Patent ID: 6876746
Filing Date: 2005-04-05
Classification: H04K,H04N

Abstract:
1. A digital processing device for performing an encryption/decryption operation, comprising: a circular arrangement of two or more processing stages, wherein each processing stage receives as input one different processing stage's output, wherein any given processing stage performs a function on digital data received at the given processing stage's input to produce the given processing stage's output; first stage circuitry for receiving a first digital data word, performing an operation on the first digital data word and outputting a first processed data word; second stage circuitry coupled to the first stage circuitry for receiving the first processed data word and outputting a second processed data word; processing control circuitry for controlling the processing stages so that a digital data word is received and processed by the first stage and, thereafter, by each successive stage in the circular arrangement so that when the processed digital data word is output by a last stage, the processed digital data word is transferred back to the first stage at least once before being finally output by the last stage; a buffer coupled between the first and second stage circuitry for storing the first processed data word to suspend processing of the first digital data word; and control circuitry for causing the circular arrangement of two or more processing stages to begin processing a second digital data word and for later causing suspension of processing of the second digital data word and resuming processing of the first digital data word.