V2X, vehicle to everything, covers communication between a vehicle and anything that may affect it. The two main radio approaches are DSRC, which is based on WLAN, and C-V2X, which is cellular. Both need a way to trust messages from strangers, which is why a public key infrastructure features in V2X security discussions.
The V2X family
The reference article lists these main categories:
- V2V: real time data exchange with nearby vehicles.
- V2I: communication with infrastructure such as traffic lights, lane markers and parking meters.
- V2N: communication with a wider network, such as a cellular network, including telematics and fleet management.
- V2P: communication with pedestrians, cyclists and other vulnerable road users.
It also lists vehicle to device, vehicle to grid and vehicle to cloud.
DSRC
DSRC is based on IEEE 802.11p, a WLAN technology. It supports direct communication between vehicles and with infrastructure without needing network infrastructure, and the article notes its low latency. In the US the radio technology is called WAVE and in Europe it is called ITS-G5. IEEE published the specification in 2010.
C-V2X
C-V2X is defined by 3GPP. It began with LTE in Release 14 and expanded to 5G in Release 15. It uses the PC5 interface for direct communication and the Uu interface for network communication. The article notes that 802.11p supports only direct communication.
Comparison
| Question | DSRC | C-V2X |
|---|---|---|
| Base technology | WLAN, IEEE 802.11p | Cellular, 3GPP |
| Direct vehicle to vehicle | Yes | Yes, over PC5 |
| Network communication | No | Yes, over Uu |
| Regional names | WAVE in the US, ITS-G5 in Europe | None needed |
The security questions
The radio matters less than the trust model. Whatever the technology, a receiving vehicle must decide whether to believe a message from a sender it has never met.
- Who issues credentials? Someone must vouch for each sender. The article mentions a V2X security public key infrastructure in its discussion of European regulation, and says a European platform identified PKI as a key approach in 2014.
- How are bad actors removed? Revocation must work for devices that are rarely online.
- How is privacy preserved? Messages that identify a vehicle can be used to track it. Credentials usually need to change over time.
- What does the vehicle do with a message it trusts? A trusted message that triggers braking is a safety concern, so plausibility checks matter too.
- How is the radio stack updated? It is software like any other, and falls under the update rules in UN R156.
The article does not describe a specific credential management system in the US, so check current sources before relying on a particular design.
Quick check
Is C-V2X only for network communication?
No. It also supports direct communication over the PC5 interface.
Sources
Last reviewed: 19 October 2026.
