Ciphers in CBC mode reveal place of change in plaintext Theoretically, when using a symmetric block cipher in CBC mode, the current block is dependent on the previous block. Suppose one plaintext is encrypted using CBC, and then one bit of it is changed, let's say somewhere in the middle. Then the new ciphertext will change from the middle onward. Would it be better if I used CBC like this?


encrypt plaintext
reverse the ciphertext 
continue encrypting (now from finish to start)


That would ensure that one modification to the plain text will change the entire new ciphertext. Right?
Your problem is that if you encrypt two messages which start the same (and change at some point later on) the beginning of the ciphertext will be the same in CBC mode when using the same IV.

Normally you should change the IV every time you encrypt a new message. This is precisely what the IV is meant for - achieving IND-CPA (semantic) security which prevents an attacker from detecting where the the message was changed. Once you do this, your concerns go away, since even two similar messages (say, an old document, and a newer, slightly revised one) will be encrypted with completely different IV's, and hence their ciphertext will be unrelated. And you don't need a two-pass scheme anymore!