Apparatus for encryption of Data Encryption Standard of Cipher Block Chaining mode

摘要

PURPOSE: A data encryption standard(DES) encryption device of an encryption block chain method is provided to reduce the timing by moving the position of input buffer register into the exclusive logic sum operation block required to the DES operation, thereby improving the performance of the DES encryption device. CONSTITUTION: A data encryption standard(DES) encryption device of an encryption block chain method includes a pair of exclusive logic sum operation blocks(51,52). In the DES encryption device, the input buffer registers(IBR(L),IBR(R)) include an exclusive logic sum operation block(51) receiving the output of the left register(A0) and the input of the left input bus, a left input buffer register(IBR(L)) for receiving the output of the exclusive logic sum operation block(51), the exclusive logic sum operation block(52) for receiving the output of the right register(B0) and the input of the right input bus and the right input buffer register(IBR(R)) receiving the output of the exclusive logic sum operation block(52).