Owing to its proximity to the mainland , coupled with tariffs - free arrangement under cepa , hong kong manufactures have gained a head - start in entering the mainland market . moreover , the mainland is developing its own standards such as avs , wapi , td - scdma , and hdtv standards 此外，内地正订立多项国家标准，例如数字音视频编解码技术标准( avs ) 、无线局域网加密标准( wapi ) 、时分同步码分多址接入标准( td - scdma )及高清晰度电视标准( hdtv )等。
In the design and analysis of block cipher , considering the noncontinuity of encryption and decryption of advanced encryption standard - rijndael algorithm and the arbitrariness of the choice of polynomialm ( x ) , we change the modular polynomial and the polynomials used in process of encryption and decryption , which the encryption polynomial and the decryption polynomial are the same polynomials in our choices . the new algorithm have more continuity 在分组密码的设计与分析方面：针对美国即将推出的高级加密标准rijndael算法的加解密的不一致性和rijndael算法中模多项式的选取随意性，我们修改了rijndael算法中的模多项式和加解密所用的多项式，使得加解密取相同的多项式，这样加密与解密具有更多相容性。
This article will introduces the representative of the public key system and the private key system - rsa and aes algorithm . the rsa algorithm is a widely used algorithm while the aes algorithm being the substitute of the des , is regard as the encryption standard of the 21st century . it has great actual significance to make research on such two algorithms 本论文将介绍公、私钥算法的代表? rsa和aes算法，其中rsa算法是当今应用最广泛的公钥算法，而aes算法是des的替代，被称为二十一世纪的加密标准，选择这两种算法进行研究具有很强的现实意义。
Based on the deeply investigation to the mathematical theory and principle and specification of aes , an effective implementation of aes block cipher is completed and the encryption and decryption are also completed by using c language . in this paper , the rsa public - key cryptosystem and digital signature are also discussed deeply 本课题对美国国家标准技术研究所( nist )推出的用于下一世纪数据加密标准的高级数据加密标准( aes )进行了跟踪研究，深入研究了aes的数学原理、加密解密的算法实现过程，并用c语言完整地实现了aes算法。
Aes will take the place of des and become new standard of encryption . we programmed the source code for the algorithm in vc and gave the result . hash function is another methods that ensure integrality of data and guarantee that message content is not altered during the transmission between the riginator and the recipient 本论文在这一草案的基础上深入分析它的加密、解密和密钥产生过程，论证了其较之数据加密标准des的众多优点，并用程序实现了aes - 128的加密过程，给出了实验结果。
