Techniques are provided for determining freshness of control messages in a network. At a first device that is to enter into a secure communication session with a second device, timestamp information and time window size information are sent to the second device in a control message during a first exchange between a first device and a second device. At the first device, timestamp information and time window size information are obtained from a control message received from the second device by the first device during the first exchange. At the first device, the freshness of a control message is tested based on the timestamp information of the control message during a second exchange and the time window size information received from the second device during the first exchange.