WO2008086731A1

WO2008086731A1 - Method and system of encrypt by using chaotic cipher stream

Info

Publication number: WO2008086731A1
Application number: PCT/CN2008/000040
Authority: WO
Inventors: Shu Tak Raymond Lee
Original assignee: Shu Tak Raymond Lee
Priority date: 2007-01-05
Filing date: 2008-01-07
Publication date: 2008-07-24
Also published as: CN101216868A

Abstract

A method and a system of the encrypt by using the chaotic cipher stream to encrypt, in which the method includes encrypting by operating the chaotic cipher stream generated with the clear text data, and decrypting through XOR operating between the cipher text data with the said chaotic cipher stream. The encrypting method depends completely upon the initial parameter, thus it is more difficulty to be decrypted as the person who engages illegal decrypting doesn't know the initial parameter.

Description

Method and system for applying chaotic cipher stream encryption

The present invention relates to data processing and, more particularly, to a method and system for applying chaotic cipher stream encryption. Background technique

The cryptosystem encrypts the original information and decrypts the encrypted information based on mathematical principles. The present invention uses a new mathematical principle, a chaotic principle. The chaotic encryption method is widely used in the field of communication. It is a set of nonlinear dynamic equations controlled by one or more parameters; therefore, the chaotic state changes according to the subtle changes of the parameters and is sensitive to the initial state. The chaotic systems that people can access every day include: water flowing out of taps, angry smoke in cigarettes, rising and falling stock markets, and musical melody.

In the future, this method can also be implemented in asymmetric encryption. In fact, the chaotic cryptosystem is

One of the main information of the IATOPIA cryptosystem. With the support of Intelligent Agent Technology (IAT), the deeper interpretation of the IATOPIA cryptosystem is copyright protection technology (CPT). Summary of the invention

The technical solution adopted by the present invention to solve the problems existing in the prior art is to provide a method for applying encrypted cipher stream encryption, which includes the following steps:

51. The random number generator generates a symmetric key and stores it in a memory;

52. Chaotic mapping of generated symmetric key values to generate chaotic values;

53. Round the chaotic value and reverse part of the chaotic value;

54. Combine the chaotic values into a virtual key;

55. The plaintext and the virtual key are operated to obtain a ciphertext.

According to another aspect of the present invention, a method for applying chaotic cipher stream decryption is provided, comprising the steps of:

1 Confirmation 51. Chaotically mapping the symmetric key value to generate a chaotic value;

52. Round the chaotic value and invert the partial chaotic value;

53. Combine the chaotic values into a virtual key;

54. The ciphertext and the virtual key are operated to obtain plaintext.

According to another aspect of the present invention, a system for chaotic cipher stream encryption is provided, comprising the following means:

a random number generating device that generates a symmetric key;

a memory for storing a symmetric key generated by the random number generating device;

a chaotic mapping device that generates a chaotic map of symmetric key values to generate chaotic values; a transforming device that rounds the chaotic values and reverses partial chaotic values;

Combining the chaotic values into a key generation device that constitutes a virtual key;

The ciphertext encryption device is obtained by calculating the plaintext and the virtual key.

According to another aspect of the present invention, a system for chaotic cryptographic stream decryption is provided, comprising the following means:

a chaotic mapping device that performs chaotic mapping on a symmetric key value in a memory to generate a chaotic value; a conversion device that rounds the chaotic value and reverses a partial chaotic value;

The ciphertext and the virtual key are operated to obtain a plaintext decryption device.

The encryption method of the present invention is completely dependent on the initial parameters and, therefore, is more difficult to decrypt if the illegal decryptor does not know the initial parameters. Moreover, the method and system proposed by the present invention are also applicable to any field requiring encryption.

DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

Figure 1 is a block diagram of an encryption system of the present invention;

Figure 2 is a block diagram of the decryption system of the present invention;

3 is a flow chart of applying chaotic cipher stream encryption according to the present invention;

4 is a flow chart of the application of chaotic cipher stream decryption in the present invention.

detailed description 1 is a block diagram of an encryption system of the present invention. As shown in FIG. 1, the encryption system of the present invention includes a memory 102, a random number generating device 101 that generates and stores a symmetric key, and chaotic mapping of the generated symmetric key values to generate a chaotic value chaotic mapping device 103. The conversion device 104 that chases the chaotic value and reverses the partial chaotic value, merges the chaotic value into the key generation device 105 that constitutes the virtual key, and performs the encryption operation on the plaintext and the virtual key to obtain the ciphertext encryption. Device 106.

2 is a block diagram of a decryption apparatus of the present invention. As shown in FIG. 2, the decryption system of the present invention includes a chaotic mapping device 201 that performs chaotic mapping of symmetric key values in a memory to generate chaotic values, truncating the chaotic values, and inverting partial chaotic values. The converting means 202 combines the chaotic values into a key generation means 203 which constitutes a virtual key, and operates the ciphertext and the virtual key to obtain a plaintext decryption means 204.

3 is a flow chart of applying chaotic cipher stream encryption according to the present invention. The encryption process is described in detail in conjunction with Figure 1. Step 300, the random number generating means 101 generates a symmetric key k, which may be of variable length. In the present embodiment, a length of 32 bytes is used, and the key k stores an ASCII value of 0 to 255. storage. In step 305, the symmetric key k is stored in the database 102 for decryption processing. In step 310, the key value k is placed in the chaotic mapping device, and after the chaotic mapping is performed multiple times, a chaotic value is generated. Step 315, the chaotic value is truncated by the conversion device 104 to an integer value, for example, 0.12345 is truncated to 12345, and some chaotic values are reversed by the conversion device 104, for example, 12345 is inverted to 54321. Step 320: The key generation device combines all the chaotic values into a virtual key S, for example, 12345.54321, etc. to form 1234554321.... The length of the S value varies according to different symmetric keys. Step 325, the plaintext P is read into the encryption device 106. In step 330, the plaintext P and the virtual key S perform operations multiple times, for example, an exclusive OR operation to ensure randomness of the encrypted text, where the encrypted information C is generated.

The key k is a symmetric key with a certain number of bytes, and each byte includes an ASCII value of 0 to 255 (hexadecimal value 00 to FF). The key is used to place a logarithmic map to produce a value for future encryption/decryption processing.

The chaotic value (d _n ) is the resulting value of the chaotic map inserted into k _n .

^ is the fractional part of ^, the integer part is truncated, and then the fractional part is reversed.

P is plaintext, that is, information before encryption.

C is ciphertext, that is, encrypted information. Chaotic mapping is a core part of cryptography. Select the logarithmic map as follows: x _n+1 ^{= a} ' x _n ' (l - x _n )

a is a parameter of the logarithmic mapping, because the branching property of the logarithmic mapping multiplies the mapping period to become chaotic, so a is usually set to be greater than 3.

The value of X is set to 0 to 1.

n represents the nth repetition within the logarithmic map, the number of repetitions is variable, and is usually set to be greater than

100.

Not only is logarithmic mapping available to the core of the encryption/decryption technique of the present invention, but any other type of chaotic mapping can be used in the core portion of the cryptographic technique of the present invention. The reason for using logarithmic mapping here is that this equation is simple, does not require too many computational resources, but the results are complex. The processing in the present invention finds a balance between the randomness of ciphertext and the speed of encryption/decryption processing.

The exemplary encryption source code is as follows: '

II version 3.1

II chaotic coding of variable key length

II write out the key separation file

Package enc;

Import java.io.*;

Import java.util.*;

Import java.text.*;

Import java.lang.*; import sun.misc.BASE64Decoder;

Import sun.misc.BASE64Encoder; public class CEncrypt_file02

{

II Management Data Document

FilelnputStream dataFisOl ; BufferedlnputStream dataFis;

II key document

FileOutputStream kfileOl;

BufferedOutputStream kfile;

II encrypted document

FileOutputStream defileOl ;

BufferedOutputStream defile;

Final int KEY_SIZE = 32;

Final int MSG_SIZE = 16;

Byte load_key[] = new byte [KEY_ SIZE];

Private String chaosstring = "";

Byte map—key port;

File key— file— name;

Private String ftiame = "";

Private String fext = "";

Public CEncrypt_file02(File filename, File dirname) {

II snoring key documents and text documents

If (filename == null || filename. equals(" "))

{

System.err.println("Invalid Source Path File Name"); Return;

}

Else if (dirname null || dirname.equals(""))

{

System. err.println(" Invalid Destination Path Name");

Return;

}

Else

{

Try

{

IIOpen the input text document and create an output text document

dataFisOl = new FilelnputStream(fllename);

dataFis = new BufferedInputStream(dataFisO 1 );

II Get the document name and extension, and add trailing spaces

String tt = filename.getName();

Fhame = tt.substring(0, tt.lastIndexOf(".")); fext = tt.substring(tt.lastIndexOf(" . ")+ 1 );

Int num_sp = 5-fext.length();

For (int i = 0; i < num_sp; i++)

{

Fext = fext + " ";

}

II Establish a key document

File key— output = new File(dirname + "\\" + fhame + ".ckl"); kfileOl = new FileOutputStream(key_output); Kfile = new BufferedOutputStream(kfile01 ); byte port strKey = KeyGenerator();

For(int i = 0; i < KEY— SIZE; i++)

{

writeBuffer02(strKey[i]);

}

Form— key ();

/ / Create an output document

File encrypt_ output = new File(dirname +"\\" + fhame + " ef); defileOl ^ new FileOutputStream(encrypt_output);

Defile = new BufferedOutputStream(defile01 );

II extended file encryption

Byte port fx = fext.getBytes();

For(int i = 0; i < fx. length; i++)

{

writeBuffer(xor_opt(i, fx[i]));

}

II read the original document content

Int intCount = 5;

Int fcontent;

While ((fcontent = dataFis.readQ) != -1) writeBuffer(xor_opt(intCount-3, xor_opt(intCount-5, xor_opt(intCount _:) fcontent))));

intCount++;

Defile. flush();

defileOl.flushO; dataFis.close();

Defile.close();

Kfile.close();

dataFis01.close();

Defile01.close();

kfileOl.closeO;

}

Catch (lOException ioException)

{

System. out.println("ioException " + ioException);

Return;

}

II encrypts documents using a specific key stream

Public CEncrypt_file02(File filename, File dimame, String key) {

II Open key document and text If (filename = null || filename. equals(""))

{

System.err.println("Invalid Source Path File Name"); return;

}

Else if (dirname == null || dirname.equals(""))

{

System. err.println(" Invalid Destination Path Name"); return;

}

Else {

Try {

II Open the input text document and create an output text document dataFisOl = new FilelnputStream(filename); dataFis = new BufferedInputStream(dataFisO 1);

II Get the document name and extension, and add a trailing space String tt = filename.getName();

Foame = tt.substring(0, tt.lastIndexOf(" . ")); fext = tt.substring(tt.lastIndexOf(".")+l); int num_sp = 5-fext.length();

For (int i = 0; i < num_sp; i++)

{

Fext = fext + " ";

} II Establish a key document

/*

File key - output = new File(dimame +"\\"+ fhame + ".ckl"); kfileO 1 = new FileOutputStream(key_output);

Kflle■= new BufferedOutputStream(kfile01 );

Byte[] strKey = KeyGenerator();

For(int i = 0; i < KEY— SIZE; i++)

{

writeBuffer02(strKey[i]);

}

*/

BASE64Decoder decoder = new BASE64Decoder();

Load— key = decoder. decodeBuffer(key);

Form_key();

II establish an output document

File encrypt_ output― new File(dirname +"\\" + fhame + ".cef ); defileOl = new FileOutputStream(encrypt_output);

Defile = new BufferedOutputStream(defile01 );

II extended encryption of documents

Byte port fx = fext.getBytes();

For(int i = 0; i < fx.length;

{

writeBuffer(xor_opt(i, fx[i]));

} II read the source document content

Int intCount = 5;

Int fcontent;

While ((fcontent = dataFis.read()) != -1)

{ miteBuffer(xor_opt(intComit-3,xor_opt(intCount-5,xor_opt(intCount. fcontent))));

intCount++;

} defile.flush();

defileOl.flushO;

dataFis.close();

Defile.close();

//kfile.close(); -

dataFis01.close();

Defile01.close();

//kfileOLcloseO;

}

Catch (lOException ioException) {

System.out.println("ioException " + ioException);

Return;

} }

}

II generating a key

Public byte port KeyGenerator()

{

Int intKeyGen[] = new int[KEY_SIZE]; for (int n = 0; n < KEY- SIZE; n++)

{

intKeyGen[n] = new j ava.util . Random() .nextlnt(256);

Load_key[n] = (byte) intKeyGen[n];

//System.out.println("load_key[" + n + "] =" + load- key[n]);

}

Return load— key;

}

II generates a random key

Public static String genKey(){

Final int KEY_SIZE=32;

Byte key[] = new byte [KEY_SIZE];

String keytxt = new String(); int int eyGen[] = new int[KEY— SIZE]; for (int 11 = 0; n < KEY— SIZE; n++)

{

intKeyGen[n] = new j ava . util . Random() .nextlnt(256); key[n] = (byte) intKeyGen[n]; //System.out.println("load_key[" + n + "]- ' + load-key[n]);

}

II return load-key;

System. out.println(new String(key));

BASE64Encoder encoder64 = new BASE64Encoder();

Keytxt = encoder64.encode(key);

Return keytxt;

}

II generates a key using the given username in the key

Public static String genKey(String str) {

Final int KEY_SIZE=32;

Byte key port = new byte[KEY_ SIZE];

String keytxt = new String();

Int intKeyGen[] = new int[KEY_SIZE];

For (int n = 0; n < KEY_SIZE-str.length(); n++) {

intKeyGen[n] = new java.util.Random().nextInt(256);

Key[n] = (byte) intKeyGen[n];

//System.out.println("load_key[" + n + "]- ' + load_key[n]);

}

Int count = 0;

For (int n = KEY_SIZE-str.length(); n < KEY— SIZE;n++){ key[n] = (byte)((int)str.charAt(count) + 32);

Count++;

}

II return load-key; System. out.println(new String(key));

BASE64Encoder encoder64 = new BASE64Encoder(); keytxt = encoder64. encode(key);

Return keytxt;

}

II Enter the key value from the chaotic key for encryption

II if the encrypted document cannot be decrypted

II may be a floating point error when the key is passed to the logarithmic map

Private void form— key() {

II Enter the key into the logarithmic map and generate a small value

For (int i = 0; i < KEY- SIZE; i++)

{

Double nvalue = calc_opt(i);

String nsvalue = Double.toString(nvalue);

Nsvalue = nsvalue.substring(nsvalue.lastIndexOf(".")+l);

StxingBuffer sb = new StringBuffer();

Sb . append(nsvalue);

Nsvalue = sb.reverse().toString();

Chaosstring = chaosstring + nsvalue;

}

Int ct = (int) Math.ceil((double) chaosstring.length()/2);

Map— key = new byte[ct];

Int subct=0;

Int subct—ed = 2;

For (int i = 0; i <ct; i++) {

If (subct_ed > chaosstring.length())

{

Subct—ed--;

}

String tp = chaosstring.substring(subct, subct-ed); map— key[i] = Byte.parseB te(tp);

If(i % 2 == 0)

Map_key[i] = (byte) (255 - map_key[i]);

Else

Map—key [i] = map— key [i];

System.out.println("map_key["+i+"]

Subct+=2;

Subct ed+=2:

Private double LogisticMap(int k)

{

Double b = 3.78;

Double lm = ( (double) k / 512);

For (int loop = 0; loop < k; loop++)

{

Lm = b * lm * (1 - lm);

Return Math.abs(lm); }

II Add noise to management data

Private double calc_opt(int loop— count)

II Execute XOR operation on document content

Private byte xor— opt (int loop— count, int pvalue)

Convert to binary and output the document

Private void writeBuffer(byte s)

II output key document

Private void writeBuffer02(byte s)

FIG. 4 is a flow chart of decrypting information by the document reading module of the present invention. Step 405, the key value is placed in the chaotic mapping device 201, and after the chaotic mapping is performed multiple times, a chaotic value is generated. In step 410, the chaotic value is truncated by the converting means 202 to an integer value. For example, 0.12345 is truncated to 12345, and some chaotic values are reversed by the converting means 202, for example, 12345 is inverted to 54321. Step 415, the key generation means 203 combines all the chaotic values into a virtual key S, for example, 12345, 54321, etc. to constitute 1234554321.... The length of the S value varies according to different symmetric keys. In step 420, ciphertext C is read into the memory. Step 425, the encrypted information C and the virtual key S perform operations multiple times, for example, XOR operations to generate original information. .

The exemplary decryption source code is as follows:

II version 3.1

II chaotic decryption of various key lengths

II read from separate document input

Package enc; Import java.io.*;

Import java.util.*;

Import java.text.*;

Import java.lang.*; import sun.misc.BASE64Decoder; public class CDecrypt_file02 {

//Initialize variables

FilelnputStream infileOl; II encrypted data input stream

BufferedlnputStream infile;

FilelnputStream kfileO 1; II key input stream

BufferedlnputStream kfile;

FileOutputStream defileOl;

BufferedOutputStream defile; final int KEY— SIZE = 32;

Final int MSG— SIZE = 16; byte load—key port = new byte [KEY— SIZE];

Private String chaosstring = "";

Byte map_key[];

String strKey = "";

Public String ihame = "";

Public String fext = ""; public CDecrypt_file02(File filename, File key- file, File dimame)

{ II Open key document and text document

If (filename == null || filename. equals(""))

{

System.err.printlnC'Invalid Source File Path Name");

//System.exit(l);

Return;

}

Else if (dirname == null || dirname.equals(""))

{

System.err.printlnC'Invalid Destination Path Name"); return;

//System.exit(l);

}

Else

{

Try

{

II uses the management document name as the decrypted document name

String tt = filename.getName();

Fname = tt.substring(0, tt.lastIndexOf(" . "));

II open key document

kfileOl = new FileInputStream(key_file);

Kfile = new BufferedInputStream(kfileO 1 );

II read the key from keyjile

Kfile.read(load_key);

Form_key(); IIOpen the input text document and create an output text document

infileOl = new FilelnputStream(filename); II open text file

Infile - new BufferedInputStream(infileO 1 );

II read the source document content

Int char ct = 0;

II document extension

String fext =

Byte[] cext = new byte [5];

Infile. read(cext);

For (int i = 0; i < 5; i++)

{

Fext = fext + (char) xor_opt(i, cext[i]);

}

II decrypt document path and name

File fileOut = new File(dirname + "\\" + fhame + "." + fext.trim()); defileOl = new FileOutputStream(fileOut);

Defile = new BufferedOutputStream(defile01 );

II read the source document content

Int intCount = 5;

Int rem = 0;

Int fcontent;

While ((fcontent = infile. read()) != -1) { writeBuffer(xor_opt(intCount, xor_opt(intCount-5, xor_opt(intCount-3, fcontent))));

intCount++;

} defile. flush();

defileOl.flushO;

Infile.close();

Defile. close();

Kfile.close();

Infile01.close();

Defile01.close();

Kfile01.close();

}

Catch (IOException ioException)

{

//System. out.println(" ioException " + ioException.getMessage()); ioException.printStackTrace();

//System.exit(l);

Return;

}

Public CDeci-ypt_file02(File filename, String key, File dimame) II Open the key document and text document if (filename == null || filename.equals("")) {

System.err.printlnC'Invalid Source File Path Name"); return;

//System.exit(l);

}

Else if (dimame == null || dimame. equals(""))

{

System.err.printlnC'Invalid Destination Path Name"); return;

//System.exit(l);

}

Else {

Try {

II uses the management document name as the decrypted document name

String tt = filename . getName();

Fname = tt.substring(0, tt.lastIndexOf("."));

II open key document

/*

kflleOl = new FileInputStream(key_file);

Kfile = new BufferedInputStream(kfileO 1 ); II reads the key from the key file

Kfile.read(load_key);

*/

BASE64Decoder decoder = new BASE64Decoder();

Load— key = decoder.decodeBuffer(key);

II Open the input text document and create an output text document infileOl = new FilelnputStream(filename); II open text file infile = new BufferedInputStream(infileO 1 );

II read the source document content Read source file content int char ct = 0;

/ / Document extension

String fext = "";

Byte[] cext =■ new byte [5];

Infile.read(cext);

For (int i = 0; i < 5; i++)

{

Fext = fext + (char) xor_opt(i, cext[i]);

}

II decrypt document path and name

File fileOut = new File(dirname + "\\" + fi ame + "." +

defileOl = new FileOutputStream(fileOut);

Defile = new BufferedOutputStream(defile01 ); ppO;e ioExction.rntStackTirace

Yp(ppggo); //ss.otemut.rointlniExcetnio iocoExetin.etMessae +" - (pp)athO cclExcetion ioExceti>on O;/ /kfileOl.close

o;oo dejsel.clse

O; ifeO.closnille o; //oskfileble

o; denosle.cle

o; infileblose o; defleousllh

o; defue.fhlsh ; intcount++

)))); fcontent

(—p(lp(3⁄4lp(,, wuiteBfferxorotcointtroticontunt5oxr.tintcount3--

((O)) whilefcontent infile.read T1 = - ; int fcontent ;n it intcount 5H Return;

//System.exit(l);

}

II from the chaotic key input key value used as encryption

Private void form_key()

{

For (int i = 0; i < KEY- SIZE; {

Double nvalue = calc_opt(i);

String nsvalue = Double.toString(nvalue);

Nsvalue = nsvalue. substring(nsvalue.lastIndexOf(".")+l);

StringBuffer sb = new StringBuffer();

Sb.append(nsvalue);

Nsvalue = sb.reverse().toString();

Chaosstring = chaosstring + nsvalue;

}

Int ct = (int) Mat .ceil((double) chaosstring.length()/2);

Map— key = new byte[ct];

Int subct=0;

Int subct—ed = 2;

For (int i = 0; i < ct; i++)

{

If (subct_ed > chaosstring.lengt ()) {

Subct__ed~;

}

String tp = chaosstring.substring(s bct, s bct_ed); map_key[i] = Byte.parseByte(tp);

If (i % 2 == 0)

Map_key[i] = (byte) (255 - map— key[i]);

Else

Map— key [i] = map_key[i];

System.out.println("map-key["+i+"]="+map-key[i]); subct+=2;

Subct_ed+=2;

}

II Enter the key value, limited to a value of 0->1,

II runs the logarithmic map k times, the return result is multiplied by the key value

Private double LogisticMap(int k)

Private double calc_opt(int loop— count)

II document XOR operation

Private byte xor— opt (int loop— count, int pvalue)

II converts to binary data and outputs the document

Private void writeBuffer(byte s)

Claims

Rights request

A method for applying chaotic cipher stream encryption, characterized in that it comprises the following steps:

51. Randomly generate a symmetric key and store it in memory; mentioned in right 2

52. Chaotically map the symmetric key generated by S1 to generate a chaotic value;

53. Round the chaotic value and reverse the partial (how to determine) chaotic value; (plus one step to write the reverse)

54. Combine the truncated (in the right interpretation) and reverse chaotic values in S3 into a virtual key;

55. The plaintext (interpretation) and the virtual key are operated to obtain the ciphertext. (from the right to explain the merger)

2. A method for applying chaotic cipher stream decryption, characterized in that it comprises the following steps:

51. Chaotic mapping of symmetric key values to generate chaotic values;

52. Round the chaotic value and reverse the chaotic value;

53. Combine the chaotic values into a virtual key;

54. The ciphertext and the virtual key are operated to obtain a plaintext.

3. A system for chaotic cipher stream encryption, characterized in that it comprises the following means:

a random number generating device that generates a symmetric key;

4. A system for chaotic cryptographic stream decryption, characterized in that it comprises the following means: