It appears that the operations performed on the left and right alphabets are linear given the output above. As such, Chaocipher is vulnerable to known-plaintext attacks.
But, given that the full keyspace is not realized during encryption, we should also be able to launch a key recovery attack and recover both alphabets if enough ciphertext is provided.
Which means, a ciphertext-only attack seems within reach. Famous last words of course, but I think this one is very practical.
Aaron Toponce ⚛️:debian: /
npub1t9…t8529
2024-05-23 19:14:21
in reply to nevent1q…zwwx
Author Public Key
npub1t9cz9v7zph5jvadd8rjfp25msrx6r0hdxnsyfmx88k8qp3pvv04szt8529Published at
2024-05-23 19:14:21Event JSON
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"content": "It appears that the operations performed on the left and right alphabets are linear given the output above. As such, Chaocipher is vulnerable to known-plaintext attacks.\n\nBut, given that the full keyspace is not realized during encryption, we should also be able to launch a key recovery attack and recover both alphabets if enough ciphertext is provided.\n\nWhich means, a ciphertext-only attack seems within reach. Famous last words of course, but I think this one is very practical.",
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