US Patent 8180917 Packet threshold-mix batching dispatcher to counter traffic analysis

An antivirus agent located on a user computer, local area network or standalone hardware device includes a statistical module, a control unit, a timeslot generator and a dispatcher. The statistical module calculates statistics for incoming request packets including the burstiness degree H. A number of normal distributions are predefined. A number of probability sequences are predefined. An input statistic is used to select one of the probability sequences. This probability sequence is used to select a timer value from the distributions. Packets are loaded into a variable-length buffer in the dispatcher to form the timer expires or when the buffer is full. The rate of the output traffic from the dispatcher depends upon a selected distribution value by the timeslot generator and not by any manufactured timing by an attacker. Output traffic frequency is shaped by the dispatcher; packets may go out faster or slower, thus thwarting an attacker who relies upon their own inserted packet timing.