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2

Aren't $IV_1$ and $IV_2$ public in TLS 1.2 as well? $IV_1$ certainly is (as that's just the ciphertext block in front of the block we're attacking); however the IV that the TLS 1.2 sender will use for the next message ($IV_2$) is not. In fact, the sender might not know it yet, as it might not have not picked it yet. But doesn't this mean that BEAST ...

2

That's a lot of questions, I'll try and answer in order. A hash or message digest alone is not secure because anybody can calculate and thus substitute a hash value. If you (correctly) add a key to the mix then you get a HMAC, which can be used. Nowadays often a HMAC is used, or an authenticated mode of authentication such as GCM, CCM (for packet ...

0

First, you have to know what padding you are using. In the padding, you will find the padding length. Second, you should set the padding type in the library. Third, removing and validating and using padding is tricky and can lead to some padding oracle attacks. In essential, the attacker modifies a block, which is likely to result in wrong padding and a ...

8

The modern trend for encryption-only modes is clearly CTR, which has a number of advantages over other modes: no padding is needed (contrary to CBC); the computationally-intensive part can be efficiently performed with the IV (and key) only, before the plaintext or ciphertext is available (contrary to CBC, CFB); the computationally-intensive part can be ...

1

For question (1): This page gives some hints on IVs and CBC: https://defuse.ca/cbcmodeiv.htm I copy-paste the part about IVs "predictability" Chosen-Plaintext Attacks Randomness is not enough, though. IVs have to be unpredictable, too[2]. Suppose there is a CBC-mode encryption system that selects a random IV, publishes it, asks the user ...

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