Enforcement Rules of the Classified National Security Information Protection Act Article 21

Classified information shall be delivered as follows:(1)For transfer of Top Secret information and Secret information within the agency, such information shall be delivered personally by the processing official.(2)For interagency transfer of Top Secret information and Secret information, such information shall be delivered by the processing official or the designated official under military or civilian escort. For interagency transfer of Confidential information, such information shall be delivered by the processing official or the designated official or sent by double-registered mail.For interagency delivery of Confidential information by the processing official or the designated official, the processing official or the designated official shall prepare for an emergency destruction of such information in case of an emergency.If classified information is not delivered personally by the processing official but by the designated official, such information shall be delivered in a sealed envelop.If classified information is transmitted through telecommunications, such information shall be secured by encryption authorized or approved by the competent government agency.
中文原文 國家機密保護法施行細則第21條
國家機密之傳遞方式如下:
一、在機關內相互傳遞,屬於絕對機密及極機密者,由承辦人員親自持送。
二、在機關外傳遞,屬於絕對機密或極機密者,由承辦人員或指定人員傳遞,必要時得派武裝人員或便衣人員護送。
屬於機密者,由承辦人員或指定人員傳遞,或以外交郵袋或雙掛號函件傳遞。
依前項第二款規定,由承辦人員或指定人員傳遞者,事先應作緊急情形之銷毀準備。
國家機密非由承辦人員親自持送傳遞者,應密封交遞。
以電子通信工具傳遞國家機密者,應以加裝政府權責主管機關核發或認可之通信、資訊保密裝備或加密技術傳遞。

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