Same Encryption Algorithm: Obtaining Encrypted Messages
Question
In which of the following cryptographic attacking techniques does an attacker obtain encrypted messages that have been encrypted using the same encryption algorithm?
Answers
Explanations
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A. B. C. D.B.
The answer to the question is "B. Ciphertext only attack".
To understand why, let's first define the four cryptographic attacking techniques mentioned in the question:
Chosen plaintext attack: In this type of attack, the attacker has the ability to choose the plaintext to be encrypted and obtain the corresponding ciphertext. The attacker then uses this information to deduce the encryption key.
Ciphertext only attack: In this type of attack, the attacker has access to only the encrypted ciphertext but not the corresponding plaintext. The attacker attempts to deduce the encryption key solely by analyzing the ciphertext.
Chosen ciphertext attack: In this type of attack, the attacker has the ability to choose ciphertext and obtain the corresponding plaintext. The attacker then uses this information to deduce the encryption key.
Known plaintext attack: In this type of attack, the attacker has access to both the plaintext and the corresponding ciphertext. The attacker uses this information to deduce the encryption key.
Given the above definitions, we can see that a ciphertext only attack is the one where an attacker obtains encrypted messages that have been encrypted using the same encryption algorithm. In this scenario, the attacker only has access to the ciphertext and has to rely solely on analyzing the ciphertext to deduce the encryption key.
In contrast, a chosen plaintext attack would require the attacker to have the ability to choose the plaintext to be encrypted, which is not the case in this scenario. A chosen ciphertext attack would require the attacker to have the ability to choose ciphertext and obtain the corresponding plaintext, which again is not the case in this scenario. Finally, a known plaintext attack would require the attacker to have access to both the plaintext and the corresponding ciphertext, which is also not the case in this scenario.
Therefore, the correct answer to the question is B. Ciphertext only attack.
