Physically secured authorization for utility applications
View Patent ↗To provide overall security to a utility management system, critical command and control messages that are issued to components of the system are explicitly approved by a secure authority. The explicit approval authenticates the requested action and authorizes the performance of the specific action indicated in a message. Key components of the utility management and control system that are associated with access control are placed in a physical bunker. With this approach, it only becomes necessary to bunker those subsystems that are responsible for approving network actions. Other management modules can remain outside the bunker, thereby avoiding the need to partition them into bunkered and non-bunkered components. Access to critical components of each of the non-bunkered subsystems is controlled through the bunkered approval system.
1. A method for controlling devices in a utility network, comprising:
generating, by a data center configured to communicate with the devices in the utility network, a command for an operation to be carried out by a device in the utility network;
forwarding the command, by the data center, to a hardware security module of a physical bunker comprised in the data center, the physical bunker having access restricted thereto;
within the hardware security module, executing the following functions:
performing a cryptographic service on the command that enables a recipient of the command, upon which the service has been performed, to authenticate the command as one that the recipient is permitted to execute,
counting the number of cryptographic services performed by the hardware security module in a specified time period, and
if the counted number of cryptographic services performed within the specified time period exceeds a threshold limit, terminating the performance of further cryptographic services on received commands; and
by the data center, transmitting the command, upon which the cryptographic service has been performed, to the device in the utility network to carry out the operation.
2. The method of claim 1 , wherein the counting of the number of cryptographic services is performed over a sliding time window of the specified period.
3. The method of claim 2 , wherein the counting of the number of cryptographic services is performed with respect to a plurality of sliding time windows, each of which is associated with a different respective length of time and threshold limit.
4. The method of claim 1 , wherein the cryptographic service is encryption of the command.
5. The method of claim 1 , wherein the cryptographic service is signing the command.
6. The method of claim 1 , further including the step of generating a warning when the counted number of cryptographic services reaches a predetermined value less than the threshold limit.
7. The method of claim 1 , wherein the hardware security module comprises a plurality of slots, and wherein the functions are executed in one of the slots.
8. The method of claim 7 , wherein the functions are also executed in a second slot, using a different respective threshold limit.
9. The method of claim 1 , wherein the device is configured to determine whether a received command is authorized by using a public key associated with the cryptographic service.
10. A back office system for controlling devices in a utility network, the back office system comprising:
a data center configured to communicate with devices in the utility network; and
a physical bunker comprised in the data center, the physical bunker having access restricted thereto, and the physical bunker comprising a hardware security module,
wherein the data center is configured to generate a command for an operation to be carried out by a device in the utility network, and forward the command to a hardware security module,
wherein the hardware security module is configured to:
perform a cryptographic service on the command that enables a recipient of the command, upon which the service has been performed, to authenticate the command as one that the recipient is permitted to execute,
count the number of cryptographic services performed by the hardware security module in a specified time period, and
if the counted number of cryptographic services performed within the specified time period exceeds a threshold limit, terminate the performance of further cryptographic services on received commands, and
wherein the data center is configured to transmit the command, upon which the cryptographic service has been performed, to the device in the utility network to carry out the operation.
11. The back office system of claim 10 , wherein the hardware security module is configured to count the number of cryptographic services over a sliding time window of the specified period.
12. The back office system of claim 11 , wherein the hardware security module is configured to count the number of cryptographic services with respect to a plurality of sliding time windows, each of which is associated with a different respective length of time and threshold limit.
13. The back office system of claim 10 , wherein the cryptographic service is encryption of the command.
14. The back office system of claim 10 , wherein the cryptographic service is signing the command.
15. The back office system of claim 10 , wherein the hardware security module is configured to generate a warning when the counted number of cryptographic services reaches a predetermined value less than the threshold limit.
16. The back office system of claim 10 , wherein the hardware security module comprises a plurality of slots, and wherein the hardware security module is configured to execute the functions in one of the slots.
17. The back office system of claim 16 , wherein the hardware security module is configured to execute the functions in a second slot, using a different respective threshold limit.
18. The back office system of claim 10 , wherein the device is configured to determine whether a received command is authorized by using a public key associated with the cryptographic service.