Patent ID: 6542607
Filing Date: 2003-04-01
Classification: H04L

Abstract:
A system for cryptographic processing of a digital data stream having an arbitrary number of data blocks, for recognition of a modification of a sequence of the cryptographically processed data blocks, comprising a processing unit for at least a part of the data blocks, the processing unit comprising:a first logic unit to which a respective data block is supplied via a first input, to which at least one preceding data block is supplied via a second input, and to which at least one preceding intermediate quantity is supplied via a third input, the first logic unit constructed such that a combination quantity is determined by combining the respective data block, the preceding data block and the preceding intermediate quantity; an encryption unit, with which an intermediate quantity is determined by applying a block encryption method to the combination quantity; and a second logic unit, to which the intermediate quantity is supplied via a first input and to which at least one preceding cryptographically processed data block is supplied via a second input, the second logic unit constructed such that a respective cryptographically processed data block is determined by combining the intermediate quantity and the preceding cryptographically processed data block.