n.密码电话学
80. Telephone communications which are protected against compromise through use of an approved ciphony system . 通过使用有效的密码电话系统，保护电话通信不被泄漏。
12. Telephone communications which are protected against compromise through use of an approved ciphony system . 通过使用有效的密码电话系统，保护电话通信不被泄漏。
57. Telephone communications which are protected against compromise through use of an approved ciphony system . 通过使用有效的密码电话系统，保护电话通信不被泄漏。
communications which are protected against compromise through use of an approved ciphony system . 通过使用有效的密码电话系统，保护电话通信不被泄漏。
