Among the requirements for establishing a trade secret, substantial legal principles have been accumulated regarding secrecy management. With the ongoing legislative amendments aimed at strengthening trade secret protection by relaxing secrecy management requirements, the standard for effectively managing trade secrets has become increasingly clear. Furthermore, the assessment of economic utility tends to be influenced more by the determination of non-publicity than by independent criteria. Given these changes, the importance of evaluating non-publicity as a key requirement for establishing trade secrets is expected to grow.

This study analyzes various issues related to the determination of the non-public nature of trade secrets and establishes specific assessment criteria. To this end, we first examine the general concept of non-publicity in trade secrets. This is followed by an analysis of the key factors in determining non-publicity, including the identification and specification of trade secrets, burden of proof regarding non-publicity, timing and geographical scope of non-publicity determination, and extent to which non-publicity must be maintained.

The latter part of the paper discusses additional issues that have been highlighted in Supreme Court rulings but lack well-established assessment criteria. These include the scope of the entities considered in non-publicity determination, the assessment of non-publicity when some or all components of a trade secret are publicly known, and the impact of reverse engineering claims on non-publicity. Furthermore, case studies from major jurisdictions such as the United States, Japan, and Germany are analyzed to identify potential improvements in domestic trade secret protection practices.