Open Charge Point Interface (OCPI) is an open protocol for exchanging data between electric vehicle charging networks and e-mobility service providers. It carries roaming, location, tariff and session information, so defenders should protect API authentication, authorisation and data integrity. Weak implementation can expose charging records, enable fraudulent access or disrupt billing and settlement.
What OCPI enables in roaming and settlement
Open Charge Point Interface is designed to let charging networks and e-mobility service providers exchange structured operational data in a common format. That makes inter-company interoperability possible, but it also means the interface becomes part of the trust boundary for customer-facing charging, billing and settlement workflows.
Because OCPI is a protocol rather than a product, the security question is less about the name itself and more about how each implementation handles authentication, authorization, message integrity and partner trust. A weak implementation can turn routine roaming data exchange into a source of fraud, exposure or billing disputes.
Why OCPI security matters
OCPI traffic can carry location, tariff, session and roaming information that directly affects whether charging sessions are accepted and how they are billed. If a partner connection is manipulated, an attacker or misconfigured integration can distort records, suppress charges, or create false confidence in who is allowed to use a charging service.
That risk is similar to other API-mediated business exchanges: the protocol may be open, but the business value behind it is sensitive. Defenders should treat the OCPI boundary as a high-value integration point and OWASP API Security Top 10 as a useful lens for broken authentication, broken authorization and sensitive-flow abuse.
How organisations assess exposure
Exposure review starts with knowing which parties can connect, which endpoints are internet-facing, and which data objects the implementation exposes. That means inventorying partner integrations, validating authentication mechanisms, and confirming that each roaming relationship is limited to the minimum data and actions it actually needs.
For a protocol that carries operational records, the most important check is whether the implementation trusts partner assertions too broadly or accepts unauthenticated or weakly authenticated traffic. General control guidance from NIST SP 800-53 Rev 5 Security and Privacy Controls helps frame those reviews across access control, identification and authentication, audit, and system integrity.
Remediation, detection and post-incident review
When OCPI cannot be patched or reworked immediately, compensating controls should reduce trust in the integration path rather than assume the protocol is safe by default. Segmentation, strict partner allowlisting, short-lived credentials where possible, strong logging, and integrity checks on billing-relevant records all help limit the blast radius of a compromised connector.
Detection should focus on unusual session patterns, abnormal tariff changes, unexpected roaming authorisations, repeated failed calls, and inconsistencies between charging activity and settlement records. If compromise is suspected, review the downstream identity and access material tied to the integration, including API keys, certificates, tokens and service accounts that may need rotation or revocation.
Risk and Threat Considerations
OCPI is attractive to abuse because it sits directly on the path between service delivery and payment. If authentication or authorization is weak, an attacker or rogue integrator can tamper with charging records, harvest operational data, or cause financial and customer-impacting fraud.
Failure mechanism: A partner endpoint, token, or message flow is trusted more than it should be, allowing forged requests, replayed data, or manipulated settlement information to be accepted as legitimate.
Impact: The result can be exposure of charging records, unauthorized session control, incorrect billing, settlement disputes, and loss of trust between roaming participants.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP API Security Top 10 addresses the attack and risk surface, while NIST SP 800-53 Rev 5 and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP API Security Top 10 | API2 — Broken Authentication | OCPI relies on authenticated API exchanges between roaming partners. |
| API5 — Broken Function Level Authorization | OCPI operations must restrict who can change tariffs, sessions, or roaming data. | |
| API8 — Security Misconfiguration | OCPI deployments often fail through exposed endpoints, weak trust settings, or insecure defaults. | |
| Recommendation — Enforce strong partner authentication and reject requests that cannot be tied to a trusted OCPI peer. Restrict partner actions to the OCPI functions each integration is allowed to perform. Harden OCPI endpoints, partner trust settings, and transport controls before exposing the interface. | ||
| NIST SP 800-53 Rev 5 | IA-2 — Identification and Authentication (Organizational Users) | OCPI operators and platform admins need strong identity controls around partner-facing API management. |
| IA-9 — Service Identification and Authentication | OCPI is a machine-to-machine protocol between systems, so service authentication is central. | |
| AU-2 — Event Logging | OCPI risk depends on logging partner calls, session changes, and settlement-relevant events. | |
| Recommendation — Require strong authentication for staff who administer OCPI integrations and trust relationships. Authenticate OCPI services and peers before accepting roaming, tariff, or session data. Log OCPI partner activity and security-relevant data changes for traceability and review. | ||
| NIST CSF 2.0 | PR.AA-05 — Assets are protected using authentication and access management | OCPI requires controlled access to partner APIs and billing-relevant records. |
| Recommendation — Apply access management controls to OCPI integrations and partner data flows. | ||
Practitioner Guidance
Why practitioners should care: OCPI is a business-critical interoperability layer, so security failures can show up as both cyber risk and revenue risk. Treat partner onboarding, API trust, and data validation as core control decisions, not just integration details.
What to watch for: Pay special attention to broad partner privileges, long-lived credentials, weak auditability, and any implementation that accepts roaming data without strong validation of source and integrity.
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