Abstract: The encryption/decryption device includes a plaintext unit, a ciphertext unit and a cryptographic unit connected therebetween. The plaintext unit may include a logic device such as a first programmable logic device (PLD), e.g. a field programmable gate array (FPGA), for interfacing with the protected network to perform encapsulation of data from the protected network to define outgoing datagrams, and to perform decapsulation of incoming datagrams from the cytographic unit. The ciphertext unit may include a second logic device such as a PLD or FPGA for interfacing with the unprotected network to perform routing of incoming encrypted datagrams from the unprotected network to the cryptographic unit, and to perform routing of outgoing encrypted datagrams from the cryptographic unit to the unprotected network.

Abstract: A cryptographic device includes an input stage receiving an input data block and a key data block made up of a plurality of sub-key data blocks, and generating a plurality of first signals therefrom. An intermediate stage is connected to the input stage and includes a plurality of substitution units. Each substitution unit substitutes data within a respective first signal. A diffuser is connected to the plurality of substitution units for mixing data to generate a diffused signal. An output stage is connected to the intermediate stage for repetitively looping back the diffused signal to the input stage for combination with a next sub-key data block. The output stage provides an output signal for the cryptographic device after the repetitively looping back is complete.

Abstract: The encryption/decryption device includes a plaintext unit, a ciphertext unit and a cryptographic unit connected therebetween. The plaintext unit may include a logic device such as a first programmable logic device (PLD), e.g. a field programmable gate array (FPGA), for interfacing with the protected network to perform encapsulation of data from the protected network to define outgoing datagrams, and to perform decapsulation of incoming datagrams from the cytographic unit. The ciphertext unit may include a second logic device such as a PLD or FPGA for interfacing with the unprotected network to perform routing of incoming encrypted datagrams from the unprotected network to the cryptographic unit, and to perform routing of outgoing encrypted datagrams from the cryptographic unit to the unprotected network.