In 1898, Nikola Tesla demonstrated a radio controlled boat in Madison Square Garden that allowed secure communication between transmitter and receiver See more

A further category, which touches upon secure communication, is software intended to take advantage of security openings at the end-points. This software category includes See more

Bugging
The placing covertly of monitoring and/or transmission devices either within the communication device, or in the premises concerned.
Computers (general)
Any security … See more

Several secure communications networks, which were predominantly used by criminals, have been shut down by law enforcement … See more

Types of security
Security can be broadly categorized under the following headings, with examples:
• Hiding the content or nature of a communication
• Hiding the parties to a communication – preventing … See more

Encryption
Encryption is a method in which data is rendered hard to read by an unauthorized party. Since encryption methods are created to be extremely hard to break, many communication methods either use deliberately weaker … See more

Cellphones
Cellphones can easily be obtained, but are also easily traced and "tapped". There is no (or only limited) … See more