Abstract: A blockchain-based interconnected vehicle authentication system and method. During message signature process, a registered vehicle verifies a driver, and broadcasts a message. During a message verification process, a registered vehicle checks the message authentication code from a received message based on the system key, and verifies the message based on a public key of a sender of the message. During a block generation and verification process, the first local trust authority broadcasts a block, and share the block to the second local trust authorities after the block passes verification. During a block confirmation process, second local trust authority makes confirmation with regard to the block and send a confirmation result to the root trust authority, to allow the root trust authority link the block into the blockchain in response to receiving confirmation results from second local trust authorities in a quantity exceeding a predetermined number.