An authentication system includes a terminal and a key authentication unit arranged in a communication peer that communicates with the terminal. The key authentication unit receives key information of the terminal carried by a user through wireless communication and performs key authentication that verifies authenticity of the key information. The authentication system further includes detectors that are arranged at different locations and detect biological information of the user and a biometric authentication unit that uses the biological information to perform biometric authentication. The authentication system further includes a controller that controls actuation of the communication peer based on a location of one of the detectors that detected the biological information, an authentication result of the key authentication, and an authentication result of the biometric authentication.