(The fоllоwing prоvides the context for both question 2 аnd question 3) A compаny hаs software for a public-key encryption scheme that is known to be IND-CCA secure under some reasonable assumptions. But the message space for this scheme is only the set of messages up to 1 MB long. At some point they needed to encrypt messages of length more than 1MB but less than 2MB. So they decide to use the existing software to build an encryption scheme in the following way. To encrypt a message , break it into equal parts (for simplicity, let's assume that all messages have even length) and let a ciphertext be computed as