An in-vehicle encryption system for use in a vehicle comprising a plurality of vehicle subsystems. The system comprises a security ECU module that communicates with a remote cryptographic module, the security ECU module comprising a processor and a per vehicle master secret (PVMS) value stored in the security ECU module. The security ECU module uses the PVMS value to authenticate with the remote cryptographic module and to establish an external encrypted communication link with the remote cryptographic module. The system further comprises a first subsystem ECU module that generates a first globally unique identifier (GUID) and a second subsystem ECU module that generates a second GUID. The security ECU module uses the first GUID value to establish a first encrypted communication link with the first subsystem ECU module.