| For several years the "information highway" has been growing rapidly and changing our lives. Within any minute, a huge amount of information is exchanged through the Internet. Many kinds of information exchanges, for example audio/video content exchanges in multimedia communication, should be protected from unauthorized copying, intercepting and tampering as they are traversing on public digital networks. Accordingly, cryptography has become more important in data security. Public-key and symmetric-key cryptography algorithms possess different properties for data communications. In practice, hybrid cryptosystems, where the symmetric-key cryptography is for fast data encryption and decryption, and the rest is handled by the public-key cryptography, are used for high speed multimedia communications.; Proposed unified programmable cellular automata can be used for hybrid systems. In this system, a public-key cryptosystem and a symmetric-key cryptosystem can be implemented using unified PCA with the same structure. Point-of-deployment (POD) security module, which is another hybrid cryptosystem proposed by OpenCable(TM), allows viewers to receive cable systems' secure digital video services. These services include impulse pay-per-view, video-on-demand as well as other interactive services such as e-commerce communication.; This thesis presents a unified PCA for hybrid cryptosystems and the implementation of POD based on the digital signal processors (DSP), which enable high speed communication for the real-time application. We design the whole construction of POD with DSP TMS320C6211, and implement the major algorithms of POD, which include elliptic curve digital signature algorithm (ECDSA), elliptic curve Diffie Hellman (ECDH) key exchange, elliptic curve key derivation function (ECKDF), cellular automata (CA) cryptography, RC6 block cipher algorithm, communication processes between POD and Host, and Host authentication. The testing performance satisfies the real-time video data transmission requirement. |
