.
Inadequate access control
Often access control is jeopardized when there are over-privileged accounts, insufficient just-in-time access mechanisms, and inconsistent policy enforcement as workloads move between environments. These can give unauthorized users access to sensitive resources, create opportunities for privilege escalation attacks, and make it nearly impossible to maintain least-privilege principles across your infrastructure. Effective mitigation requires implementing comprehensive role-based access control (RBAC) with clear separation of duties, utilizing temporary credentials with precise expiration times for specific migration tasks, and enforcing strong authentication mechanisms including multi-factor authentication (MFA) for all administrative access.
Downtime and data corruption
Handling data improperly during migration, inadequate testing, or poorly designed rollback procedures can lead to significant service interruptions and loss of data integrity. Organizations should protect against these risks by thoroughly testing all migration procedures in staging environments, maintaining comprehensive backups with clear rollback procedures, and considering blue-green deployments that allow for immediate rollback if issues arise.
Regulatory non-compliance
Many organizations struggle with regulatory compliance during cloud migrations because they fail to properly translate how compliance requirements map to cloud environments or neglect to maintain consistent controls during transition periods. Compliance lapses can result in severe regulatory penalties, suspending important certifications, and potential restrictions on business operations in regulated industries. Organizations should develop a compliance matrix that maps regulatory requirements to specific cloud controls, work with compliance experts during planning, and validate compliance posture after each migration phase.
Cloud migration security checklist
Breaking down the cloud migration process into clear phases helps teams cover all security bases before, during, and after the transition. Here's a practical checklist to guide your migration journey:
Pre-migration (planning and assessment)
Conduct a comprehensive risk assessment to identify security gaps and vulnerabilities
Classify data and workloads by sensitivity and compliance requirements
Choose a cloud provider that aligns with your security and regulatory needs
Develop a detailed migration plan with defined security milestones and owners
Implement identity and access management (IAM) frameworks
Perform security audits on existing infrastructure to establish baselines
Encrypt sensitive data at rest and in transit
Establish backup and disaster recovery protocols with documented testing procedures
During migration (execution and monitoring)
Use secure transfer protocols with encryption for all data migration activities
Verify logging and monitoring tools are properly configured and actively collecting data
Monitor data movement in real time with alerts for anomalous patterns
Apply micro-segmentation to limit lateral movement across environments
Validate data integrity after each migration phase using checksums or other verification methods
Restrict access to cloud migration tools and sensitive systems to only essential personnel
Update security policies and documentation to reflect the evolving environment
Implement continuous security testing as components move to the cloud
Post-migration (validation and ongoing management)
Conduct a full security audit on the new cloud environment comparing against pre-migration baselines
Verify data integrity and confirm no data loss or corruption occurred during transition
Validate compliance with all relevant regulations through control mapping
Implement continuous monitoring and threat detection tuned for cloud environments
Test incident response plans and disaster recovery procedures in the new environment
Schedule security training for teams on cloud-specific security controls and best practices
Optimize cloud configurations to minimize attack surface
Review IAM policies to identify and remediate over-permissioned accounts
This checklist serves as a starting point. Customize it to match your specific migration scenario, cloud provider requirements, and organizational security standards.
8 best practices for ensuring security during cloud migration
The checklist is a great starting point, and let’s dive deeper into eight best practices that successful teams implement to ensure secure migrations:
1. Perform risk assessments
Map your assets and identify security dependencies before making any moves. A strategic risk assessment exposes potential vulnerabilities and helps prioritize security controls. Focus on identifying critical data flows, authentication dependencies, and potential compliance impacts to build a risk-based migration roadmap.
2. Encrypt everything
Default to encryption for all data—both in transit and at rest. Verify encryption methods and key management procedures. For particularly sensitive workloads, consider implementing application-level encryption alongside provider-managed solutions.
3. Automate security monitoring
Manual security checks don't scale during complex migrations. Implement automated security scanning and continuous monitoring to detect anomalies in real time. Use cloud-native security services alongside your existing tools to get comprehensive visibility as your environment evolves.
4. Utilize developer tools
Embed security into your development pipeline with security scanning, vulnerability assessments, and automated compliance checks. Tools can help enforce security policies during deployment, preventing misconfigurations before they reach production.
5. Implement continuous monitoring
Maintain visibility throughout the migration with comprehensive logging and monitoring. Ensure security telemetry flows from both on-premises and cloud environments into a unified monitoring solution. Set up alerts for suspicious activities, configuration changes, and potential security policy violations.
6. Segment networks
Create security zones with appropriate access controls and inspect traffic moving between environments. This limits lateral movement and contains potential breaches during the transition period.
7. Conduct regular security audits
Schedule periodic security assessments throughout the migration process—not just at the beginning and end. These regular check-ins help identify emerging risks and validate that security controls are functioning as expected in your evolving environment.
8. Don't forget about training
Cloud security requires different skills and knowledge than traditional infrastructure. Invest in training your team on cloud security principles, provider-specific security controls, and secure development practices for cloud infrastructure. Well-trained teams make fewer security mistakes during migration and respond more effectively to incidents.
Implementing these practices will protect your data and applications throughout the transition to the cloud. Remember that cloud security is a shared responsibility—understanding where your accountability begins and ends with your provider is critical to maintaining a strong security posture.
How Cortex can help with cloud migration security
Securing cloud migrations requires comprehensive visibility, consistent policy enforcement, and continuous validation. Cortex is an internal developer portal with features designed to address the specific security challenges that arise throughout cloud migration journeys. Engineering teams use Cortex to maintain security integrity across all phases of migration:
Before migration: Cortex helps teams catalog existing applications, dependencies, and security controls to establish accurate migration plans with security built in from the start. Our Service Catalog provides clear visibility into your existing environment, so you can identify security requirements and dependencies before the transition begins.
During migration: Cortex provides a unified view of your infrastructure across integrated tools, so you can identify potential security gaps and ensure alignment with organizational standards throughout the migration process. With Workflows, teams can automate routine tasks and enforce security policies consistently across all services to minimize human error and ensure security measures are applied during and after migration.
During and after the migration: Cortex maintains ongoing security oversight with Scorecards that enable teams to define and enforce security standards by automatically assessing services against predefined criteria. Initiatives allow you to carve off specific rules, tiers, or set a deadline to complete an entire Scorecard. Assign owners and due dates to ensure meaningful progress against any project—no matter how complex.
Ready to see how Cortex can secure your cloud migration journey? Book a demo today to learn how our platform can help your team migrate to the cloud with confidence.
