Banks across Europe are modernizing their technology infrastructure to improve operational efficiency, accelerate digital banking, and deliver better customer experiences. Cloud computing plays a central role in this shift, enabling financial institutions to scale applications, process data more efficiently, and adopt new digital capabilities.
But cloud adoption also introduces a critical question: How can banks modernize their infrastructure without creating new cybersecurity risks?
A misconfigured cloud storage environment, excessive user permissions, an exposed application programming interface (API), or an overlooked third-party dependency can expose sensitive financial data and disrupt essential banking services. These risks become more complex when cloud platforms must operate alongside legacy banking systems, multiple vendors, and strict regulatory obligations.
For European financial institutions, cloud security is therefore not just an infrastructure concern. It is central to cybersecurity, operational resilience, and digital transformation.
The answer is not to slow down cloud adoption. It is to build security into every stage of the modernization journey.
Why Cloud Security Matters for European Banks
Cloud services offer financial institutions scalability, access to advanced security capabilities, flexible infrastructure, and improved disaster recovery options. However, these benefits depend on how cloud environments are designed, configured, monitored, and managed.
The European Central Bank (ECB), in its Guide on outsourcing cloud services to cloud service providers, recognizes the advantages of cloud adoption while highlighting challenges related to provider concentration, cloud-specific risks, monitoring, and oversight.
The European Banking Authority (EBA) has also highlighted the risks associated with financial institutions’ growing dependence on external ICT service providers, including cloud providers.
For banks, insurers, payment service providers, and fintech companies, these dependencies create several interconnected challenges:
- Cloud misconfigurations: Publicly accessible storage, overly permissive network rules, and insecure default settings can expose sensitive data or workloads.
- Unclear security responsibilities: Banks may assume their cloud provider manages more security controls than it does.
- Legacy system dependencies: Older banking applications can complicate cloud migration, identity management, network segmentation, and security monitoring.
- Third-party exposure: Cloud platforms, software vendors, managed service providers, and subcontractors introduce additional dependencies.
- Operational resilience: A security incident, configuration error, or provider outage can affect services that customers and business operations depend on.
These challenges make cloud security an essential consideration for organizations investing in cloud services in Europe.
- Cloud Misconfigurations: Small Errors Can Create Significant Exposure
Cloud environments can change rapidly. Teams provision resources, deploy applications, modify access permissions, and connect new services to meet business requirements.
Without consistent security controls, these changes can introduce vulnerabilities.
For example, a storage resource containing customer information might be configured with excessive access permissions. A cloud-hosted banking application could expose an administrative interface to the public internet. An inactive account might retain access to sensitive systems long after an employee or contractor has left.
Individually, these may appear to be manageable technical issues. Together, they can create attack paths that expose customer information, disrupt applications, or allow unauthorized access.
How Sphinx can reduce a bank’s cloud misconfiguration risks
Financial institutions should establish a consistent approach to cloud security posture management (CSPM). This involves continuously identifying insecure configurations, evaluating them against approved policies, prioritizing risks, and tracking remediation.
Practical measures include:
- Establishing secure configuration baselines for cloud resources.
- Continuously monitoring permissions, network exposure, storage settings, and encryption configurations.
- Using automated policy checks to identify deviations from approved standards.
- Prioritizing vulnerabilities based on business criticality, data sensitivity, and potential impact.
- Rechecking configurations after remediation to confirm that identified issues have been resolved.
Cloud security assessments can help banks uncover gaps that routine operational monitoring may overlook.
The objective is not simply to identify misconfigurations. It is to prevent recurring errors and make secure configurations a standard part of cloud operations.
- The Shared Responsibility Model: Who Is Accountable for Security?
One of the most common misunderstandings in cloud adoption concerns the division of security responsibilities between a financial institution and its cloud service provider.
Cloud providers secure aspects of the underlying infrastructure according to their service model. However, customers generally remain responsible for important controls such as identity permissions, data classification, application security, and the configuration of services they use. The precise division varies across infrastructure-as-a-service (IaaS), platform-as-a-service (PaaS), and software-as-a-service (SaaS) offerings.
Consider a bank hosting a customer-facing application on a public cloud platform. The provider may secure the physical data centers and underlying infrastructure, while the bank remains responsible for application-level access, appropriate data handling, and many workload-specific security settings.
If the bank grants excessive permissions or exposes sensitive data through an application, the cloud provider’s infrastructure security alone will not prevent the resulting exposure.
How Sphinx assists banks to strengthen cloud security accountability
Banks should document security responsibilities for every major cloud service and ensure that technical controls match those responsibilities.
Key measures include:
- Maintaining a clear responsibility matrix across cloud providers, internal IT teams, security teams, and external vendors.
- Enforcing least privilege access so users and applications receive only the permissions required for their roles.
- Implementing multifactor authentication and strong privileged-access management.
- Reviewing access permissions regularly and removing unnecessary accounts and credentials.
- Validating security controls through independent assessments and periodic testing.
Security responsibilities should also be reflected in contracts, operational procedures, incident-response arrangements, and supplier reviews.
Cloud outsourcing does not remove a bank’s responsibility for managing its own risks. Clear accountability is essential to ensuring that security control remains effective as cloud environments evolve.
- Legacy Banking Systems: The Hidden Complexity of Cloud Migration
Many financial institutions operate a combination of modern applications, legacy core banking systems, older databases, and specialized third-party platforms.
Moving these environments to the cloud is rarely a simple infrastructure exercise. Applications may rely on outdated authentication mechanisms, undocumented integrations, rigid network configurations, or data flows that were designed for a traditional data center.
If banks migrate these workloads without understanding their dependencies, they can carry existing security weaknesses into the cloud or introduce new ones.
For example, an older application may depend on a shared service account with broad permissions. When connected to a modern cloud environment, that account could create unnecessary access to other applications or sensitive resources.
How Sphinx follows a security-led approach to banking modernization
Before migrating critical workloads, banks should assess application dependencies, data sensitivity, access requirements, and potential failure scenarios.
A structured approach includes:
- Discover and classify assets: Identify applications, databases, interfaces, users, and third-party connections.
- Assess migration risks: Evaluate outdated components, insecure protocols, unsupported software, and existing vulnerabilities.
- Design secure cloud architecture: Define network boundaries, identity controls, encryption requirements, and monitoring capabilities.
- Modernize where necessary: Refactor or replace components when migration alone would preserve significant security weaknesses.
- Validate before production: Test application security, access controls, recovery procedures, and system integrations before moving critical workloads into live operations.
This approach allows banks to combine cloud migration with meaningful security improvements rather than simply relocating existing risks.
For institutions planning Digital Transformation Services in Europe, cybersecurity should be embedded in the modernization roadmap from the beginning.
- Protecting Financial Data Through Identity, Encryption, and Workload Security
Cloud environments host sensitive information, including customer records, transaction histories, financial documents, and internal business data. Protecting this information requires multiple layers of security rather than reliance on a single technology.
4.1. Identity and access management
Compromised credentials and excessive permissions can give attackers access to cloud resources without exploiting a traditional infrastructure vulnerability.
Banks should implement strong identity and access management (IAM), multifactor authentication, privileged-access controls, and regular entitlement reviews. Workload identities and service accounts should also be restricted to the minimum permissions necessary.
4.2. Encryption and data protection
Sensitive information should be protected both in transit and at rest using appropriate encryption controls. Banks should also define how encryption keys are stored, accessed, rotated, and recovered.
Data classification and retention policies help ensure that customer information receives protection proportionate to its sensitivity.
4.3. Cloud workload protection
Virtual machines, containers, serverless applications, databases, and APIs require security controls suited to their individual risks.
Banks should use vulnerability scanning, endpoint and workload protection, secure application configurations, and continuous monitoring to identify weaknesses before they become incidents.
4.4. Continuous monitoring
Centralized logging and security monitoring help teams identify suspicious access, unexpected configuration changes, and unusual workload activity.
The value of these controls depends on how effectively alerts are investigated, incidents are escalated, and remediation is completed.
Together, these measures help establish a stronger security foundation for cloud-based banking services.
- DORA and Cloud Security: Turning Regulatory Expectations into Operational Readiness
The European Union’s Digital Operational Resilience Act (DORA) has applied since 17 January 2025. It establishes requirements for ICT risk management, incident handling, resilience testing, and ICT third-party risk management for financial entities within its scope.
DORA is particularly relevant to cloud adoption because financial institutions increasingly depend on external providers for technology services that support important business functions.
Compliance is not achieved simply by selecting a cloud provider with strong security certifications. Banks must understand their own dependencies, evaluate provider risks, maintain appropriate oversight, and establish arrangements for responding to disruptions.
Relevant considerations include:
- ICT risk management: Identify and assess risks affecting cloud-hosted applications, infrastructure, and information assets.
- Third-party oversight: Evaluate providers, contractual arrangements, subcontracting dependencies, and the risks associated with critical services.
- Incident management: Define how cloud-related incidents are detected, escalated, reported where required, and resolved.
- Resilience testing: Test relevant systems, controls, and recovery arrangements according to the institution’s risk profile and applicable requirements.
- Exit and recovery planning: Establish workable strategies for recovering data, transitioning services, or exiting arrangements without unacceptable disruption.
The ECB’s supervisory priorities for 2026–28 include follow-up on cybersecurity and third-party risk management, as well as supervisory work examining banks’ preparedness for potential disruptions caused by a major cloud service provider.
For European banks, this reinforces the need to connect cloud security governance with practical operational resilience.
DORA applies according to the relevant entity’s regulatory scope and requirements. Banks should assess their specific obligations rather than assume that one standard approach applies to every financial institution.
- Cloud Concentration Risk: What Happens If a Critical Provider Becomes Unavailable?
Cloud security discussions often focus on preventing unauthorized access. But resilience also depends on what happens when a provider experiences an outage, a critical service becomes unavailable, or a dependency can no longer be used.
Financial institutions may rely on a limited number of major providers for infrastructure, identity services, data storage, security tools, and business applications. A disruption affecting one provider or interconnected service can therefore have consequences across multiple operations.
Using multiple cloud providers is not automatically the answer. A poorly designed multi-cloud environment can increase complexity, create inconsistent security policies, and make incident response more difficult.
Instead, banks should understand their critical dependencies and determine how much disruption they can tolerate.
Practical steps include:
- Mapping cloud services to the business functions they support.
- Identifying dependencies on providers, regions, identity platforms, and external integrations.
- Defining recovery time objectives and recovery point objectives for critical workloads.
- Testing backups and restoration procedures rather than assuming that backups are usable.
- Evaluating alternative recovery arrangements and provider exit strategies where appropriate.
- Conducting exercises that test technical recovery and coordination between business, IT, security, and supplier teams.
The goal is to build resilience proportionate to business criticality, not to eliminate every dependency at any cost.
- DevSecOps: Building Security into Every Stage of Cloud Modernization
Traditional security reviews conducted shortly before deployment can struggle to keep pace with modern development and cloud delivery cycles.
DevSecOps addresses this challenge by integrating security practices into software development, infrastructure provisioning, testing, and deployment.
For banks, this means identifying security issues earlier and reducing the likelihood that insecure code, vulnerable dependencies, or unsafe configurations reach production.
A practical DevSecOps program from Sphinx can include:
- Infrastructure-as-code scanning to identify insecure cloud configurations before deployment.
- Automated software composition analysis to detect vulnerable third-party dependencies.
- Static and dynamic application security testing.
- Secrets management to prevent credentials from being embedded in code.
- Automated policy enforcement within CI/CD pipelines.
- Controlled deployment processes, audit trails, and post-deployment monitoring.
Automation should support security teams rather than replace risk-based decisions. Critical findings still require appropriate prioritization, investigation, and remediation.
By embedding security into development and operations, financial institutions can modernize applications more consistently while reducing avoidable security weaknesses.
A Practical Cloud Security Checklist for European Banks
Before expanding cloud adoption or migrating critical workloads, banking leaders can use the following checklist to identify areas that require further assessment.
- Are all cloud assets, applications, and critical dependencies documented?
- Are cloud configurations continuously checked against approved security baselines?
- Are identity permissions, privileged accounts, and service credentials appropriately restricted?
- Is sensitive financial data classified, encrypted, and subject to appropriate access controls?
- Are legacy applications and their cloud integrations assessed before migration?
- Are cloud providers and other ICT suppliers monitored according to their risk and business criticality?
- Are incident-response procedures defined and tested for cloud-related disruptions?
- Have critical backup and recovery procedures been tested?
- Are security checks integrated into software development and infrastructure deployment?
- Can the organization demonstrate how cloud risks are identified, prioritized, remediated, and reported?
A negative answer does not automatically indicate a regulatory breach. It identifies an area where the institution may need further investigation, control improvements, or specialist support.
How Sphinx Team Can Help Banks Modernize with Confidence
Cloud security requires coordination across architecture, infrastructure, application development, identity management, compliance, and operational risk. Internal teams may have strong expertise in individual areas but still benefit from an independent view of the complete environment.
Professional cloud security services can help financial institutions identify weaknesses, validate existing controls, and develop a prioritized improvement roadmap.
Depending on the institution’s needs, support may include:
Cloud security assessments: Review cloud configurations, access permissions, network exposure, workload protection, and monitoring to identify security gaps.
Cloud architecture reviews: Evaluate the security and resilience of cloud designs, migration plans, application integrations, and critical dependencies.
Cybersecurity services in Europe: Support financial institutions with risk assessments, vulnerability management, security testing, incident-response readiness, and broader cybersecurity improvement programs.
DevSecOps implementation: Integrate security testing and configuration checks into development and deployment pipelines.
Cloud compliance support: Map relevant security controls to applicable regulatory and internal requirements, helping teams document evidence and prioritize remediation.
Cloud resilience and recovery reviews: Assess backup arrangements, recovery plans, provider dependencies, and the ability to maintain critical services during disruptions.
For banks pursuing cloud adoption, these services help connect technology modernization with measurable security and resilience objectives.
Conclusion: Make Cloud Security Part of the Modernization Strategy
Cloud adoption can help European financial institutions improve scalability, support innovation, and modernize customer-facing services. But these benefits depend on how well security, governance, and operational resilience are integrated into the transformation.
Misconfigurations, excessive permissions, legacy dependencies, unclear responsibilities, and provider concentration can create risks that are difficult to manage through isolated security tools alone.
The more effective approach is to establish security baselines, maintain visibility across cloud assets, enforce least-privilege access, protect sensitive data, automate security checks, and regularly test recovery capabilities.
Most importantly, banks should treat cloud security as an ongoing discipline rather than a one-time migration activity.
For organizations evaluating cloud services in Europe or planning wider Digital Transformation Services, the question is not simply whether workloads can move to the cloud. It is whether those workloads can operate securely, withstand disruption, and meet the institution’s business and regulatory needs.
Modernization and security should advance together. With the right architecture, controls, and specialist expertise, banks can move towards the cloud without losing sight of what matters most: customer trust, data protection, and the continuity of financial services.
Frequently Asked Questions
- What is cloud security in banking?
Cloud security in banking refers to the policies, technologies, and processes used to protect cloud-hosted financial applications, customer data, infrastructure, and services against unauthorized access, cyberattacks, data exposure, and operational disruption.
- What are the biggest cloud security risks for European banks?
Key risks include cloud misconfigurations, excessive access permissions, insecure APIs, legacy system vulnerabilities, third-party dependencies, inadequate monitoring, and weaknesses in backup and recovery arrangements.
- How does DORA affect cloud security for European financial institutions?
DORA establishes requirements for ICT risk management, incident handling, resilience testing, and third-party risk management for financial entities within its scope. Banks must maintain appropriate oversight of cloud-related risks even when technology services are outsourced.
- What is the shared responsibility model in cloud security?
The shared responsibility model defines which security controls are managed by the cloud provider, and which remains the customer’s responsibility. The division depends on the cloud service model and the specific services being used.
- How can banks secure cloud migration?
Banks should assess existing applications and dependencies, classify sensitive data, design secure cloud architectures, enforce least-privilege access, test migrated workloads, and validate monitoring and recovery procedures before moving critical systems into production.
- When should a bank consider professional cloud security services?
Professional support can be valuable before a major migration, when introducing new cloud platforms, after significant architecture changes, when addressing assessment findings, or when internal teams need independent validation of security controls and resilience arrangements.
