美国国防部和在国外一些政府的机要部门已开始使用美国生产的一种高级保密电话机。该电话机能将语言数字化后以不规则的顺序传送,窃听者难以将之复原。它拥有16个保密程序,并可经常改换这些程序,使保密程度进一步提高。高级保密电话机平时可作为普通多功能电话使用。插入电脑钥匙后便成为一部保密电话机。每部电话机可配上8个电脑钥匙,且可随时取消其中任何一个电脑钥匙的有效性。可通过适配器与传真机和个人电脑相连,使得传真 The U.S. Department of Defense and the confidential departments of some foreign governments have begun to use a type of advanced confidential telephone produced in the United States. The telephone can digitize the language and transmit it in an irregular order, which is difficult for eavesdroppers to recover. It has 16 confidential procedures and can often change these procedures to further increase the degree of confidentiality. High-grade confidential telephones can be used as ordinary multifunctional telephones at ordinary times. After inserting the computer key, it becomes a confidential telephone. Each telephone can be equipped with 8 computer keys, and the validity of any of the computer keys can be cancelled at any time. Can be connected to the fax machine and personal computer through the adapter, making the fax