비밀의 시간적 범위에 관한 사법(私法)상 문제 -법경제학적 요건을 중심으로-

Like a legal right, a secrecy is not unconditional and eternal. A fact that was a secret to someone in the past can lose its benefit of protection by the elapse of time. So it's not a secret anymore. On the other hand, a fact that was not a secret in the past can acquire the value of secret protection in the time to come. Besides the opposite can have a benefit of information to a protected secret in some cases. This is effective not only a view of static time but also a view of flowing time. In this way whether a secrecy exists or not is the premise of right and obligation change by the time. And it has a contradictional benefit. So, it is important to decide a requirement of secrecy existence and inexistence. First, it could be possible to examine extinctive prescription and clausula rebus sic stantibus of the Civil Law. But through these, it's difficult to solve because a secrecy has special feature in comparison with a property right. And, the right to be forgotten that is raised recently from EU and US can be applied to this problem. But this also has a limit on the moment that the right could be acquired and used. Therefore, approaching in law and economics can be meaningful. Using a concept of Utility can make allocative efficiency of the right. Cost-benefit comparison is not suitable for private law affected by the principle of Privatautonomie. Because cost-benefit comparison has extrinsic compulsion. But Utility has personal spontaneity and subjective intention, so it makes trading of rights possible. And this is suitable for the Privatautonomie. So, it can be conclusive that changing and comparing Utility makes the point of optimum. This Pareto optimum can decide a requirement of secrecy existence or inexistence as time passed.