Why is it important to encrypt the transmission of cardholder data across public networks?

• A. Because encryption makes data unreadable to unauthorized observers during transmission.
• B. Because encryption adds more cost.
• C. Because encryption protects data in transit from being read if intercepted.
• D. Because it eliminates all threats.

Answer: (C)

Encrypting cardholder data as it travels across public networks is about preserving confidentiality during transit. Public networks are easy to eavesdrop on, so if data were sent in cleartext, an attacker could read sensitive information like card numbers and other details. Encryption turns that data into ciphertext, which can’t be understood without the decryption keys, so intercepted traffic remains meaningless to anyone who shouldn’t see it. This directly reduces the risk of data exposure for customers and helps meet compliance requirements for protecting payment information. It’s true that encryption doesn’t remove every threat or make data invulnerable, and it can add some cost, but the primary benefit is preventing readable data from being captured in transit, which is the main reason for encrypting data across public networks.