Preventing shortened lifetimes of security keys in a wireless communications security system

• US RE47,200 E1
• Filed: 05/21/2014
• Issued: 01/08/2019
• Est. Priority Date: 08/16/2001
• Status: Expired due to Term

• Current Assignee: L2 Mobile Technologies LLC (Tanit Ventures Inc.)
• Original Assignee: L2 Mobile Technologies LLC (Tanit Ventures Inc.)
• Inventors: Jiang, Sam Shiaw-Shiang, Kuo, Richard Lee-Chee, Ho, Chi-Fong
• Primary Examiner(s): SAGER, MARK ALAN
• Application Number:
  US14/283,801
• Time in Patent Office: 1,693 Days
• Field of Search: 380278, 380270, 380261, 380247, 4554351
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/18 using different networks or channels, e.g. using out of band channels cryptographic mechanisms or cryptographic arrangements for key distribution involving distinctive intermediate devices or communication paths H04L9/0827; cryptographic mechanisms or cryptographic arrangements for authentication using a plurality of channels H04L9/3215
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]

Abstract

23A wireless communications device has a first security key, a second security key, and established channels. Each established channel has a corresponding security count value, and utilizes a security key. At least one of the established channels utilizes the first security key. The second security key is assigned to a new channel. A first set is then used to obtain a first value. The first set has only security count values of all the established channels that utilize the second key. The first value is at least as great as the x most significant bits (MSB_x) of the greatest value in the first set. The MSB_x of the initial security count value for the new channel is set equal to the first value. If the first set is empty, then the initial security count is set to zero.

Claims

1. A method for calculating an initial security count value for a new channel in a wireless communications device, the wireless communications device comprising:

a first security key;

a second security key; and

a plurality of established channels, each established channel having a corresponding security count value and utilizing a security key, at least one of the established channels utilizing the first security key;

the method comprising;

assigning the second security key to the new channel;

utilizing a first set to obtain a first value, the first set consisting of corresponding security count values of the established channels that utilize the second key, the first value being at least as great as the x most significant bits (MSB_x) of a value in the first set; and

setting the MSB_x of the initial security count value for the new channel equal to the first value;

wherein if the first set is empty, then the first value is set to a first predetermined value.

2. The method of claim 1 wherein the first predetermined value is zero.

3. The method of claim 2 wherein the first value is at least as great as the MSB_x of the greatest value in the first set.

4. The method of claim 3 wherein the first value is greater than the MSB_x of the greatest value in the first set.

5. A method for providing an initial security count value to a new channel in a wireless communications device, the method comprising:

establishing at least a first channel, each first channel utilizing a first security key and having a corresponding security count value;

performing a security mode reconfiguartion to change utilization of each first channel from the first security key to a second security key according to an activation time for each first channel;

wherein upon utilization of the second security key, the corresponding security count value for the first channel is changed;

initiating establishment of a second channel that utilizes the second security key;

utilizing a first set to obtain a first value, the first set consisting of corresponding security count values of the established channels that utilize the second key, the first value being at least as great as the x most significant bits (MSB_x) of a value in the first set; and

setting the MSB_x of the initial security count value for the second channel equal to the first value;

wherein if the first set is empty, then the first value is set to a first predetermined value.

6. The method of claim 5 wherein the first set includes the corresponding security count values of all first channels utilizing the second security key when initiating the establishment of the second channel.

7. The method of claim 6 wherein the predefined value is zero.

8. The method of claim 5 wherein the first value is at least as great as the MSB_x of the greatest value in the first set.

9. The method of claim 8 wherein the first value is greater than the MSB_x of the greatest value in the first set.

10. A method for calculating an initial security count value for a new channel, the method comprising:

establishing a plurality of established channels in a wireless communication device, wherein each established channel in the wireless communication device has a corresponding security count value and utilizes a first security key;

performing a security mode reconfiguration to change utilization of each of the established channels in the wireless communication device from the first security key to a second security key according to an activation time for each of the established channels, wherein upon utilization of the second security key by one of the established channels, the corresponding security count value for the one of the established channels is changed, wherein the second security key is a new security key that replaces the first security key and is different from the first security key;

initiating establishment of a new channel in the wireless communication device;

assigning the second security key to the new channel;

utilizing a first set to obtain a first value, wherein the first set is consisting of corresponding security count values of the established channels in the wireless communication device that utilize the second key, and wherein the first value is at least as great as the x most significant bits (MSBx) of a value in the first set and at least one of the established channels utilizing the first security key; and

setting the MSBx of the initial security count value for the new channel equal to the first value, wherein if the first set is empty, then the first value is set to a first predetermined value.

11. The method of claim 10, wherein the first predetermined value is zero.

12. The method of claim 10, wherein the first value is a least as great as the MSBx of the greatest value in the first set.

13. The method of claim 10, wherein the first value is greater than the MSBx of the greatest value in the first set.

14. The method of claim 10, wherein the first set includes the corresponding security count values of each established channel in the wireless communication device utilizing the second security key when initiating the establishment of the new channel in the wireless communication device.