Classified National Security Information Protection Act Article 2

The term "classified national security information" referred to in this Act means information that is owned by, or under the control of the Government of the Republic of China and that has been determined pursuant to this Act to require protection against unauthorized disclosure, and that is so designated according to its level of classification for the purpose of safeguarding the national security or national interest.
中文原文 國家機密保護法第2條
本法所稱國家機密,指為確保國家安全或利益而有保密之必要,對政府機關持有或保管之資訊,經依本法核定機密等級者。

English translation for reference only; the Chinese text prevails. Not legal advice.