Open Charge Point Interface is a protocol for communication between e-mobility service providers and charge point operators. It handles functions such as locations, sessions, tariffs and status exchange. Security teams should protect authentication, API access and transport security, because exposed interfaces can reveal infrastructure data, enable fraudulent charging activity or disrupt availability.
How OCPP works as a charging-operations protocol
Open Charge Point Interface is the common message layer between an e-mobility service provider and a charge point operator. In practice, it lets back-end systems exchange information about charging points, active sessions, tariffs, availability, and remote commands. It is not just a connectivity detail, it is the operational control plane for how charging infrastructure is discovered, managed, and billed.
The protocol matters because both sides depend on timely, reliable state changes. A station that reports the wrong status can misroute drivers, create failed sessions, or hide outages. A back-end that applies the wrong tariff or command can affect revenue, service quality, and trust in the charging network.
What data OCPP exchanges and why it matters
OCPP typically carries a narrow but business-critical set of objects: charge point identity, location information, availability, meter values, session start and stop events, tariffs, diagnostics, and status updates. Those messages let the operator run the fleet centrally while still leaving the station in the field.
That centralisation is useful, but it also makes the protocol a dependency for core operations. If status exchange fails, the operator loses visibility into whether a charger is idle, occupied, faulted, or compromised. If session data is delayed or altered, settlement and customer support become harder to trust.
Because OCPP exposes an API-style interface, OWASP API Security Top 10 is a useful way to think about the most relevant abuse cases, especially broken authorisation, unsafe consumption, and inventory gaps.
Why security controls are part of OCPP design, not an add-on
Security is integral because OCPP links billing, physical assets, and networked control. Authentication prevents unauthorised systems from pretending to be a legitimate operator or charge point. Transport protection helps keep commands and telemetry from being observed or altered in transit. API access control limits which systems can query status, start sessions, or change configuration.
That is why teams should treat OCPP like any other sensitive operational interface rather than a passive integration. A weak trust boundary can expose site details, enable fraudulent charging activity, or allow an attacker to disrupt availability by manipulating session state or remote control messages.
For identity and session assurance, OpenID Connect Core 1.0 illustrates how authentication can be layered on top of token-based flows, while NIST SP 800-63 Digital Identity Guidelines helps teams think about assurance and phishing-resistant authentication where human operators administer the platform.
Where OCPP deployments fail in practice
Most failures are not protocol theory problems, they are deployment problems. Common weaknesses include overly broad API access, weak certificate or token handling, poor inventory of connected chargers, and inconsistent configuration between field devices and the back end. Those gaps make it harder to know which stations are reachable, which commands are valid, and which messages should be trusted.
Fraud and disruption often follow the same pattern: an exposed management path, a weakly protected interface, or a poorly segmented control plane. Once that path exists, the attacker does not need to break the electrical system, only the software relationship that governs it.
NIST Cybersecurity Framework 2.0 is helpful here because OCPP deployments need the basics to be explicit: asset visibility, access control, monitoring, response, and recovery. For organisations using cloud-hosted back ends, the NIST AI Risk Management Framework is not the primary fit, but the broader discipline of governance and accountability remains a useful operational reference when automation decides how infrastructure behaves.
Risk and Threat Considerations
OCPP creates a high-value trust path because it bridges remote software control and real-world charging activity. If authentication or authorisation is weak, an attacker may be able to impersonate a trusted party, read operational data, alter session state, or interfere with charging availability.
Failure mechanism: The interface becomes exploitable when exposed APIs, weak credentials, missing transport protections, or poor inventory allow unauthorised systems to send or replay trusted operational messages.
Impact: The result can include fraudulent charging, leaked infrastructure intelligence, incorrect billing, service disruption, or broader loss of trust in the charging network.
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 surface, NIST SP 800-63 and NIST CSF 2.0 set the technical controls, and ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP API Security Top 10 | API5 — Broken Function Level Authorization | OCPP exposes operational functions that need strict caller authorization. |
| Recommendation — Enforce function-level authorization on every OCPP command and admin action. | ||
| NIST SP 800-63 | IAL — Identity Assurance Level | Admin access to charging back ends depends on trustworthy operator authentication. |
| Recommendation — Use strong operator authentication and assurance for back-end administration. | ||
| NIST CSF 2.0 | PR.AA-05 — Identity Management, Authentication, and Access Control | OCPP deployments need controlled access to chargers, APIs, and session-management functions. |
| DE.CM-01 — Networks and network services are monitored to detect potential cybersecurity events | OCPP traffic and control actions need monitoring for misuse and abnormal charging activity. | |
| Recommendation — Restrict OCPP access paths to authorised systems and identities only. Monitor OCPP traffic and state changes for anomalous commands and sessions. | ||
| ISO/IEC 27001:2022 | A.8.24 — Use of cryptography | Transport protection is needed to keep OCPP messages confidential and integral in transit. |
| Recommendation — Protect OCPP traffic with cryptography appropriate to the deployment. | ||
Practitioner Guidance
What to verify: Confirm that every OCPP endpoint is authenticated, that the charge point inventory is complete, and that remote commands are limited to the minimum operational scope required. If you cannot explain which back-end can talk to which charger and why, the deployment is already too permissive.
Decision rule: If a charger or back-end interface can affect session start, stop, tariff, or configuration state, treat it as production control traffic and review it with the same care you would give a privileged administrative API.
What good looks like: Operators can prove which stations are online, which sessions are active, which commands were issued, and which identities are allowed to issue them, without relying on manual reconstruction after an incident.
Practitioner takeaway: The security question is not whether OCPP is “just a protocol”, it is whether the protocol boundary is strong enough to preserve billing integrity, operational visibility, and trustworthy remote control.
Related resources from NHI Mgmt Group
- Open Charge Point Interface (OCPI)
- How can organisations keep credentials from becoming a remote-work weak point?
- How should security teams evaluate open weight models for code review work?
- How do organisations decide whether a platform approach is better than isolated point solutions for enterprise work?