Apparatus, system and method for detecting a loss of key stream synchronization in a communication system

A method of validating the integrity of a data packet transmitted from a transmitter to a receiver for stream cipher out-of-synchronization detection, the method comprising:

• receiving a data packet to be transmitted from a network layer of a protocol stack of the transmitter, the data packet including a payload and a network layer checksum;
• generating a checksum based on the payload of the received data packet;
• comparing the generated checksum with the network layer checksum included in the data packet;
• encrypting the data packet by a security layer of the protocol stack of the transmitter if the checksums match, the security layer being a lower layer compared to the network layer in the protocol stack of the transmitter;
• transmitting the encrypted data packet by the transmitter to the receiver;
• decrypting, by a security layer of a protocol stack of the receiver, the encrypted data packet containing the network layer checksum and the payload, the network layer checksum included in a header of the data packet and based upon the payload, the decrypting accomplished using a forward cipher key;
• extracting the network layer checksum from the decrypted data packet;
• calculating a calculated checksum for the data packet based on the payload of the data packet;
• comparing the network layer 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 network layer checksum extracted from the decrypted data packet.