The invention discloses an OBD tamper-proof two-way
verification method, which comprises the steps of obtaining OBD equipment data and vehicle sensor data, registering to a cloud end based on the OBD equipment data, obtaining registration data, obtaining key data and non-key data according to the vehicle sensor data, symmetrically encrypting the key data by using a
session key in the registration data, and verifying the key data and the non-key data. Performing approximate
homomorphic encryption on the non-key data, obtaining a double-entropy source dynamic salt value according to the time entropy of the
ciphertext and the OBD equipment operation entropy, reversely reconstructing the dynamic salt value by the cloud according to the
timestamp and the registration data, verifying the
ciphertext structure by using the dynamic salt value and generating a random challenge containing a salt value check code, and sending the random challenge to the cloud; the equipment
verification result and the challenge value are signed and then transmitted back, the OBD equipment carries out reverse
verification on the salt value according to the signature and the equipment verification result, and the cloud generates an authority token based on the reverse verification result. According to the method, the
data authenticity and integrity of the
diagnostic equipment are guaranteed through packet
encryption, dynamic salt value generation and bidirectional identity verification of transmission data.