Design and Implementation of the communication protocol for efficient CBC mode processing in IPSec

The IV (initial vector) used in CBC mode must be varied per message, must not be used arbitrarily by attackers, and must be created randomly. To meet these requirements, IV encrypted before a message is sent. Note, however, that this method requires additional steps for IV encryption before sending a message and decryption by the receiver. This paper proposed the method that does not require IV encryption/decryption and developed the lightweight protocol and security API specification based on the proposed method. As a result of the experiment, system performance improvement can be achieved. In an environment with small-sized packet data, in particular, greater system performance improvement can be achieved. Moreover, since small-sized random numbers are sent without the entire IV, sending overhead can be reduced considerably compared to the existing methods