CCCrypt decrypting in AES CBC works even without IV

Question

I have a confusing problem, where decrypting a file which was encrypted using CCCrypt\'s AES-CBC mode with a randomized, 16byte IV produces the exact same output whether I p

Answer 1

You can read the correct answer here: http://www.remote-exploit.org/archives/2012/01/09/the_apple_idioten_vektor_iv/

Apple made an error in their Crypto Library that assumes that if the IV vector is not provided they automatically set the IV to a zero vector instead of returning an error. An IV should always be provided to ensure the best security and Apple should not be doing their zero assumption as it greatly weakens security and makes it vulnerable to attacks.