Systems, methods, and software can be used to provide secure inter-vehicle data communications. In some aspects, a method, comprising: receiving, at a security server and from a hardware security processor connected to a system bus of a vehicle, security confidence data of the vehicle, wherein the security confidence data include at least one of version information of a software code executing on a component of the vehicle, diagnostic data information of the vehicle, or data traffic pattern information of the vehicle; determining, at the security server, a security confidence score of the vehicle; receiving, at the security server, a query from a different vehicle; and in response to the query, transmitting the confidence score of the vehicle to the different vehicle.