Which technique is commonly used to secure sensitive information during transmission?

Encryption is a fundamental technique used to secure sensitive information during transmission. By converting data into a coded format that can only be deciphered by authorized parties, encryption ensures that even if the data is intercepted while in transit, it remains unreadable to anyone who does not possess the appropriate decryption key. This technology is essential for protecting sensitive information, such as personal data, financial details, or confidential communications, from unauthorized access and potential exploitation.

The other techniques mentioned serve different purposes in the realm of network security. Firewalls act as barriers between secure internal networks and untrusted external networks, controlling incoming and outgoing traffic but do not specifically secure data in transit. Malware scanning is designed to detect and remove malicious software from devices and networks, focusing on identifying threats rather than securing data during transmission. Spam filtering addresses the issue of unwanted or malicious email but does not protect the contents of messages during their transmission.