Patent ID: 7721321
Filing Date: 2010-05-18
Classification: H04L,Y04S

Abstract:
1. A method for reducing communication system downtime when enabling cryptographic operation of a cryptographic system of the communication system upon receipt of a command to enable cryptographic operation, the cryptographic system including a first cryptographic device coupled to a plurality of second cryptographic devices via a communication network of the communication system, the method comprising the steps of: causing a first cryptographic mode of the first cryptographic device and the plurality of second cryptographic devices to be suspended; the first cryptographic device sequentially determining a readiness state of each of the plurality of second cryptographic devices, wherein a first readiness state indicates said first cryptographic device and one of said plurality of second cryptographic devices is able to participate in synchronized cryptographic communications and a second readiness state indicates said first cryptographic device and one of said plurality of second cryptographic devices are not able to participate in synchronized cryptographic communications; causing the first cryptographic device and each of the plurality of second cryptographic devices to synchronously switch to operate in a second cryptographic mode if each of the plurality of second cryptographic devices are determined to have first readiness state, wherein the first cryptographic mode is a pass-through mode rendering said first cryptographic device and one of said plurality of second cryptographic devices transparent to the communications network, and the second cryptographic mode is a secure mode enabling cryptographic operation on data transmitted via the communication network; wherein the step of causing the first cryptographic mode of the first cryptographic device and the plurality of second cryptographic devices to be suspended comprises: detecting receipt of a first command to synchronously enable said second cryptographic mode operation of the first cryptographic device and the plurality of second cryptographic devices; and in response to detecting receipt of the first command, broadcasting a number of second commands to the first cryptographic device and the plurality of second cryptographic devices to suspend the first cryptographic mode and switch to the second cryptographic mode wherein the step of sequentially determining the readiness state of each of the plurality of second cryptographic devices comprises: (a) transmitting a third command to one of the plurality of second cryptographic devices that has not transmitted a second message, the third command requesting a status of the one of the plurality of second cryptographic devices, the second message including an indication of the first state; (b) detecting receipt of a first message from the one of the plurality of second cryptographic devices, the first message including a challenge value; (c) encrypting the challenge value with an encryption key of the first cryptographic device to form an encrypted challenge value; (d) transmitting a fourth command to the one of the plurality of second cryptographic devices, the fourth command including the encrypted challenge value; (e) detecting receipt of the second message from the one of the plurality of second cryptographic devices, receipt of the second message indicating successful decryption and authentication of the encrypted challenge value; and (f) iteratively repeating steps (a)-(e) until detecting receipt of the second message from each of the plurality of second cryptographic devices.