Which technique enhances the security of transmitted communications?

Encryption is a technique that significantly enhances the security of transmitted communications by encoding the information so that only authorized users can access and decipher it. This process transforms the original data into a format that is unreadable to anyone who lacks the necessary decryption key or algorithm. As a result, even if intercepted, the encrypted data remains secure and protected against unauthorized access or understanding.

In the context of military and defense operations, safeguarding sensitive information is paramount. Encryption ensures that operational plans, personnel data, and other critical communications cannot be easily exploited by adversaries. By employing encryption techniques, the integrity and confidentiality of information are maintained during transmission, which is essential for operational security and maintaining an advantage in various situations.

The other techniques listed do not provide the same level of security. Photocopying is related to replication of physical documents without any security enhancement. Color-coding may help organize or categorize information but does not offer protection against unauthorized access or interception. Face-to-face verification ensures authenticity of information but does not secure the communication medium itself. Therefore, encryption stands out as the primary method for securing transmitted communications effectively.