Hybrid Crypto Hardware Utilizing Symmetric-Key and Public-Key Cryptosystems

This paper proposes a hybrid crypto system that utilizes benefits of both symmetric key and public key cryptographic methods. Symmetric key algorithms (DES and AES) are used in the crypto system to perform data encryption. Public key algorithm (RSA) is used in the crypto system to provide key encryption before key exchange. Combining both the symmetric-key and public-key algorithms provides greater security and some unique features which are only possible in this hybrid system. The crypto system design is modeled using Verilog HDL. The implementation has various modules for DES, AES and RSA. The implementation also has a pseudorandom number generation unit for random generation of keys and a GCD computation unit for RSA. All the hardware modules are designed by Register Transfer Level (RTL) modeling of Verilog HDL using Model Sim SE 5.7e. showing interesting promising results.