Impact of PCI DSS on API Security For Mobility Products, Apps, and Services

The Payment Card Industry Data Security Standard (PCI DSS) is a global framework designed to protect payment card data across all environments that store, process, or transmit cardholder information. Maintained by the PCI Security Standards Council (founded by Visa, Mastercard, American Express, Discover, and JCB), it establishes twelve core security requirements covering network protection, access control, encryption, monitoring, and incident response.

The most recent version, PCI DSS v4.0, introduces a more flexible, outcome-based model that emphasizes continuous risk management, stronger authentication, secure software development, and Targeted Risk Analyses (Req. 12.3.2), all of which are highly relevant to API-driven mobility ecosystems.

Mobility services introduce unique API security challenges under PCI DSS, because they merge payment data with real-time mobility and IoT systems. This paper examines how the PCI DSS shapes and strengthens API security within connected mobility ecosystems, covering vehicles, mobile apps, mobility and transportation services, EV Charge Point Operators (CPOs), and supporting cloud services.  

The paper begins with a foundational overview of PCI DSS controls as they apply to APIs, then narrows in on the unique risks of mobility environments where payment, telematics, and IoT converge. Though PCI DSS is not a cybersecurity framework, it may have an impact on specific API transactions related to systems that connect to the Cardholder Data Environment (CDE). 

The paper next contrasts PCI DSS with automotive cybersecurity regulations UNECE R155 and R156, highlighting overlaps and areas of potential tension in scope, data handling, and change control. 

It concludes by exploring how a live digital twin of app consumers or connected products can serve as a powerful compliance and monitoring mechanism, bridging data-centric and system-centric security requirements across modern mobility architectures.

>> TLDR (Executive Summary)

The convergence of payments, mobility, and connected vehicle ecosystems has introduced new compliance and cybersecurity challenges. As APIs increasingly connect vehicles, mobile apps, and cloud platforms, the PCI DSS v4.0 plays a critical role in defining how cardholder data is protected in these distributed environments.

Key findings:

• Expanded API Scope Under PCI DSS v4.0: APIs that process, transmit, or even indirectly connect to cardholder data are now explicitly in scope, emphasizing strong authentication (Reqs. 7–8), encryption (Reqs. 3–4), and continuous testing (Req. 11).
  The following table offers a short overview of the mapping PCI DSS controls and OWASP API Top 10, globally recognized list published by the Open Worldwide Application Security Project (OWASP) that identifies and ranks the most critical security risks facing modern web and cloud APIs:

• Mobility-Specific Risks: Distributed, multi-partner ecosystems, such as automotive OEMs, payment providers, and EV charging networks, require segmentation, tokenization, and third-party attestation (Req. 12.8).
• Cross-Framework Alignment: PCI DSS complements UNECE R155/R156 by focusing on data integrity and monitoring, while R155/R156 emphasize lifecycle governance and OTA security. Together, they create a unified defense model for API-driven mobility services.
• Digital Twin for Compliance Monitoring: A live digital twin mirrors anonymized telemetry to give continuous visibility into PCI DSS controls, supporting compliance validation and early detection of anomalies.

Practical implications for mobility providers:

• Build APIs using security-first principles that integrate tokenization, least privilege, and secure Software Development Life Cycle (SDLC) practices.
• Classify APIs by PCI DSS scope, in-scope, connected, and out-of-scope, to reduce compliance overhead while maintaining security boundaries.
• Apply compensating controls for constrained environments, such as OTA pipelines, that cannot fully meet PCI DSS requirements.
• Leverage OWASP API Top 10 mappings to guide secure design and audit readiness.

Upstream’s AI-powered detection & response platform (XDR) provides centralized API visibility, contextual detection, and continuous compliance monitoring across connected fleets, apps, and services. By correlating API transactions, detecting anomalies, and mapping evidence directly to PCI DSS and UNECE control objectives, Upstream enables OEMs and mobility stakeholders to demonstrate compliance while proactively reducing risk.

The platform’s live digital twin, built-in API security, and cyber threat intelligence capabilities give compliance and cybersecurity teams real-time insight into payment-related data flows, helping them detect misuse, validate controls, and maintain segmentation across complex cloud and vehicle environments.

The Impact of PCI DSS on API Security: General Overview

The PCI DSS has a major impact on API security, especially for any organization that processes, stores, or transmits cardholder data. 

The current PCI DSS v4.0 introduces more flexible, outcome-based requirements, which are highly relevant to API-driven mobility ecosystems. Notably, v4.0 adds the concept of Targeted Risk Analyses (Req. 12.3.2), requiring organizations to define and justify customized controls based on their unique API risks. This is particularly important for distributed mobility environments where APIs connect vehicles, mobile apps, and cloud services with varying exposure levels.

Authentication and Access Control

PCI DSS Requirements:

• Enforce strong authentication and authorization (Req. 7 & 8).
• Limit access to cardholder data to only those who need it.
• Require unique IDs for each user and implement multi-factor authentication (MFA).

Impact on APIs:

• APIs must authenticate clients securely (e.g., OAuth 2.0, mutual TLS).
• Access tokens or keys must be rotated, revoked, and protected.
• Fine-grained role-based access control (RBAC) must restrict sensitive endpoints.

Data Protection and Encryption

PCI DSS Requirements:

• Protect stored and transmitted cardholder data (Req. 3 & 4).
• Mask or tokenize card data when possible.
• Use strong cryptography for encryption in transit (TLS 1.2+).

Impact on APIs:

• APIs must never transmit PANs (Primary Account Numbers) unencrypted.
• Sensitive data should be tokenized or truncated before exposure via APIs.
• All API communications must use HTTPS with TLS, no exceptions.

Logging, Monitoring, and Incident Response

PCI DSS Requirements:

• Track and monitor all access to network resources and cardholder data (Req. 10).
• Maintain audit logs and detect anomalies.

Impact on APIs:

• Every API call that accesses cardholder data must be logged with metadata (user, timestamp, action).
• API gateways or security platforms should detect and block suspicious patterns, e.g., brute-force or injection attempts.
• Logs must be tamper-proof and securely stored.

Secure Development Practices

PCI DSS Requirements:

• Develop and maintain secure systems and applications (Req. 6).
• Conduct regular code reviews and vulnerability assessments.

Impact on APIs:

• Implement input validation and output encoding to prevent injection.
• Conduct static and dynamic application security testing (SAST/DAST).
• Apply secure coding standards for APIs handling financial data.

Network Segmentation and Firewalls

PCI DSS Requirements:

• Protect cardholder data with firewalls and network segmentation (Req. 1).

Impact on APIs:

• APIs handling cardholder data must be deployed in segmented, protected zones.
• Public APIs should only expose non-sensitive endpoints.
• Use API gateways to enforce rate limiting, authentication, and security policies.

Continuous Compliance and Testing

PCI DSS Requirements:

• Regularly test security systems and processes (Req. 11).
• Perform penetration testing and vulnerability scans.

Impact on APIs:

• APIs must undergo regular penetration testing focused on OWASP API Top 10 threats.
• Use automated vulnerability scanning on API endpoints.
• Maintain compliance documentation for all third-party integrations.

Summary

PCI DSS pushes organizations to:

• Design APIs with security-first principles.
• Limit data exposure and enforce encryption at all layers.
• Continuously monitor API behavior for compliance and threats.

In essence, PCI DSS turns API security from a best practice into a regulatory requirement, especially for fintech, e-commerce, and payment processors.

The Impact of PCI DSS on API Security: Zooming in on Mobility Apps and Services

Amid the API security challenges of mobility services under PCI DSS, below is a breakdown of the distinct implications of PCI DSS on API security for this specific domain.

Distributed Ecosystem: Vehicles, Apps, and Edge Devices

Within PCI DSS assessments, APIs are classified based on their relationship to the CDE:

• In-scope APIs: Directly store, process, or transmit cardholder data (e.g., payment transaction APIs).
• Connected APIs: Indirectly impact the CDE through network connections, data exchange, or authentication dependencies.
• Out-of-scope APIs: Segmented systems that cannot affect the security of cardholder data, provided effective network isolation is in place.

Clear API scoping helps mobility providers accurately identify compliance scope while ensuring that adjacent systems, such as telematics or OTA services, do not introduce indirect risks.

PCI DSS Implications:

• Endpoints beyond the data center: Mobility APIs interact not only with web/mobile apps, but also with vehicles, IoT chargers, and telematics units, which may collect or transmit cardholder data.
• Requirements 1 & 12: PCI DSS demands segmentation and strict control over all components that touch payment data, even edge devices.

API Security Impact:

• Each vehicle or device acting as an API client must:
  • Use mutual TLS or certificate-based authentication to connect to payment APIs.
  • Avoid storing card data locally (e.g., on in-vehicle infotainment systems).
  • Ensure over-the-air (OTA) software updates are signed and validated to prevent compromise of payment-related endpoints.
• The API architecture must clearly isolate payment functions from mobility telemetry and infotainment APIs.

Mobile App and SDK Integration Risks

PCI DSS Implications:

• Requirements 3 & 4: Cardholder data must be protected wherever it’s handled, including in mobile SDKs that interact with APIs.
• Requirement 6: Secure development lifecycle applies to both the API backend and the mobile app that consumes it.

API Security Impact:

• APIs must ensure that mobile apps never directly handle PANs, use tokenization or payment gateways.
• Mobile SDKs must:
  • Use certificate pinning to prevent man-in-the-middle attacks.
  • Avoid hardcoding API keys or secrets in app code.
• All communications between the app and APIs must use TLS 1.2+, with certificate validation enforced at the client level.

Multi-Partner Ecosystems and Third-Party APIs

PCI DSS Implications:

• Requirement 12.8: Organizations are responsible for ensuring that third-party service providers handling cardholder data also comply with PCI DSS.
• Mobility ecosystems often involve payment providers, OEMs, charging networks, and fleet operators, each with their own APIs.

API Security Impact:

• APIs must authenticate and isolate partners via:
  • Separate API keys, scopes, or tenant IDs.
  • Data minimization: expose only what’s necessary.
• Use an API gateway to enforce consistent PCI DSS controls across all partners.
• Conduct regular vendor compliance verification (e.g., attestation of compliance, AOC) for integrated services.

Contextual Data Sensitivity: Location, Identity, and Payments

PCI DSS Implications:

• PCI DSS itself regulates cardholder data, but mobility systems mix this with personally identifiable information (PII) and location data.
• Combining these datasets amplifies privacy and data exposure risk beyond standard PCI boundaries.

API Security Impact:

• APIs must treat combined data payloads (e.g., trip info and payment token) as high-risk even if they contain tokenized card data.
• Implement data classification policies that elevate security controls for such combined contexts.
• Enforce fine-grained access control and data masking for analytics APIs.

Dynamic Environments: OTA Updates and Cloud-Native Deployments

It’s important to note that PCI DSS change control only applies to CDE-impacting changes, not all OTA. In addition, a payment microservice in the cloud may be in PCI scope but not R155 scope.

PCI DSS Implications:

• Requirement 11 & 6: Mandates ongoing vulnerability management and secure system updates.
• Mobility APIs often run in microservice or serverless architectures with frequent updates.

API Security Impact:

• All new API versions or deployments must undergo security testing before production rollout; payment APIs must also follow PCI DSS change control
• Use automated compliance scanning to detect drift from PCI DSS baseline configurations.
• Maintain immutable infrastructure for API servers that handle payment transactions.

When full PCI DSS compliance is technically infeasible, for example, in legacy OTA pipelines or constrained in-vehicle systems, organizations can use compensating controls such as:

• Signed update manifests with hash verification to ensure software integrity (addressing Req. 6 & 11).
• Network segmentation and proxy-based update distribution to maintain PCI isolation (Req. 1).
• Enhanced logging and automated anomaly detection on OTA endpoints to meet Req. 10 monitoring needs.
  These measures maintain equivalent security intent even in constrained mobility environments.

Tokenization and Payment Abstraction in Mobility Flows

PCI DSS Implications:

• PCI DSS encourages reducing scope through tokenization and payment orchestration.

API Security Impact:

• Mobility APIs should delegate card data processing to PCI DSS–certified payment gateways.
• Use transient tokens for payments initiated via vehicles or apps (e.g., EV charging built-in payment terminals, managing payment details and transactions as part of the data transmitted under OCPP to the CPO).
• Ensure that token exchange APIs are scoped, audited, and rate-limited to prevent abuse.

Compliance Architecture Considerations

Best Practices for Mobility PCI DSS Alignment:

• Design for least privilege: Vehicles and apps should only call APIs relevant to their operational role.
• Centralize audit and logging: Mobility platforms must correlate API activity from vehicles, apps, and payment systems for PCI logging (Req. 10). It’s recommended to avoid logging PAN or SAD (Sensitive Authentication Data); furthermore, correlating vehicle telematics with payment events creates re-identification risk and could expand PCI scope.
• Segregate environments: Keep PCI DSS, scoped systems separate from telematics, navigation, or entertainment networks.

Summary Table: PCI DSS ↔ Mobility API Impacts

PCI DSS vs. UNECE R155 & R156

While PCI DSS focuses on data confidentiality, R155/R156 focus on system resilience and operational security, yet both touch API security, software integrity, and threat management in connected mobility systems.

PCI DSS (data-centric, payment scope)

• Strict authentication & authorization: Unique IDs, MFA for admins, least privilege, short-lived tokens, key rotation (Req. 7–8).
• Data minimization & tokenization: Avoid PAN in APIs; tokenize, truncate; never log sensitive auth data (Req. 3–4, 10).
• Transport & storage crypto: TLS 1.2+ end-to-end, strong ciphers, HSM/KMS for keys (Req. 3–4).
• Change control & SDLC: Pre-prod reviews, SAST/DAST, dependency patch SLAs (Req. 6).
• Monitoring & auditability: Tamper-evident logs for all cardholder-data access; time sync; incident response (Req. 10, 12).
• Network segmentation: Isolate the CDE; API gateways as choke points (Req. 1).
• Third-party due diligence: Only integrate PCI-compliant providers; hold AOCs (Req. 12.8).

R155 (system-centric cybersecurity) & R156 (software updates)

• API threat modeling across the fleet: TARA for all vehicle/cloud/edge APIs (not just payments).
• Device & service identity: Mutual TLS, cert lifecycle for vehicles, chargers, mobile apps, suppliers.
• Telemetry for detection: Collect & correlate cybersecurity events; anomaly detection across ECUs/cloud.
• Safety + security by design: Secure coding, hardening, supply-chain integrity (SBOMs, signing).
• Update governance (R156): SUMS-backed rollout gates, cryptographic OTA validation, rollback plans for API clients and services.
• End-to-end risk ownership: OEM/type-approval holder accountable across lifecycle, not only merchant/payment zone.
• Partner isolation: Tenanting/scoping for multi-party ecosystems (OEMs, MSPs, charging networks).

Where Conflicts / Tensions Can Appear

1. Scope boundary
   • PCI DSS: Only systems touching cardholder data (CDE).
   • R155/R156: Whole vehicle ecosystem (incl. non-payment APIs).
   • Risk: Payment microservices “out of scope” for PCI may still be in scope for R155 threat surface.
   • Mitigation: Treat payment APIs as dual-scope; apply CSMS controls even when PCI segmentation excludes adjacent services.

1. Log retention & data minimization
   • PCI: Keep only what’s necessary; never store PAN/unmasked auth data; tight retention on CDE logs.
   • R155: Broader security telemetry retention to support forensics.
   • Mitigation: Log bifurcation: (a) CDE logs with PCI retention & redaction; (b) cybersecurity telemetry (no CHD) with longer R155 retention.

1. Change velocity vs. update rigor
   • PCI: Formal change control before prod for anything touching CDE.
   • R156: Rapid OTA/SUMS pipelines for safety/security updates.
   • Mitigation: Make PCI change gates part of SUMS: OTA or backend releases that affect payment paths require PCI checks (SAST/DAST, segregation tests) before deployment.

1. Threat focus
   • PCI: Confidentiality/integrity of card data.
   • R155: Broader operational / safety threats (e.g., spoofed API causing unsafe state).
   • Mitigation: Unified risk register merging PCI risks and TARA; ensure API abuse cases (rate-limit evasion, device cloning, replay) are covered from both angles.

1. Responsibility & contracts
   • PCI: Merchant/service provider model.
   • R155/R156: OEM/type-approval accountability.
   • Mitigation: Compliance demarcation in contracts + API boundaries: who owns which logs, certs, incident R&R, and update approvals.

Practical Mapping for API Security Teams

To bridge practical API security guidance with compliance obligations, this mapping contextualizes API-specific risks within the PCI DSS control framework, giving teams a direct path from OWASP mitigations to compliance evidence:

It’s All About Context: The Power of the Live Digital Twin in Mitigating PCI DSS Risks

Though PCI DSS does not recognize digital twins as a control, using a live digital twin of vehicles or app consumers to support PCI DSS compliance is very relevant to modern connected mobility architectures. 

Beyond its role in detecting fraud or API vulnerabilities and manipulations, a well-architected digital twin also serves as a continuous compliance monitoring layer. By mirroring API traffic, data flows, and behavioral telemetry, it provides real-time evidence for PCI DSS controls such as access monitoring (Req. 10), vulnerability management (Req. 11), and incident response (Req. 12). The digital twin acts as an observability proxy, helping compliance teams verify that controls remain effective without directly touching cardholder data systems.

When applied to PCI DSS–sensitive systems, the digital twin can function as a secure proxy and compliance observability layer, not as a data holder.

Essentially, the digital twin can serve as an early-warning system for cybersecurity or fraud events. It models normal vs abnormal API and payment flows, helping incident-response teams act quickly.

For example, if the digital twin indicates repeated failed authorizations from a single vehicle or device ID, it can:

• Flag a potential brute-force or credential-stuffing attempt.
• Trigger an automated response or API rate-limit adjustment.
• Generate an event for the PCI-required incident log.

The Result: Faster, evidence-backed response for PCI DSS and R155 alike.

To remain out of PCI DSS scope, the digital twin must be architected as a non-CDE component. It should receive anonymized or tokenized telemetry only, never live cardholder data, encryption keys, or authentication secrets.

The digital twin’s function is purely observational and analytic, it mirrors behavioral patterns and controls evidence but cannot alter, store, or forward payment data. Data flow diagrams and segmentation documentation should explicitly show unidirectional interfaces from the CDE to the digital twin, ensuring assessors can verify its out-of-scope status during PCI validation.

Summary of the benefits and impact of the digital twin:

Real-Life Case Study: Tech Prankster Sends 50 Robotaxis to a Dead End Street

In October 2025, a software engineer organized a “DDoS prank” in which approximately 50 people simultaneously ordered rides from a popular driverless fleet to a single dead-end street.

Although harmless in intent, the stunt temporarily overloaded the service’s dispatch and routing system, triggering a brief service disruption and automatic no-show fees. The robotaxi service responded by disabling pickups and drop-offs in the area until the next morning.

Even though this wasn’t a traditional cyberattack, it mimicked a distributed denial-of-service (DDoS) pattern at the application/API layer, with dozens of legitimate requests overwhelming a single backend function (ride dispatch).

While the event itself is not about payment data, PCI DSS provides a framework for resilience, authentication, and monitoring that applies directly to this kind of API abuse:

• Requirements 1 & 11: Firewalls and regular testing are required to detect and mitigate denial-of-service or abnormal traffic.
• Requirement 10: Continuous logging and anomaly detection, key to recognizing a DDoS or API-layer flood early.
• Requirement 12.10: Incident response planning, including procedures for isolating and recovering from network-layer or application-layer attacks.
• So even in a non-payment context, PCI DSS embodies defensive design and incident readiness that mitigate the same class of vulnerabilities exploited in such a prank.

Implications for API Security

A DDoS prank is fundamentally an API-availability threat, overwhelming endpoints with illegitimate traffic. From an API security standpoint:

• Rate limiting and throttling: Core control to prevent automated request floods.
• Traffic validation and auth: Mutual TLS or signed requests ensure only legitimate clients reach critical endpoints.
• Bot and anomaly detection: PCI DSS’s logging requirements align with API-gateway telemetry to spot unusual request patterns.
• Network segmentation: Isolating critical systems (like payment APIs or vehicle control endpoints) reduces blast radius.

Availability is part of trust. In mobility or payments, downtime equals lost revenue and degraded user confidence. A DDoS attack can severely disrupt fleet management APIs, blocking routing or ride requests. It can also affect payment or identity APIs, delaying transactions or user verification. Finally, it may undermine safety-critical communication channels, which both PCI DSS and automotive cybersecurity standards (R155/R156) emphasize must remain available and authenticated.

This DDoS case illustrates why mobility APIs should implement PCI-like rigor in:

• Segmentation between public and internal APIs,
• Real-time monitoring of endpoint behavior,
• Strict authentication and access control, and
• Clear incident response processes.

What began as curiosity mirrors real adversarial testing; under computer misuse laws, such pranks can breach authorization boundaries even without data theft.

Even though PCI DSS is about protecting cardholder data, its security controls, segmentation, monitoring, access control, and response planning directly strengthen defenses against the kind of API-level abuse and availability attacks seen in the DDoS prank.

This recent example is a vivid reminder that API resilience and integrity are part of compliance readiness, whether the standard is PCI DSS, R155, or any modern cybersecurity framework.