Some Applications Of Parallel Computing In Information Security

With the rapid development of network informationization, the Internet brings an unprecedented mass of information meanwhile the nework information security issues are more and more serious. As a way to solve computer security problems, Cryptography and watermarking technology have been concerned in recent years.On the basis of the LUC and the ElGamal public key cryptography, associated with the current multi-core technology development, their parallel algorithms and a digital watermarking scheme based on the batch processing are proposed. Rearch includes the following areas:First of all, ElGamal public key cryptosystem is researched. Its encryption need to calculate a pair of ciphertexts which are independent with each other and have the property of parallel, so the ciphertext can be parallel computing. This program has effectively accelerated the encryption speed of the ElGamal public key cryptosystem.Secondly, the property of LUC public key cryptosystem’s encryption and decryption has a direct relationship with large number of modular arithmetic, therefore the modular arithmetic of large integer is decomposed into two smaller primes’ modular arithmetic with Chinese Remainder Theorem to design and implement parallel algorithm of LUC public key cryptosystem.Thirdly, for the field structure m=m1m2...mn of the LUC public key cryptosystem, large number is decomposed into several smaller primes to encrypt and decrypt by using the Chinese Remainder Theorem and Fundamental Theorem of Arithmetic. This method is advantageous for the execution of parallel computing.Finally, the combination of the LUC public key cryptosystem, digital watermarking scheme based on batch processing is proposed. The program can solve the problem of a number of works to embed watermark in reality which needs a lot of time.The parallel algorithms of ElGamal and LUC public key cryptosystem designed in the thesis are realized by calling Miracle big integer library and the platform of VS2010and MPI. Digital watermarking scheme based on batch processing is relized on Matlab2011b.Speedup and CPU efficiency are important indicators which can measure the performance of parallel algorithm. The speedup and CPU efficiency of the proposed algorithm are computed. The experimental results show that the proposed parallel algorithms are effective and feasible.