312-50V11 · Question #552
A hacker was able to sniff packets on a company's wireless network. The following information was discovered: The Key 10110010 01001011 The Cyphertext 01100101 01011010 Using the Exlcusive OR, what wa
The correct answer is B. 11010111 00010001. XOR decryption reverses XOR encryption by applying the same key to the ciphertext - because Ciphertext XOR Key equals the original Plaintext.
Question
A hacker was able to sniff packets on a company's wireless network. The following information was discovered:
The Key 10110010 01001011 The Cyphertext 01100101 01011010 Using the Exlcusive OR, what was the original message?
Options
- A00101000 11101110
- B11010111 00010001
- C00001101 10100100
- D11110010 01011011
How the community answered
(21 responses)- A5% (1)
- B76% (16)
- C14% (3)
- D5% (1)
Why each option
XOR decryption reverses XOR encryption by applying the same key to the ciphertext - because Ciphertext XOR Key equals the original Plaintext.
00101000 11101110 is not the bitwise XOR result of the given key (10110010 01001011) and ciphertext (01100101 01011010).
XOR encryption follows the identity: Plaintext XOR Key = Ciphertext, which means Ciphertext XOR Key = Plaintext. XORing the first bytes (10110010 XOR 01100101) produces 11010111, and XORing the second bytes (01001011 XOR 01011010) produces 00010001, yielding the original message 11010111 00010001.
00001101 10100100 is not the bitwise XOR result of the given key and ciphertext values.
11110010 01011011 is not the bitwise XOR result of the given key and ciphertext values.
Concept tested: XOR stream cipher decryption calculation
Source: https://csrc.nist.gov/publications/detail/sp/800-175b/rev-1/final
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