Dissertation > Industrial Technology > Radio electronics, telecommunications technology > Communicate > Confidentiality of communications and communications security > Theory

DR Stinson \

Author LiuBaoHui
Tutor ZhangBingRu
School Qinghai Normal
Course Basic mathematics
Keywords Shift password Affine Cipher Virginia password Cryptanalysis Frequency Probability Huffman coding Entropy
CLC TN918.1
Type Master's thesis
Year 2010
Downloads 17
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In this paper, the D.R. sting's "cryptography" in some traditional coding and decoding method for minor study. And some improvement is presented. Paper innovation points are: 1. The shift password a decoding method is given. 2. The traditional decoding method of affine cipher, under some conditions can decipher succeed, indecipherable success and in some conditions. We - the new decoding method is given, can be successful in any conditions can decipher. 3. Improve the Virginia password about the probability of an error in the formula, also the last step of cryptanalysis, Virginia was improved, and the decoding speed. 4. The expression of Huffman coding is improved to reduce the weighted average of the length of coding. Negative hoffman sequence coding is given, from coding, considering the size of the weighted average of the length of this method has a better than Huffman coding. 5. Some new properties of entropy is presented.

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