Scalable replay counters for network security
First Claim
1. A method, comprising:
- maintaining, at a processor of a computing device configured to operate as an authenticator in a communication network, a persistent authenticator epoch value that the authenticator increments each time the computing device reboots;
maintaining, at the authenticator, a persistent per-supplicant value for each supplicant of the authenticator, each per-supplicant value set to a current value of the authenticator epoch value each time the corresponding supplicant establishes a new security association with the authenticator, wherein maintaining the persistent per-supplicant value for each supplicant comprises storing each persistent per-supplicant value with a corresponding pairwise temporal key (PTK) stored during each new security association; and
transmitting at least one message from the authenticator to a particular supplicant, each message comprising a per-supplicant replay counter having a security association epoch counter and a message counter specific to the particular supplicant, wherein the security association epoch counter for each message is set as a difference between the authenticator epoch value and the per-supplicant value for the particular supplicant when the message is communicated, wherein the authenticator resets the security association epoch counter each time the corresponding supplicant establishes a new security association with the authenticator and the authenticator increments the security association epoch counter each time the authenticator reboots, and wherein the message counter is incremented for each message communicated;
wherein the authenticator increments the security association epoch counter for the particular supplicant in response to the message counter rolling over; and
wherein the authenticator must establish a new security association with the particular supplicant if the security association epoch counter rolls over.
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Accused Products
Abstract
In one embodiment, an authenticator in a communication network maintains a persistent authenticator epoch value that increments each time the authenticator restarts. The authenticator also maintains a persistent per-supplicant value for each supplicant of the authenticator, each per-supplicant value set to a current value of the authenticator epoch value each time the corresponding supplicant establishes a new security association with the authenticator. To communicate messages from the authenticator to a particular supplicant, each message uses a per-supplicant replay counter having a security association epoch counter and a message counter specific to the particular supplicant. In particular, the security association epoch counter for each message is set as a difference between the authenticator epoch value and the per-supplicant value for the particular supplicant when the message is communicated, while the message counter is incremented for each message communicated.
52 Citations
14 Claims
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1. A method, comprising:
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maintaining, at a processor of a computing device configured to operate as an authenticator in a communication network, a persistent authenticator epoch value that the authenticator increments each time the computing device reboots; maintaining, at the authenticator, a persistent per-supplicant value for each supplicant of the authenticator, each per-supplicant value set to a current value of the authenticator epoch value each time the corresponding supplicant establishes a new security association with the authenticator, wherein maintaining the persistent per-supplicant value for each supplicant comprises storing each persistent per-supplicant value with a corresponding pairwise temporal key (PTK) stored during each new security association; and transmitting at least one message from the authenticator to a particular supplicant, each message comprising a per-supplicant replay counter having a security association epoch counter and a message counter specific to the particular supplicant, wherein the security association epoch counter for each message is set as a difference between the authenticator epoch value and the per-supplicant value for the particular supplicant when the message is communicated, wherein the authenticator resets the security association epoch counter each time the corresponding supplicant establishes a new security association with the authenticator and the authenticator increments the security association epoch counter each time the authenticator reboots, and wherein the message counter is incremented for each message communicated; wherein the authenticator increments the security association epoch counter for the particular supplicant in response to the message counter rolling over; and
wherein the authenticator must establish a new security association with the particular supplicant if the security association epoch counter rolls over. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus, comprising:
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one or more network interfaces to communicate with a shared-media communication network; a processor coupled to the network interfaces and adapted to execute one or more processes; and a memory configured to store a process executable by the processor, the process, when executed by the apparatus as an authenticator, operable to; maintain a persistent authenticator epoch value that increments each time the apparatus reboots; maintain a persistent per-supplicant value for each supplicant of the authenticator, each per-supplicant value set to a current value of the authenticator epoch value each time the corresponding supplicant establishes a new security association with the authenticator, wherein maintaining the persistent per-supplicant value for each supplicant comprises storing each persistent per-supplicant value with a corresponding pairwise temporal key (PTK) stored during each new security association; and transmit at least one message to a particular supplicant, each message using comprising a per-supplicant replay counter having a security association epoch counter and a message counter specific to the particular supplicant, wherein the security association epoch counter for each message is set as a difference between the authenticator epoch value and the per-supplicant value for the particular supplicant when the message is communicated, wherein the authenticator resets the security association epoch counter each time the corresponding supplicant establishes a new security association with the authenticator and the authenticator increments the security association epoch counter each time the authenticator reboots, and wherein the message counter is incremented for each message communicated; wherein the authenticator increments the security association epoch counter for the particular supplicant in response to the message counter rolling over; and
wherein the authenticator must establish a new security association with the particular supplicant if the security association epoch counter rolls over. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A tangible, non-transitory, computer-readable media having software encoded thereon, the software, when executed by a processor of a computing device acting as an authenticator in a computer network, operable to:
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maintain a persistent authenticator epoch value that increments each time the computing device reboots; maintain a persistent per-supplicant value for each supplicant of the authenticator, each per-supplicant value set to a current value of the authenticator epoch value each time the corresponding supplicant establishes a new security association with the authenticator, wherein maintaining the persistent per-supplicant value for each supplicant comprises storing each persistent per-supplicant value with a corresponding pairwise temporal key (PTK) stored during each new security association; and transmit at least one message to a particular supplicant, each message using comprising a per-supplicant replay counter having a security association epoch counter and a message counter specific to the particular supplicant, wherein the security association epoch counter for each message is set as a difference between the authenticator epoch value and the per-supplicant value for the particular supplicant when the message is communicated, wherein the authenticator resets the security association epoch counter each time the corresponding supplicant establishes a new security association with the authenticator and the authenticator increments the security association epoch counter in response to the authenticator rebooting, and wherein the message counter is incremented for each message communicated; wherein the authenticator increments the security association epoch counter for the particular supplicant in response to the message counter rolling over; and
wherein the authenticator must establish a new security association with the particular supplicant if the security association epoch counter rolls over.
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Specification