Final answer:
Symmetric ciphers commonly use the XOR operation in their processes to ensure secure encryption by providing confusion and diffusion.
Step-by-step explanation:
Most symmetric ciphers use XOR (exclusive OR) as part of their encryption and decryption process. XOR is a logical operation that outputs true only when the input values differ (one is true, the other is false). It is a fundamental operation used in various cryptographic algorithms, including stream ciphers and block ciphers, to provide confusion and diffusion, which are necessary for creating secure encryption schemes.