image Intercepting Communications

Intercepting Your Communications


Overview and Countermeasures

Many foreign governments, including friendly countries allied with the United States, have large programs to collect economic, political and military intelligence by intercepting U.S. communications.

bullet  Most U.S. long distance telephone and fax communications goes via the air waves -- and any signals in the air can be and frequently are intercepted.

Many of the technological advances designed for our convenience can easily be used against us. Cellular telephones are especially vulnerable, but cordless phones, e-mail, answering machines and voice mail can all be exploited in various ways.

Are you a potential target? If eavesdropping on anything you say or write could increase someone else's wealth or influence, then the answer must be yes, you are a potential target.

Some countries now focus their communications intercept programs against the U.S. on collection of competitive economic and industrial intelligence in addition to traditional military and political targets. Targets now include information such as marketing plans, customer lists, financial data, contract negotiations, research and development, and production technology for new products. The foreign collectors of this information typically pass it to companies in their country to foster national economic development. U.S. intelligence agencies are prohibited by law from sharing acquired foreign economic and industrial information with domestic U.S. commercial organizations. This can and often does put American companies at a distinct disadvantage.


In most cases, there is no way to know whether an individual communication is being monitored. Because it is so easy to monitor communications and happens so often, it is best to assume that any communication which contains information of great potential value to another person, organization, or country may be monitored. There are only two ways to counter interception of telephone and fax communications:

  • Do not discuss or even allude indirectly to sensitive subjects over the telephone or fax.

  • If you must use telephone or fax, encrypt all sensitive communications.

Sensitive information should not be discussed by phone or sent by fax on any unencrypted line. Long distance communications and cellular phone calls are especially vulnerable to monitoring as they go through the airwaves. Many people think they are being secure by using double-talk, or talking around a sensitive subject, when using the phone. This may fool a casual eavesdropper who hears only that one conversation, but it is generally ineffective when someone is monitoring all your calls.

To reduce the chances of your phone number getting on the target list, avoid key words or phrases that intelligence collectors may use in automated searches to identify conversations of potential intelligence interest. Examples are organization names, project code names, product names, names of senior personnel, and labels such as sensitive and company confidential.

Encryption works. The growth of wireless communications has prompted a comparable growth in encryption to thwart the many eavesdroppers. Within the U.S. government and defense industry, the secure telephone unit (STU-III) provides a secure means for discussing classified information over the telephone.

bullet  If you have a STU-III secure telephone, use it, but remember that even the STU-III depends upon strict telephone security discipline. A defector from one of the foreign intelligence services that monitor U.S. communications reports that STU-III encryption is unbreakable. However, he also advised that the chitchat that occurs before the STU-III is switched to secure mode and after it is switched off of secure mode is a bonanza of valuable information.

Communications monitors can identify STU-III lines, so these phone numbers are obvious targets. Therefore, a STU-III line being used in non-secure mode may be more likely to be monitored than another line that never carries encrypted communications.

Related Topics: Using the STU-III, Who's Doing What to Whom?, Overseas Communications.





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