I am studying cryptography and various block cipher modes of operation.
Suppose I changed one bit in the last block of the message. Wouldn't that imply no change in all encrypted blocks except for the last one?
At least based on the description of how various modes work (CBC, OFB, etc), I don't see why that wouldn't be the case.
However, if that is true, then the encryption mode lacks the avalanche effect property, doesn't it? A single bit change in
any place should completely change the encrypted text.
Could someone correct my observation, or explain why lack of avalanche effect is not dangerous?