Patent ID: 7076060

Claim:
Encipher apparatus for enciphering a signal, comprising: forming means for receiving the signal to be enciphered and for outputting the signal as a sequence of data blocks, each having a first predetermined number of bits; a plurality of encipher functional modules sequentially coupled to operate sequentially on the sequence of data blocks from the forming means; and configuring means, wherein each encipher functional module comprises a module input, a module output, and a respective data processing unit having a parallel input and a corresponding parallel output and being arranged to perform a respective reversible process upon a set of bits at its parallel input and to produce at its corresponding parallel output a corresponding enciphered set of bits; and each encipher functional module is operable under the control of the configuring means to couple a respective predetermined set of the bits of a data block received at its module input to the parallel input of its data processing unit and to provide at its module output an enciphered data block in which said respective predetermined set of bits is replaced by the corresponding enciphered set of bits produced at the parallel output of its data processing unit.