Patent ID: 7003114

Claim:
A method for achieving crypto-synchronization in a packet data communication system, the packet data communication system comprising a transmitter and a receiver, said transmitter and said receiver each having cryptographic security capabilities, comprising: generating data frames at a predetermined rate in a transmitter; incrementing a state vector at said predetermined rate; providing said state vector to an encryption module; generating a codebook from said encryption module, using at least said state vector, said codebook for encrypting at least one of said data frames; detecting a delay in transmitting said data frames; dropping one or more of said frames; and disabling said state vector from incrementing for each of said data frames being dropped, wherein said dropping one or more of said data frames comprises: determining a communication channel latency; and dropping said data frames at a variable rate in accordance with said communication channel latency; and wherein said dropping said data frames at a variable rate comprises: decreasing said rate if said communication channel latency falls below at least one predetermined threshold; and increasing said rate if said communication channel latency exceeds at least one other predetermined threshold.