I wanted to know if my understanding is correct! I have been reading up on aes encryption and modes(specifically CTR and CBC) and it took me sometime to understand the concept of IV. If the IV is generated randomly then:
In CBC mode typically IV is prepended or appended after the encryption,So the first block of the cipher text is decrypted using this first block of data recieved which is the IV and from there on the previous cipher block is the IV for the next block.
I am not sure about the practice in CTR mode but there is a counter(or nonce) that increments the IV for each block for decryption adn encryption.
If the IV is generated value then well both parties need to agree on how it is generated. And using a constant IV is not really recommended to use a fixed IV for any mode.
I also want to know, what other standard practices are in use to communicate the IV in between two parties in different AES modes?