Patent ID: 8213603
Filing Date: 2012-07-03
Classification: H04L

Abstract:
1. An encryption processing apparatus comprising: a first register device configured to include a first data register and a first flag register; a second register device configured to include a second data register and a second flag register; a first flag operation device configured to perform flag operations on first data and second data of an input plain text for each group of a predetermined number of bits; a first operation device configured to cause said first flag operation device to perform exclusive-OR operations on each of said first and said second data and on the flags in effect for flag control, said first operation device being further configured to feed the flag-controlled first data and first flag to said first register device and the flag-controlled second data and second flag to said second register device; a second operation device configured to perform exclusive-OR operations on the latched data in said second data register of said second register device and on the flag of the second flag register; a round operation device configured to perform a round operation on output data from said second operation device; a third and a fourth operation device configured to perform exclusive-OR operations on the output from said round operation device and on the latched value in said first data register of said first register device as well as on the flag of said first flag register; a second flag operation device configured to perform a new flag operation on output data from said third and said fourth operation devices for each group of a predetermined number of bits; and a fifth operation device configured to cause said second flag operation device to perform exclusive-OR operations on the output data from said third and said fourth operation devices and on the flags in effect for flag control, said fifth operation device being further configured to output the flag-controlled data and flags to said second register device.