Complexity of ECB and OFB What is the complexity of ECB in terms of Time and Memory?

and also in OFB? I can't find it in the internet, so I decided to ask it in here.
Well, assuming that you have a fixed block cipher (that is, you don't change the block cipher as the length of the message increases), then given a message of length $N$:


Both ECB and OFB take $O(N)$ time for both encryption and decryption.
Both ECB and OFB take $O(1)$ space in addition to the space to hold the encrypted/decrypted message (which is $O(N)$).