What is the key advantage of using encryption in communication systems?

Using encryption in communication systems primarily serves to prevent unauthorized listening, which is a crucial aspect of maintaining the confidentiality and integrity of sensitive information. By converting plaintext into ciphertext, encryption ensures that even if the data is intercepted during transmission, it remains unreadable to unauthorized parties. This is particularly important in fields like medical logistics, where sensitive patient data and confidential information about supplies and distribution are communicated.

The importance of this security measure cannot be overstated, as it protects against eavesdropping, data breaches, and potential misuse of information. While the other options may contribute to various aspects of telecommunications—like saving bandwidth, improving signal quality, or increasing transmission speed—they do not directly correlate to the primary purpose of encryption. Thus, the most significant and distinguishing advantage of encryption in communication systems is its role in safeguarding against unauthorized access.