CyberCertPrepSecurity FundamentalsCryptography FundamentalsEASYFree question
Which logical operation is fundamental to many stream ciphers, where plaintext bits are combined with keystream bits?
- A.NOT
- B.OR
- C.AND
- D.XOR
Why D is correct
XOR (exclusive OR) is fundamental to stream ciphers because it is easily reversible: plaintext XOR keystream = ciphertext, and ciphertext XOR keystream = plaintext. This property makes it ideal for encryption and decryption using the same operation.
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