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seen Jun 19 at 19:59

Jun
19
comment What algorithm would give the shortest ciphertext for very short plaintexts?
It is also subject to frequency analysis which doesn't even require a plaintext / ciphertext pair. It seems equivalent to a Vernam cipher.
Jun
19
comment What algorithm would give the shortest ciphertext for very short plaintexts?
However, this is extremely insecure... the key can be easily recovered by an attacker that knows the ciphertext for a single plaintext
Jun
11
comment Why does CBC decryption with a wrong IV still give readable results?
More exactly... in case 1: the plain text is encrypted using IV = E(R), decryption encrypts R as block 1 then uses E(R) for block 2. In case 2: the algorithm is run first on IV (to encrypt it) giving E(R) so the plaintext is encrypted using E(E(R)). Since E(R) is written as the first block of the file, when decrypting, E(E(R)) ends up being used for the the plaintext, thus correct decrypting.
Jun
11
comment Why does CBC decryption with a wrong IV still give readable results?
Just kind of disconcerting to have a serious bug in my code... in 2 different ways no less... and have it still kind of work :)
Jun
11
comment Why does CBC decryption with a wrong IV still give readable results?
Oh I get it... it doesn't really matter what IV was put into the first block, because whatever it is... either R or E(R)... the same IV will be used in decrypting block 2 that was used in encrypting block 2... so the decryption should work in either case... right?
Jun
11
comment Why does CBC decryption with a wrong IV still give readable results?
I still don't understand how it would decrypt the 2nd block correctly no matter whether the IV is encrypted or not... it seems that my 'Case 1' or 'Case 2' should work... but not both!
Jun
11
comment Why does CBC decryption with a wrong IV still give readable results?
Second case... it is encrypting IV using a random value as the IV.
Jun
11
comment Why does CBC decryption with a wrong IV still give readable results?
I used CBC......
Jun
11
comment What algorithm would give the shortest ciphertext for very short plaintexts?
What about AES with a fixed IV?