针对单一数据类型隐写方法安全性不高、隐写容量不足等问题，提出了一种具有分
级安全的多数据融合的文本隐写方法。该方法将整个载体文本中的多种类型的数据作为
备选隐写载体，以不同类型数据的隐写特点和隐写分析技术为评估依据定义隐写安全等
级，构建了一个多类数据融合的分级安全隐写模型。在具体嵌入时，根据秘密信息的长
度自适应确定安全等级，并利用分级安全隐写模型将秘密信息分散地嵌入在同一个载体
文本中相互独立的多个不同类数据中。理论分析及实验结果表明，与现有基于单一数据
类型隐写方法相比，该方法扩大了隐写容量，在嵌入等量的秘密信息情况下，降低了文
档中同一类载体数据的统计特征改变程度，提高了秘密信息的整体安全性
关键词：文本信息隐藏；隐写术；多载体；同义词替换；游程编码；分级安全；II
Abstract
With the rapid development of network and digital technology, the security of
information has also faced with severe challenge. As the current research hotspots in the field
of information security, information hiding technology provides good support for securely,
imperceptibly and completely transmitting the information. Text steganography is one kind of
text information hiding technology, which takes the text as the cover carrier for covert
communication.This thesis has made a relevant research on the text steganography and its
main contributions are presented as follows:
1. The current major research results are mainly to design the steganographic algorithm
for a single text leading to large amount of changes in statistical characteristics of the cover
text. Thus, this thesis proposed a steganography based on multiple texts and run- coding. The
proposed method takes the synonyms appearing in the multiple texts as the cover carrier, and
then encodes the synonymous words in frequency order and introduces the term of run. The
values of the elements in a run will be flipped and the run length can be changed by synonym
substitutions to implement the embedding of secret information. The positions of
substitutions dramatically and evenly distribute in the runs from different texts while
preserving the balance of forward and backward flipping the values of elements in runs.
Experimental results and analysis show that this method has improved the security of the
information transmission and enhances the ability of resisting detection attack.
2.This paper brought forward a new text steganography method with hierarchical
security resulting from the low security and capacity shortages of steganographic methods
based on the single data. First, multiple types of data in the whole cover document were
regarded as optional steganographic covers to build up a hierarchical security steganographic
model upon the the steganographic security levels defined by taking the characteristics of
different types of data and the steganalysis as evaluation criterions. Then, a security level was
adaptively determined by the secret message length, and the secret message was embedded
into the selected independent different types of data in a cover document with the help of the
built model. Theoretical analysis and experimental results show that compared with theIII
steganography based on single data, the proposed method has expanded the steganographic
capacity and reduced the modifications of the statistic characteristics of a single type of data
in the cover document when the same secret message was embedded. In conclusion the
proposed method improves the security of the secret message.
Key words: Text information hiding; Steganography; Multi-carrier; Synonym
substitution; Run coding; Hierarchical security;目 录
摘要..........I
Abstract..... II
插图索引.IV
附表索引..V
第一章 绪论.......1
1.1 研究目的及意义........ 1
1.2 国内外研究动态........ 2
1.2.1 文本隐写术研究现状.. 3
1.2.2 存在的主要问题.......... 6
1.3 本文的研究内容........ 6
1.4 论文结构........ 7
第二章 相关技术简介...8
2.1 隐写术的概念及模型 8
2.1.1 概念及基本原理.......... 8
2.1.2 隐写术的通用模型...... 8
2.1.3 隐写术的特征.. 9
2.1.4 隐写系统的安全性...... 9
2.2 典型文本隐写算法简介......... 10
2.2.1 基于同义词替换的方法........ 10
2.2.2 基于修改标识替换的方法.... 11
2.3 多载体隐写技术...... 13
2.3.1 单载体隐写模型........ 13
2.3.2 多载体隐写模型........ 14
2.4 小结.. 15
第三章 基于游程编码的多文本隐写方法.....16
3.1 引言.. 16
3.2 基于游程编码的多文本隐写方法.. 17
3.2.1 总框架 17
3.2.2 同义词编码.... 18
3.2.3 同义词游程编码........ 18
3.2.4 游程编码隐写 19
3.3 具体算法的设计...... 19
3.3.1 秘密信息的嵌入........ 19
3.3.2 秘密信息的提取........ 23
3.4 实验结果及分析...... 24
3.4.1 隐写容量分析 24
3.4.2 词频分布分析 24
3.4.3 特征值分析.... 26
3.5 小结.. 27
第四章 分级安全的多数据类型融合文本隐写方法.29
4.1 引言.. 29
4.2 多数据类型融合的隐写模型.......... 30
4.2.1 秘密信息的嵌入........ 31
4.2.2 秘密信息的提取........ 32
4.2.3 算法的实现.... 32
4.3 实验结果与分析...... 34
4.3.1 信息隐写容量 34
4.3.2 安全性分析.... 35
4.4 小结.. 40
结论.........41
1 本文研究与创新......... 41
2 进一步的研究工作..... 41
参考文献.43
致谢.........48
附录 A(攻读硕士学位期间发表和录用的学术论文)..50
附录 B(攻读硕士学位期间所参与的研究项目)..........51IV
插图索引
图 2.1 隐写术的通用模型.........8
图 2.2 同义词替换实例...........11
图 2.3 document.xml 截图示例...........12
图 2.4 基于修改标识替换信息隐藏流程图...12
图 2.5 多载体隐写理论模型...15
图 3.1 基于游程编码的多文本隐写框架.......17
图 3.2 每一组两个载体文本中隐写前后的相对词频分布图...........25
图 3.3 每一组载体文本首末文本隐写前后的相对词频分布图.......25
图 3.4 各载体文本特征值对比...........27
图 4.1 分级安全的多数据类型融合隐写模型...........30
图 4.2 不同方法的文本统计特征值...36
图 4.3 不同等级下文本统计特征值...37
图 4.4 载体文本嵌入信息前后视觉对比图...39
图 4.5 不同方法生成的隐写文档的 MCR 值39
图 4.6 不同等级的隐写文档的 MCR 值........40V
附表索引
表 3.1 原始文本载体...22
表 3.2 隐写文本载体...23
表 4.1 各种不同编码信息隐藏方法隐藏容量占总容量百分比.......35
表 4.2 文本特征值的平均值...37
表 4.3 隐写分析系统检测结果...........371
第一章 绪论
信息技术的迅猛发展一方面给人们带来了便利，另一方面也带来了一系列信息安全
问题。信息形式的多样化使得信息传输的准确性、安全性都面临着严重的威胁。为了对
信息的传输提供更可靠的保障，信息隐藏技术
。。。。。。以上简介无排版格式，详细内容请下载查看
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