Apparatus, system and method for detecting a loss of key stream system synchronization in a communication system
View Patent ↗An apparatus, system and method provides an out-of-synchronization detection by using a network layer checksum. A process operating at an upper layer verifies that a checksum embedded in a network layer header is correct before encrypting and transmitting a data packet containing the header and a payload. The data packet is received through a wireless communication channel at a receiver and decrypted. A calculated checksum is calculated on the received payload at the receiver and compared to the received checksum embedded in the header. A key stream used at the receiver for decrypting the received encrypted data packets is determined to be out of synchronization with a key stream used at the transmitter to encrypt the data packets if the calculated checksum is not equal to the network layer checksum.
1. A receiver comprising:
a processor; and
computer-readable storage in communication with the processor, the computer-readable storage storing logical instructions that are executed by the processor to perform operations including:
receiving a data packet from a code stream at a sub-network security layer, the data packet containing a checksum and a payload, the checksum included in a header of the data packet,
decrypting the data packet, using a forward cipher key,
extracting the checksum from the header of the data packet,
calculating a calculated checksum for the data packet,
comparing the calculated checksum with the extracted checksum to determine an integrity of the data packet,
resetting the code stream upon a determination that the integrity of the data packet is compromised, and
transmitting the data packet to a network layer upon a determination that the integrity of the data packet is not compromised.
2. The receiver of claim 1 , wherein the processor further performs operations including detecting a loss of stream cipher synchronization if the calculated checksum does not match the extracted checksum.
3. The receiver of claim 1 , wherein the processor further performs operations including receiving the data packet at a data link layer, the data link layer providing communications through a wireless communication channel to transfer the data packet to the sub-network security layer.
4. The receiver of claim 3 , wherein the processor further resets the data link layer if the calculated checksum does not match the extracted checksum.
5. The receiver of claim 1 , wherein the processor further re-synchronizes a stream cipher with a transmitter of the data packet if the calculated checksum does not match the extracted checksum.
6. A communication system comprising:
a controller including at least a processor;
wherein the processor executes logical instructions including:
receiving an encrypted data packet of a code stream at a controller, the encrypted data packet containing a checksum and a payload, the checksum included in a header of the data packet and based upon the payload,
transmitting the encrypted data packet to a sub-network security layer,
decrypting the encrypted data packet using a forward cipher key to extract the checksum;
calculating a calculated checksum for the decrypted data packet;
comparing the calculated checksum with the extracted checksum to determine an integrity of the data packet;
resetting the code stream upon a determination that the integrity of the data packet is compromised, and
transmitting the data packet to a network layer upon a determination that the integrity of the data packet is not compromised.
7. The system of claim 6 , wherein the instructions further include detecting a loss of stream cipher synchronization if the calculated checksum does not match the extracted checksum.
8. The system of claim 6 , wherein the payload is encrypted at a transmitter network layer to form the encrypted data packet.
9. The system of claim 8 , wherein the encrypted data packet is received through a wireless channel at a data link layer.
10. The system of claim 9 , wherein the data link layer provides communications through the wireless channel to transfer the encrypted data packet to the sub-network security layer.
11. The system of claim 10 , wherein the instructions further include resetting the data link layer if the calculated checksum does not equal the extracted checksum.
12. The system of claim 6 , wherein the instructions further include re-synchronizing a stream cipher with a transmitter of the encrypted data packet if the calculated checksum does not match the extracted checksum.
13. A non-transitory computer-readable medium storing a computer-readable logic that is executed by a processor to perform operations including:
decrypting a data packet containing a checksum and a payload, the data packet being part of a code stream received at a controller and transmitted to a sub-network security layer, the checksum included in a header of the data packet and based upon the payload, the decrypting accomplished using a forward cipher key;
extracting the checksum from the decrypted data packet;
calculating a calculated checksum for the data packet, the calculated checksum generated by a checksum generator based on the payload of the data packet;
comparing the checksum extracted from the decrypted data packet with the calculated checksum at a checksum validation engine; and
detecting a loss of stream cipher synchronization if the calculated checksum does not match the checksum extracted from the decrypted data packet;
wherein the controller resets the code stream upon a determination of the loss of stream cipher synchronization; and
wherein the controller transmits the data packet to a network layer upon a determination that the integrity of the data packet is not compromised.
14. The non-transitory computer-readable medium of claim 13 , wherein detecting the loss of stream cipher synchronization is performed at a network layer of a protocol stack.
15. The non-transitory computer-readable medium of claim 14 , wherein the operations further include re-synchronizing a stream cipher with a transmitter of the encrypted data packet if the calculated checksum does not match the checksum extracted from the decrypted data packet.
16. The non-transitory computer-readable medium of claim 13 , wherein the operations further include comparing the calculated checksum and the checksum extracted from the decrypted data packet both for a network layer data payload.
17. The non-transitory computer-readable medium of claim 13 , wherein the operations further include resetting a data link layer if the calculated checksum does not equal the checksum extracted from the decrypted data packet.