Vehicle-mounted terminal data encryption transmission method and system

The invention discloses a vehicle-mounted terminal data encryption transmission method and system, and the method comprises the steps that a vehicle-mounted terminal generates an RSA public key and an RSA private key, and transmits the generated RSA public key to a server; the server generates a random number SR; the server uses an RSA public key to encrypt a GSR mod P calculation result and sends the GSR mod P calculation result to the vehicle-mounted terminal; the vehicle-mounted terminal performs decrypting by using the RSA private key after the vehicle-mounted terminal receives the information, and calculates a secret key K; the vehicle-mounted terminal generates a vehicle-mounted random number CR; the vehicle-mounted terminal signs a vehicle-mounted random number CR generated by the vehicle-mounted terminal and a GCR mod P + RSA public key and sends the signed data to the server; the server performs signature verification by using the RSA public key and calculates a secret key K; and the vehicle-mounted