Patent attributes
Technology is described for using a first key to secure communications over a network link between a server and a client. A second key may be identified. A first message may indicate the server may receive data from the client using the second key but not to transmit data to the client using the second key, and that the first key is valid for sending and receiving data between the server and the client. A second message may indicate that the client may send and receive data with the server using the second key, and that the client may receive data from the server using the first key but not transmit data to the server using the first key. A third message may indicate that the server may send and receive data with the client using the second key, and that the first key is invalid for sending and receiving data between the server and the client.