OAuth (Open Authorization) is an industry-standard protocol that allows a user to grant an application limited access to a service without sharing their password. When people say “OAuth authentication,” they usually mean using OAuth 2.0 for authorization (delegated access) and pairing it with OpenID Connect (OIDC) for true user authentication (login identity). In EV charging ecosystems, OAuth is commonly used for secure access to APIs, apps, and integrations.
How OAuth works
OAuth uses access tokens instead of passwords:
– A user logs in with an identity provider (IdP) or service provider
– The user consents to grant an app certain permissions (scopes)
– The authorization server issues an access token (and sometimes a refresh token)
– The app uses the token to call APIs; the resource server validates the token
– Tokens can be short-lived, revocable, and limited in scope
Common OAuth flows
Typical OAuth 2.0 flows include:
– Authorization Code flow (often with PKCE): standard for mobile/web apps
– Client Credentials flow: machine-to-machine integrations (no user login)
– Device Authorization flow: limited-input devices (rare in EV charging UIs)
Why OAuth matters in EV charging
OAuth supports secure, scalable integrations across charging systems:
– Enables CPMS, mobile apps, and partner platforms to access APIs securely
– Supports least privilege by limiting what each integration can do
– Makes it easier to revoke compromised access without changing user passwords
– Improves auditability and governance across third-party partners (installers, analytics, billing)
– Helps protect sensitive actions (tariff changes, refunds, remote commands) alongside RBAC and MFA
Typical EV charging use cases
– Mobile app login and session management (often OAuth + OIDC)
– Partner API access for roaming, tariffs, locations, and session records
– Integrations with ERP, accounting, or property management systems
– Data exports to BI tools for mobility analytics and network KPIs
– Installer portals and commissioning tools with controlled permissions
Key concepts to understand
– Authorization server: issues tokens (often the IdP)
– Resource server: API that validates tokens and returns data
– Scopes: what the token allows (read sessions, manage users, update tariffs)
– Access token: short-lived credential used by APIs
– Refresh token: used to obtain new access tokens without re-login (handle securely)
– JWT: common token format containing signed claims (not always used)
Security best practices
– Use Authorization Code + PKCE for public clients (mobile/web)
– Use short-lived access tokens and rotate refresh tokens
– Protect refresh tokens (secure storage, never expose to browsers in unsafe ways)
– Enforce TLS everywhere and validate token audience/issuer
– Combine with RBAC for permissions and MFA for admin accounts
– Log token usage and detect anomalies (unusual IPs, excessive requests)
Related glossary terms
OpenID Connect (OIDC)
API integration
Role-based access control (RBAC)
Multi-factor authentication (MFA)
Access control
Tokenization
Data encryption
Network segmentation
Incident response plan
Secure update pipeline