DETECTION DEVICE, DETECTION METHOD, AND DETECTION PROGRAM

A detection device that detects an unauthorized message in an in-vehicle network mounted on a vehicle is provided with: a message acquisition unit that acquires a transmission message in the in-vehicle network; and a determination unit that performs a determination relating to an unauthorized message in the in-vehicle network by performing a determination on the transmission message acquired by the message acquisition unit, the determination unit being capable of outputting a first determination result and a second determination result, the first determination result is a determination result of whether the transmission message acquired by the message acquisition unit is the illegal message, and the second determination result is a determination result related to the transmission message. 检测装置检测搭载于车辆的车载网络中的不正当消息，其中，所述检测装置具备：消息取得部，取得所述车载网络中的发送消息；以及判定部，通过进行针对由所述消息取得部取得的所述发送消息的判定来进行与所述车载网络中的不正当消息相关的判定，所述判定部除了能够输出第一判定结果之外，还能够输出第二判定结果，所述第一判定结果是由所述消息取得部取得的所述发送消息是否为所述不正当消息的判定结果，所述第二判定结果是与所述发送消息相关的判定结果。