CN104504342B - Method using invisible character hiding information is encoded based on Unicode - Google Patents

Method using invisible character hiding information is encoded based on Unicode Download PDF

Info

Publication number
CN104504342B
CN104504342B CN201410733815.0A CN201410733815A CN104504342B CN 104504342 B CN104504342 B CN 104504342B CN 201410733815 A CN201410733815 A CN 201410733815A CN 104504342 B CN104504342 B CN 104504342B
Authority
CN
China
Prior art keywords
secret
carrier
key
unicode
executing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201410733815.0A
Other languages
Chinese (zh)
Other versions
CN104504342A (en
Inventor
吴槟
易小伟
赵险峰
冯凯
何晓磊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institute of Information Engineering of CAS
Original Assignee
Institute of Information Engineering of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institute of Information Engineering of CAS filed Critical Institute of Information Engineering of CAS
Priority to CN201410733815.0A priority Critical patent/CN104504342B/en
Publication of CN104504342A publication Critical patent/CN104504342A/en
Application granted granted Critical
Publication of CN104504342B publication Critical patent/CN104504342B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
    • G06F21/60—Protecting data
    • G06F21/62—Protecting access to data via a platform, e.g. using keys or access control rules
    • G06F21/6218—Protecting access to data via a platform, e.g. using keys or access control rules to a system of files or objects, e.g. local or distributed file system or database
    • G06F21/6245—Protecting personal data, e.g. for financial or medical purposes
    • G06F21/6263—Protecting personal data, e.g. for financial or medical purposes during internet communication, e.g. revealing personal data from cookies

Abstract

The present invention proposes a kind of method using invisible character hiding information based on Unicode codings, mainly includes message embedded mobile GIS and message extraction algorithm.Secret information is hidden by using the Unicode coding characteristics of invisible character, the embedding capacity of secret information is improved on the premise of security is ensured.Using the present invention, secret information can be hidden on the text carrier containing the invisible character such as space using Unicode codings；The insertion form of secret information can neatly be changed according to coding schedule to ensure the safety of information；The embedding capacity of secret information can be effectively improved.

Description

Method for hiding information by using invisible characters based on Unicode coding
Technical Field
The invention relates to a method for hiding information by using invisible characters based on Unicode coding, belonging to the technical field of information hiding.
Background
With the popularization of computer applications and the rapid development of the internet, people put higher demands on network communication security. Unlike information encryption techniques, information hiding techniques safeguard communication security by masking the existence of the behavior of transmitting messages. Currently, as the application of text documents is more and more widespread, hiding secret messages by using text documents becomes a research direction in the field of information security. In the field of computer science, unicode is a universal character set encoding standard and is widely applied to modern operating systems. Almost all word processors support Unicode encoding, parsing and storage of text data.
Invisible characters refer to a set of characters that are invisible when a document is printed, including spaces, tab characters, line breaks, and the like. Generally, hiding the secret message by using invisible characters has the advantages of being not easy to perceive, simple to operate, strong in concealment and the like. The WbStego4 software is an open source tool for hiding information by using invisible characters, and supports various data formats such as TXT, HTML, PDF and the like. But it does not support information hiding of chinese text data carriers and has a limited information embedding capacity, which has great limitations in practical applications.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects of the existing WbStego4 software technology, provide a method for hiding information by using invisible characters based on Unicode coding, be suitable for hiding information by using Chinese and English text carriers containing invisible characters based on Unicode coding, improve the capacity of the hidden information on the premise of ensuring the safety, and better meet the requirements of hidden communication.
The technical scheme of the invention is a method for hiding information by using invisible characters based on Unicode coding, which mainly comprises two parts of a message embedding algorithm and an extraction algorithm:
and a message embedding algorithm for re-encoding invisible characters in a carrier object according to an encoding table, and embedding the secret message into the carrier object, wherein the carrier object is Chinese and English text data based on Unicode encoding, and the invisible characters comprise half-angle/full-angle spaces and tabulation characters (corresponding Unicode codes are represented as 0x20, 0x 30 and 0x09 respectively). The input data of the embedded algorithm is the carrier object, the secret message and the coding table, and the output data is the carrier with the secret.
The message extraction algorithm is a reverse algorithm of the embedding algorithm, and recovers the secret message from the carrier with the secret according to the coding table. The input data of the extraction algorithm comprises a carrier with secret and a coding table, and the output data is a secret message.
The invention discloses a method for hiding information by using invisible characters based on Unicode coding, which hides secret information in a text carrier by using the coding characteristics of the invisible characters, and comprises the following steps:
(1) Sending the protocol secret key of the sending party and the receiving party, and respectively constructing an encoding table according to the secret key;
(2) A sender selects a carrier object, and embeds a secret message into the carrier object through information embedding according to the coding table generated in the step (1) to obtain a carrier with secret;
(3) The sender transmits the carrier with secret obtained in the step (2) to a receiver through a communication channel;
(4) And (3) the receiver extracts the secret message from the carrier with the secret received in the step (3) through an extraction algorithm according to the coding table generated in the step (1) to obtain the secret message.
Compared with the prior art, the invention has the beneficial effects that:
(1) In the present invention, the choice of carrier objects is broader. The carrier object suitable for hiding the secret message can select the text data based on the Unicode coding so as to meet the requirement of practical application.
(2) In the invention, the security of the algorithm is ensured by utilizing the key generated by the key generator. The secret key can control the generation of the coding table, and under the premise of ensuring the safety of the information hiding algorithm, the message embedding/extracting operation and the message encrypting/decrypting operation are combined, so that the complexity of the operation and the energy consumption in the practical application are reduced.
(3) In the invention, the capacity of the embedded information is improved by utilizing the coding table. When the code table is prepared, a code table consisting of 256 one-to-one mapping relations is designed by utilizing the redundant invisible character code words in the Unicode, wherein the mapping relation of the code table is controlled by a secret key. The coding table raises the information rate from 1 bit to 8 bits at a time.
Drawings
FIG. 1 is a flow chart of an implementation of a method embodiment of the present invention;
FIG. 2 is a flow chart of an implementation of a message embedding algorithm in the method of the present invention;
fig. 3 is a flow chart of an implementation of a message extraction algorithm in the method of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
As shown in FIG. 1, it is a flow chart for implementing the present inventionTo this end, the information hiding method can be represented as a six-tuple, i.e., $=<C,S,T k ,C',E k ,D k &gt, where C is a set of carrier objects, S is a set of secret messages, T k A code table constructed according to the secret key k, a secret carrier set obtained after C' hides the secret message for the carrier object, and E k Embedding an algorithm for messages, D k An algorithm is extracted for the message. In the information hiding method Σ,2 main algorithm blocks are included: and the message embedding algorithm module and the message extraction algorithm module are respectively called by the sender and the receiver. The functions of the modules are described as follows:
1. message embedding algorithm
The sender constructs an encoding table T according to the secret key k k The secret information S input by the sender is embedded into the selected carrier object C, and the carrier with the secret C' is output. The sender then transmits the secret carrier C' to the receiver over a communication channel. Performing message embedding algorithm E k Can be expressed as:
E k :C×M×T k →C′
2. message extraction algorithm
The receiving party constructs an encoding table T according to the extracted secret key k k And extracting the secret information M from the carrier C' with the secret, which is obtained from the sender, by an extraction algorithm. Performing message extraction Algorithm D k Can be expressed as:
D k :C′×T k →M
as shown in fig. 1, the specific implementation process of the present invention is as follows:
1. coding table structure
The present invention controls the encoding table T by a secret key k shared by a sender and a receiver k The generation of the hidden information improves the capacity of the hidden information on the premise of ensuring the coding safety so as to meet the requirement of practical application. The specific implementation steps for constructing the coding table are as follows:
(1) The key k must be a 2048 bit binary string that can be expressed in decimal fashion as
k＝(n 0 ,n 1 ,…,n i ,…,n 255 ),n i ∈N∩[0,255],i＝0,1,…255
Furthermore, each component n of the key k i The following conditions must also be satisfied
The above description shows that: the key k may be expressed as a permutation of a sequence of integers from 0 to 255 as shown in the following equation
k＝perms(0,1,2,…,255)
Where perms () is a permutation function.
(2) According to the characteristics of the Unicode code, the sender and the receiver find out the optional code words of 256 invisible characters in advance as the construction basis of the coding table shared by the two parties (each code word must be 2-byte Unicode code). An example of a hexadecimal representation of 256 alternative codewords is given in table 1.
(3) According to the step (1) and the step (2), establishing an encoding table T from the key to the optional code word k . Table 1 shows the coding table constructed with the key k = (0,1,2, …, 255).
TABLE 1 coding table
m Code word m Code word m Code word m Code word m Code word m Code word m Code word
00 00 D8 25 01 E4 4A 02 F8 6F 04 E3 94 05 F7 B9 07 E2 DE 08 F6
01 00 D9 26 01 E5 4B 03 D8 70 04 E4 95 05 F8 BA 07 E3 DF 08 F7
02 00 DA 27 01 E6 4C 03 D9 71 04 E5 96 06 D8 BB 07 E4 E0 08 F8
03 00 DB 28 01 E7 4D 03 DA 72 04 E6 97 06 D9 BC 07 E5 E1 09 D8
04 00 DC 29 01 F0 4E 03 DB 73 04 E7 98 06 DA BD 07 E6 E2 09 D9
05 00 DD 2A 01 F1 4F 03 DC 74 04 F0 99 06 DB BE 07 E7 E3 09 DA
06 00 DE 2B 01 F2 50 03 DD 75 04 F1 9A 06 DC BF 07 F0 E4 09 DB
07 00 DF 2C 01 F3 51 03 DE 76 04 F2 9B 06 DD C0 07 F1 E5 09 DC
08 00 E0 2D 01 F4 52 03 DF 77 04 F3 9C 06 DE C1 07 F2 E6 09 DD
09 00 E1 2E 01 F5 53 03 E0 78 04 F4 9D 06 DF C2 07 F3 E7 09 DE
0A 00 E2 2F 01 F6 54 03 E1 79 04 F5 9E 06 E0 C3 07 F4 E8 09 DF
0B 00 E3 30 01 F7 55 03 E2 7A 04 F6 9F 06 E1 C4 07 F5 E9 09 E0
0C 00 E4 31 01 F8 56 03 E3 7B 04 F7 A0 06 E2 C5 07 F6 EA 09 E1
0D 00 E5 32 02 D8 57 03 E4 7C 04 F8 A1 06 E3 C6 07 F7 EB 09 E2
0E 00 E6 33 02 D9 58 03 E5 7D 05 D8 A2 06 E4 C7 07 F8 EC 09 E3
0F 00 E7 34 02 DA 59 03 E6 7E 05 D9 A3 06 E5 C8 08 D8 ED 09 E4
10 00 F0 35 02 DB 5A 03 E7 7F 05 DA A4 06 E6 C9 08 D9 EE 09 E5
11 00 F1 36 02 DC 5B 03 F0 80 05 DB A5 06 E7 CA 08 DA EF 09 E6
12 00 F2 37 02 DD 5C 03 F1 81 05 DC A6 06 F0 CB 08 DB F0 09 E7
13 00 F3 38 02 DE 5D 03 F2 82 05 DD A7 06 F1 CC 08 DC F1 09 F0
14 00 F4 39 02 DF 5E 03 F3 83 05 DE A8 06 F2 CD 08 DD F2 09 F1
15 00 F5 3A 02 E0 5F 03 F4 84 05 DF A9 06 F3 CE 08 DE F3 09 F2
16 00 F6 3B 02 E1 60 03 F5 85 05 E0 AA 06 F4 CF 08 DF F4 09 F3
17 00 F7 3C 02 E2 61 03 F6 86 05 E1 AB 06 F5 D0 08 E0 F5 09 F4
18 00 F8 3D 02 E3 62 03 F7 87 05 E2 AC 06 F6 D1 08 E1 F6 09 F5
19 01 D8 3E 02 E4 63 03 F8 88 05 E3 AD 06 F7 D2 08 E2 F7 09 F6
1A 01 D9 3F 02 E5 64 04 D8 89 05 E4 AE 06 F8 D3 08 E3 F8 09 F7
1B 01 DA 40 02 E6 65 04 D9 8A 05 E5 AF 07 D8 D4 08 E4 F9 09 F8
1C 01 DB 41 02 E7 66 04 DA 8B 05 E6 B0 07 D9 D5 08 E5 FA 0A D8
1D 01 DC 42 02 F0 67 04 DB 8C 05 E7 B1 07 DA D6 08 E6 FB 0A D9
1E 01 DD 43 02 F1 68 04 DC 8D 05 F0 B2 07 DB D7 08 E7 FC 0A DA
1F 01 DE 44 02 F2 69 04 DD 8E 05 F1 B3 07 DC D8 08 F0 FD 0A DB
20 01 DF 45 02 F3 6A 04 DE 8F 05 F2 B4 07 DD D9 08 F1 FE 0A DC
21 01 E0 46 02 F4 6B 04 DF 90 05 F3 B5 07 DE DA 08 F2 FF 0A DD
22 01 E1 47 02 F5 6C 04 E0 91 05 F4 B6 07 DF DB 08 F3
23 01 E2 48 02 F6 6D 04 E1 92 05 F5 B7 07 E0 DC 08 F4
24 01 E3 49 02 F7 6E 04 E2 93 05 F6 B8 07 E1 DD 08 F5
In the invention, the coding table is used as the input of the message embedding algorithm module and the extracting algorithm module, and the coding tables constructed by the sender and the receiver through the secret key k are the same, so the coding table T input into the embedding algorithm module k With the coding table T input to the extraction algorithm module k And (5) the consistency is achieved.
2. Message embedding
The message embedding algorithm module executing the embedding algorithm E () in the present invention can be expressed as
c′＝E(c,m,T k )
Wherein, the module input parameters comprise a carrier object c, a secret message m to be embedded and an encoding table T generated by an embedded key k k The module output is the carrier with secret c' containing the secret message. In addition, the invention requires the carrier c of the embedded information to be text data based on Unicode coding, including TXT format text and text data in Word, PDF, XML and HTML compound documents; and m is processed as a byte stream in the embedding module, so m can be TXT text data and JPEG image data.
The implementation flow chart of the embedding algorithm is shown in fig. 2, and the specific implementation steps are as follows:
(1) Preprocessing the incoming carrier object c, replacing c with 0x2000 the code table T that appears in c k The code word of (a);
(2) Sequentially reading 2 byte data xx of c and judging whether xx is 0x0000;
(3) If the result in the step (2) is no, executing the step (4), otherwise, executing the step (12 a);
(4) Judging whether xx is an invisible character or not, wherein the xx comprises a half-angle/full-angle space and a tab, and the Unicode code expressions corresponding to xx are 0x2000, 0x0030 and 0x0900 respectively;
(5) If the result in the step (4) is no, jumping to the step (2), otherwise, executing the step (6);
(6) For an input secret message s, reading 1 byte of data y;
(7) Judging whether the y value is EOF or not;
(8) If the result in the step (7) is no, executing the step (9), otherwise, executing the step (12 b);
(9) For input coding table T k Look up T k The code word zz corresponding to the middle y value;
(10) Replacing the xx value in c obtained in the step (5) with the zz value in the step (9);
(11) Repeatedly executing the step (2);
(12a) And outputting the prompt information that the capacity of the carrier embedded is insufficient.
(12b) And outputting the changed c, namely the secret carrier c'.
3. Message extraction
The message extraction algorithm module of the present invention executes an extraction algorithm D (), which can be expressed as
m＝D(c′,T k′ )
Wherein, the module input parameter comprises a carrier c' with secret information and a coding table T generated by extracting a secret key k k′ The output of the module is the extracted secret message m. In particular, in order to maintain the coding table T k And T k′ The embedded key k and the extracted key k' are identical in the present invention.
The implementation flow chart of the extraction algorithm is shown in fig. 3, and the specific implementation steps are as follows:
(1) For the input carrier c', reading 2 bytes of data yy;
(2) Judging whether the yy value is EOF or not;
(3) If the result in the step (2) is no, executing the step (4), otherwise, executing the step (8);
(4) According to an input coding table T k′ Judging whether the yy value in the step (2) is T or not k′ The codeword of (1);
(5) If the result in the step (4) is no, jumping to the step (1), otherwise, executing the step (6);
(6) Lookup T k′ Obtaining an m value corresponding to the yy value;
(7) Repeatedly executing the step (1);
(8) Outputting the secret message m.
The above embodiments are only intended to illustrate the technical solution of the present invention and not to limit the same, and a person skilled in the art can modify the technical solution of the present invention or substitute the same without departing from the spirit and scope of the present invention, and the scope of the present invention should be determined by the claims.

Claims (6)

1. A method for hiding information by using invisible characters based on Unicode is suitable for hiding messages by using a text carrier containing invisible characters based on Unicode and comprises the following steps:
(1) Sending a protocol secret key of a sender and a receiver, controlling the generation of an encoding table through the secret key, and constructing the encoding table according to the secret key by using invisible characters in a Unicode code; controlling an encoding table T by a secret key k shared by a sender and a receiver k The step of constructing the coding table comprises the following steps:
(1-1) the key k must be a 2048 bit binary string, expressed in decimal form as:
n 0 n 1 …n i …n 255 ,n i ∈N∩[0,255],i＝0,1,…255，
furthermore, the component n of the key k i And n j The following conditions are satisfied:
the key k is expressed as a permutation of a sequence of integers from 0 to 255 as shown in the following formula:
k＝perms(0,1,2,…,255)，
where perms () is a permutation function;
(1-2) according to the characteristics of the Unicode code, a sender and a receiver find out selectable code words of 256 invisible characters in advance to serve as a construction basis of a code table shared by the sender and the receiver;
(1-3) according to step (1)1-1) and step (1-2), establishing a coding table T from the secret key to the optional code word k ；
(2) The sender selects text data based on Unicode coding as a carrier object, re-encodes invisible characters in the carrier object according to the coding table generated in the step (1), and embeds the secret message into the carrier object to obtain a carrier with secret;
(3) The sender transmits the carrier with secret obtained in the step (2) to a receiver through a communication channel;
(4) And (4) extracting the secret message from the carrier with the secret received in the step (3) by the receiver according to the coding table generated in the step (1) to obtain the secret message.
2. The method of claim 1, wherein: step (2) embeds the secret message into the carrier object by executing an embedding algorithm E (), represented as
c′＝E(c,m,T k )，
Wherein, the input parameters are carrier object c, secret message m to be embedded and coding table T generated by embedding key k k The output is the carrier with secret c' containing the secret message.
3. The method of claim 2, wherein: the carrier object c is text data based on Unicode encoding, and comprises TXT format text and text data in Word, PDF, XML and HTML compound documents; the secret message m is handled as a byte stream, and m is TXT text data or JPEG image data.
4. The method of claim 2, wherein the embedding algorithm is implemented by the steps of:
(2-1) preprocessing the input carrier object c, replacing c with 0x2000 for the code table T k The code word of (a);
(2-2) sequentially reading 2-byte data xx of c, and judging whether xx is 0x 00;
(2-3) if the result in the step (2-2) is no, executing the step (2-4), otherwise, executing the step (2-12 a);
(2-4) judging whether xx is an invisible character including a half-angle/full-angle space and a tab, and their corresponding Unicode code representations are 0x20, 0x00, and 0x0900, respectively;
(2-5) if the result in the step (2-4) is no, jumping to the step (2-2), otherwise, executing the step (2-6);
(2-6) reading 1 byte data y for the inputted secret message s;
(2-7) judging whether the y value is EOF;
(2-8) if the result in the step (2-7) is no, executing the step (2-9), otherwise, executing the step (2-12 b);
(2-9) encoding table T for input k Look up T k The code word zz corresponding to the middle y value;
(2-10) replacing the xx value in c obtained in step (2-5) with the zz value in step (2-9);
(2-11) repeatedly performing the step (2-2);
(2-12 a) outputting a notice that the capacity of the carrier embedding is insufficient;
(2-12 b) outputting the changed c, namely the secret carrier c'.
5. The method of claim 4, wherein: step (4) extracts the secret message from the secret carrier by executing an extraction algorithm D (), which is represented as
m＝D(c′,T k′ )，
Wherein, the input parameters are a carrier c' with secret information and a coding table T generated by extracting a secret key k k′ The output is the extracted secret message m; to maintain the coding table T k And T k′ The embedded key k is identical to the extracted key k'.
6. The method of claim 5, wherein the extraction algorithm is implemented by the following steps:
(4-1) reading 2 bytes of data yy for the input carrier c' with secret;
(4-2) judging whether the yy value is EOF;
(4-3) if the result in the step (4-2) is no, executing the step (4-4), otherwise, executing the step (4-8);
(4-4) encoding table T according to the input k′ Judging whether the yy value in the step (4-2) is T or not k′ The codeword of (1);
(4-5) if the result in the step (4-4) is no, jumping to the step (4-1), otherwise, executing the step (4-6);
(4-6) search for T k′ Obtaining an m value corresponding to the yy value;
(4-7) repeatedly performing the step (4-1);
and (4-8) outputting the secret message m.
CN201410733815.0A 2014-12-04 2014-12-04 Method using invisible character hiding information is encoded based on Unicode Active CN104504342B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201410733815.0A CN104504342B (en) 2014-12-04 2014-12-04 Method using invisible character hiding information is encoded based on Unicode

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410733815.0A CN104504342B (en) 2014-12-04 2014-12-04 Method using invisible character hiding information is encoded based on Unicode

Publications (2)

Publication Number Publication Date
CN104504342A CN104504342A (en) 2015-04-08
CN104504342B true CN104504342B (en) 2018-04-03

Family

ID=52945738

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410733815.0A Active CN104504342B (en) 2014-12-04 2014-12-04 Method using invisible character hiding information is encoded based on Unicode

Country Status (1)

Country Link
CN (1) CN104504342B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106301790B (en) * 2016-08-18 2019-11-15 中国联合网络通信集团有限公司 Confidential information exchange method, mobile terminal
CN107885704A (en) * 2016-09-29 2018-04-06 厦门雅迅网络股份有限公司 Text information hiding method and its system
CN106570356B (en) * 2016-11-01 2020-01-31 南京理工大学 Text watermark embedding and extracting method based on Unicode coding
CN107103630B (en) * 2017-03-03 2019-11-26 中国科学院信息工程研究所 A kind of carrier-free concealed communication method based on GIF attribute interval division mapping code
CN109657769B (en) * 2018-12-29 2021-11-19 安徽大学 Two-dimensional code information hiding method based on run length coding
CN111027080B (en) * 2019-11-26 2021-11-19 中国人民解放军战略支援部队信息工程大学 Information hiding method and system based on OOXML composite document source file data area position arrangement sequence

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1504044A (en) * 2001-06-12 2004-06-09 �Ҵ���˾ Method of invisibly embedding and hiding data into soft-copy text documents
CN1674055A (en) * 2004-07-26 2005-09-28 刘�东 Text digital water mark technology based on symbol redundancy encoding
CN101645061A (en) * 2009-09-03 2010-02-10 张�浩 Information hiding method taking text information as carrier

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6769061B1 (en) * 2000-01-19 2004-07-27 Koninklijke Philips Electronics N.V. Invisible encoding of meta-information
EP1396142B8 (en) * 2001-06-12 2005-06-08 International Business Machines Corporation Method of authenticating a plurality of files linked to a text document
CN1599405A (en) * 2004-07-26 2005-03-23 刘�东 Text digital watermark technology of carried hidden information by symbolic redundancy encoding
US20090285402A1 (en) * 2008-05-16 2009-11-19 Stuart Owen Goldman Service induced privacy with synchronized noise insertion
CN103761459B (en) * 2014-01-24 2016-08-17 中国科学院信息工程研究所 A kind of document multiple digital watermarking embedding, extracting method and device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1504044A (en) * 2001-06-12 2004-06-09 �Ҵ���˾ Method of invisibly embedding and hiding data into soft-copy text documents
CN1674055A (en) * 2004-07-26 2005-09-28 刘�东 Text digital water mark technology based on symbol redundancy encoding
CN101645061A (en) * 2009-09-03 2010-02-10 张�浩 Information hiding method taking text information as carrier

Also Published As

Publication number Publication date
CN104504342A (en) 2015-04-08

Similar Documents

Publication Publication Date Title
CN104504342B (en) Method using invisible character hiding information is encoded based on Unicode
CN105426709A (en) JPEG image information hiding based private information communication method and system
CN107561564B (en) A kind of compression implementation method of big-dipper satellite information transmission
CN103118139B (en) Distributed information hides transmission system and transmission method thereof
CN101729075A (en) Data compression method, data compression device, data decompression method and data decompression device
CN102724668A (en) Method and system for sharing WIFI (wireless fidelity) network information on basis of two-dimensional code graphs
Dai et al. Text Steganography System Using Markov Chain Source Model and DES Algorithm.
CN101964722A (en) Be used for method for communicating and system
US7177441B2 (en) System and method for secret communication
CN103532959A (en) Cross-platform network communication method
CN1937582B (en) Method for preprocessing data to be compressed and compressed data transmission method
CN103402185B (en) A kind of private information transfer method
CN102811426A (en) Method and system for cryptographically sending and receiving messages of mobile device
CN105959355A (en) Confidential information transmission method in P2P network based on BitTorrent protocol
CN108430091A (en) A kind of efficient smart home wifi distribution method and apparatus
CN105120012B (en) Smart machine and its networking cut-in method, message receiving method and device
CN103138871B (en) The server data processing system of application program and method in mobile communcations system
CN106254392A (en) Communication means based on the exTLV Message Protocol that dynamically can customize
CN111654484B (en) Ethernet workshop covert communication method based on whisper protocol
US8077868B2 (en) Mechanism for transport-safe codings for cryptographic use
CN104767710A (en) DFA (Determine Finite Automaton)-based transmission load extraction method for HTTP (Hyper Text Transfer Protocol) chunked transfer encoding
CN103178968A (en) Encryption method of data transmission threshold scheme based on Huffman compression
CN107534595B (en) Compression method and system for user-friendly addresses in mesh networks
CN108063828A (en) Network private communication channel building method based on the transmission of P2P files
CN105183750B (en) Close-coupled XML resolution system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant