Looking at the first step of AES encryption I see that we XOR
the key with the plaintext block. Why is the actual key involved
at all, why not just use the round keys derived from the key
schedule? Does the order of a block cipher cascade (e.g. in
TrueCrypt) make a difference to the security provided, assuming
independant keys? For example: ... I'm working with a
server/client system that has securely negotiated a private key.
I need to encrypt/decrypt messages passing in both directions
which are typically between 100 bytes to 100 KB. I'm ...