Abstract: “this paper discusses the Trojan defense, a common question on who really did it. In order to prove who did this post on SNS means we want to connect a specific internet character with a real person in the world. Actually, the present technology only can prove the issued post done by a specific IP address. Prosecutors need circumstance evidences to support their claims and connect to the defendant. Thus, this paper first will explain the background of the Trojan defense, such as the definition, characteristics and functions of the Trojan. Then it discusses how to handle the Trojan defense in technical and legal approaches, and concludes how the legal system represents or actually constructs the past fact.”

Keywords: Trojan Defense, Judging by Circumstantial Evidence, Reinforcing Evidence, The Process of Judging the Trojan Defense, Connect the Virtual to a Real World