ITS Cybersecurity Glossary¶

Authorization Authority (AA)¶

In European C-ITS, the component that issues short-term Authorization Tickets to ITS stations for signing messages.

Authorization Ticket (AT)¶

A short-lived certificate in the European CCMS used to sign V2X messages while protecting sender privacy.

Certificate Trust List (CTL)¶

A list of trusted Root Certificate Authorities and security authorities used to verify which certificates a system accepts.

Cooperative ITS Credential Management System (CCMS)¶

The European system for managing certificates, trust lists, and permissions for ITS stations.

European Certificate Trust List (ECTL)¶

The signed electronic version of a trust list used in European deployments to distribute trusted root and authority information to devices.

Enrolment Authority (EA)¶

In European C-ITS, the authority that issues Enrolment Credentials proving a device’s legitimacy.

Enrolment Credential (EC)¶

A long-term certificate proving that a device is approved to request operational certificates.

Hardware Security Module (HSM)¶

A dedicated hardware component used to securely generate, store, and use cryptographic keys; provides strong protection against key theft or tampering.

Intelligent Transport System Application Identifier (ITS-AID)¶

Used to uniquely identify ITS application objects.

Lateral Movement¶

An attacker technique where access gained on one device or network segment is used to move to other connected systems, increasing the impact of a breach.

Man-in-the-Middle Attack¶

A threat where an attacker secretly intercepts and possibly alters communication between two parties who believe they are communicating directly with each other.

Misbehaviour Detection¶

A set of processes and services that identify and respond to devices that send invalid or malicious messages.

Onboard Unit (OBU)¶

An in-vehicle device that communicates with other vehicles and roadside equipment using secure V2X messages.

Provider Service Identifier (PSID)¶

An identifier in certificates that defines which ITS applications a device is authorized to use.

Pseudonym Certificate¶

A short-lived certificate in the SCMS that allows vehicles to sign messages without exposing a permanent identity.

Root Certificate Authority (Root CA)¶

The highest trust anchor in a PKI that signs subordinate certificates.

Roadside Unit (RSU)¶

A field device mounted along the roadway that exchanges secure messages with vehicles and backend systems.

Security Credential Management System (SCMS)¶

The North American system for managing V2X certificates, permissions, trust lists, and misbehaviour response.

Service Specific Permission (SSP)¶

A field in a certificate that provides detailed constraints on what actions a device may perform within an application.

Trusted Platform Module (TPM)¶

A secure hardware chip embedded in a device that stores keys and measurements used for secure boot and attestation; similar in purpose to an HSM but typically built-in.