My question is related to another question in Cryptography about TLS 1.1 and 1.2. I have read both RFC 2246 The TLS Protocol Version 1.0 and RFC 4346 The TLS Protocol Version 1.1. What I know is that one of their differences is TLS 1.0 uses implicit initialization IV (from the key_block) and TLS 1.1 uses explicit IV, which can be generated with either of the three ways specified in Section 188.8.131.52 of RFC 4346. In the same section, it is stated that
The decryption operation for all three alternatives is the same. The receiver decrypts the entire GenericBlockCipher structure and then discards the first cipher block, corresponding to the IV component.
The above statement is not clear to me. For example, if I have an encrypted message consisting of blocks
[Encrypted Block 1], [Encrypted Block 2], ..., [Encrypted Block n], does that mean that when decrypting, I should discard
[Encrypted Block 1]from the other blocks and decrypt
[Encrypted Block 2], ..., [Encrypted Block n]using
[Encrypted Block 1]as IV?
- Is the above example correct? If not, how can the IV to be used for decryption be determined?
- Is the decryption for TLS 1.1 the same as TLS 1.2?