Patent ID: 8117273

Claim:
An instant messaging security device configured for intercepting and encrypting unencrypted instant messages routed for transmission from a first user device to an instant message server through a network and being further configured for intercepting and decrypting encrypted instant messages routed for transmission from the instant message server to the first user device through the network, the instant messaging security device comprising: a network interface configured to communicate with the first user device and the network to intercept unencrypted instant messages routed for transmission from the first user device to the instant message server through the network, to transmit discovery instant messages, and to intercept encrypted instant messages routed for transmission from the instant message server to the first user device through the network; a memory storing instructions; and a processing component coupled to the network interface and the memory, the processing component, according to the stored instructions, configured to: intercept an unencrypted instant message from the first user device addressed to a second user device through an instant message server; transmit, in response to intercepting the unencrypted instant message, a discovery instant message addressed to the second user device, the discovery instant message including data indicating that the instant messaging security device is capable of encrypting instant message data according to a security protocol; determine, in response to the discovery instant message, whether a response to the discovery instant message is received from a responding instant messaging security device; in response to determining a response to the discovery instant message is not received, allow transmission of the unencrypted instant message to the second user device and allow transmission of an unencrypted instant message from the second user device to the first user device; in response to determining a response to the discovery instant message is received: transmit a first negotiation instant message to the responding instant messaging security device, the first negotiation instant message including data for negotiating an encryption technique with the responding instant messaging security device to encrypt unencrypted instant messages from the first user device to the second user device and to decrypt encrypted instant messages from the second user device to the first user device; receive a second negotiation instant message from the responding instant messaging security device, the second negotiation instant message including data specifying the encryption technique; encrypt the unencrypted instant message from the first user device using the encryption technique; transmit the encrypted instant message to the second user device; decrypt encrypted instant messages received from the responding instant messaging security device and addressed to the first user device; and transmit the unencrypted instant message from the second user device to the first user device.