Many wireless technologies make use of one simple technology to prevent eavesdropping on the signal. What is it?

The correct answer is encryption. Encryption is a fundamental technology employed in various wireless communications to protect data from unauthorized access and eavesdropping. It involves converting the original data into a coded format that can only be read by someone who possesses the appropriate decryption key. This ensures that even if an attacker intercepts the transmission, they would not be able to understand the information without the corresponding decryption mechanism.

While frequency hopping is a technique that can enhance the security of a wireless transmission by rapidly switching frequencies, it does not directly encrypt the data being transmitted. Instead, it provides a layer of protection by making it more difficult for eavesdroppers to lock onto the specific frequency being used at any moment. Signal jamming, on the other hand, disrupts communication altogether rather than securing it, and Time Division Multiple Access is a method of channel access that doesn't inherently include security features against eavesdropping. Therefore, encryption remains the key technology used specifically for preventing eavesdropping in wireless communications.