13 lines
662 B
Plaintext
13 lines
662 B
Plaintext
In encryption, when Cipher Block Chaining (CBC) is used, the Initialization Vector (IV) must be random and unpredictable. Otherwise, the encrypted value is vulnerable to crypto-analysis attacks such as the "Chosen-Plaintext Attack".
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An IV value should be associated to one, and only one encryption cycle, because the IV's purpose is to ensure that the same plaintext encrypted twice will yield two different ciphertexts.
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To that end, IV's should be:
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* random
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* unpredictable
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* publishable (IVs are frequently published)
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* authenticated, along with the ciphertext, with a Message Authentication Code (MAC)
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This rule raises an issue when the IV is hard-coded.
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