CN100435591C - A method for transmitting invisible characters on a short message communication platform - Google Patents

Abstract

The invention discloses a method for realizing the transmission of invisible characters on a short message communication platform: firstly, a corresponding table of six-digit codes and visible characters is defined at both the communication sending end and the receiving end of the short message; the data to be transmitted (eight-digit codes) ) into a six-digit code; look up the corresponding table of the six-digit code and the visible character to find out the corresponding visible character; transmit the visible character to the control center through a short message SMS; the control center passes the received visible character through the six-digit code and the visible character Find out the corresponding six-bit code in the corresponding table; convert the six-bit code into the original data of eight-bit code through the inverse operation; through the above method, the problem of transmission of invisible characters is solved. In addition, the above method can also be used for visible characters , so that the original encoding is not transmitted during the transmission process, and at the same time, the problem of poor security of plaintext transmission is solved.

Description

A method for transmitting invisible characters on a short message communication platform

technical field

The invention relates to a method for transmitting characters through short messages, in particular to the transmission of invisible characters.

Background technique

The current SMS can only transmit visible characters, that is, only the characters in the range of 0X20~0X7F in the ASCII code table (0X00~0XFF) can be transmitted. When using SMS to transmit information in some fields such as GPS vehicle satellite positioning, some invisible characters are very important in the vehicle information. If only the visible characters are transmitted, the important invisible part of the information will be missed, making the information accurate. Sex cannot be guaranteed.

Contents of the invention

The purpose of the present invention is to propose a method for solving invisible character transmission.

The specific implementation method is:

A method for transmitting invisible characters on a short message communication platform: first define a correspondence table of six codes and visible characters at the communication sender and receiver of short messages; convert the data to be transmitted (eight codes) into Six-digit code; look up the corresponding table of six-digit codes and visible characters to find out the corresponding visible characters; transmit the visible characters to the information center through SMS; the information center will pass the corresponding table of six-digit codes and visible characters to the received visible characters Find out the corresponding six-bit code; convert the six-bit code into the original data of eight-bit code by inverse operation.

Described eight-bit coding adopts the following method to be converted into six-bit coding:

(1) Two zeros are added before every six bits of the eight-bit coded binary sequence;

(2) Separate a new group of numbers into a new byte every eight digits, and fill up eight digits with zeros if there are not enough eight digits.

The eight-bit coded data to be transmitted are invisible characters.

The eight-bit encoded data to be transmitted may also be visible characters.

Through the above method, after the invisible characters are coded and converted into six-digit codes, the first two digits of each six-digit code are zero, so the value of each six-digit code is within the range of 64 values from 0X00 to 0X3F According to the code conversion table (the values in the table are all visible characters), they are converted into visible characters and sent by SMS, which solves the transmission problem of invisible characters. In addition, the visible characters can also use the above method, so that the What is transmitted in the process is not the original code, and at the same time solves the problem of poor security of plaintext transmission.

Detailed ways

First, convert a set of vehicle information (binary data, eight-bit code) into six-bit code:

One byte (A) of binary data is represented like this:

A7, A6, A5, A4, A3, A2, A1, A0

The eight-bit encoding of ABCD... of a set of binary data is expressed as:

A7, A6, A5, A4, A3, A2, A1, A0, B7, B6, B5, B4, B3, B2, B1, B0, C7, C6, C5, C4, C3, C2, C1, C0, D7, D6, D5, D4, D3, D2, D1, D0...

Carry out six-bit encoding: that is, add two 0s in front of every six bits and use the new eight bits as a new byte. If the last byte is less than eight bits, fill up eight bits with 0, that is:

0,0,A7,A6,A5,A4,A3,A2//0,0,A1,A0,B7,B6,B5,B4//0,0,B3,B2,B1,B0,C7,C6/ /0,0,C5,C4,C3,C2,C1,C0//0,0,D7,D6,D5,D4,D3,D2//D1,D0...

After conversion, the first two bits of each byte are 0, so the value range of a byte is within the range of 64 values from 0X00 to 0X3F.

Correspond the last 6 digits b5~b0 of each byte (0, 0, b5, b4, b3, b2, b1, b0) after conversion with the visible characters in the preset code conversion table (below table), b5 , b4, b3 respectively correspond to the three positions of each group in the first column. b2, b1, b0 respectively correspond to the three positions of each group in the first row. The corresponding characters in the table can be any set of visible characters, so that a set of visible characters is formed through mapping.

000 001 010 011 100 101 110 111 000 2E 2C 30 31 32 33 34 35 001 36 37 38 39 41 42 43 44 010 45 46 47 48 49 4A 4B 4C 011 4D 4E 4F 50 51 52 53 54 100 55 56 57 58 59 5A 61 62 101 63 64 65 66 67 68 69 6A 110 6B 6C 6D 6E 6F 70 71 72 111 73 74 75 76 77 78 79 7A

Send the visible characters to the control center through SMS, and the control center will look up the code conversion table for the received data, convert it into a six-digit code, convert the six-digit code into the original binary data by the inverse operation of converting the six-digit code into the eight-digit code .

The present invention will be further described below in conjunction with specific example:

The data to be transferred is:

29 7f 10 70 01 11 31 33 34 80 ef e3 20 (hexadecimal)

Converted to binary as:

00101001 01111111 00010000 0111000 000000001 00010001 00110001

(29) (7f) (10) (70) (01) (11) (31)

00110011 00110100 10000000 11101111 11100011 0010000

(33) (34) (80) (ef) (e3) (20)

Converted to six-digit encoding as:

00001010 00010111 00111100 00010000 00011100 00000000

(0a) (17) (3c) (20) (2c) (00)

00000100 00010001 00001100 00010011 00001100 00110100 00100000

(04) (11) (0c) (13) (0c) (34) (20)

00001110 00111111 00100011 00001000 00000000

(0e) (3f) (23) (08) (00)

Check the conversion table to get the data:

38 4c 77 45 51 2e 32 46 41 48 41 6f 55 43 7a 58 36 2e

This data corresponds to the ASCII code table:

"8LwEQ.2FAHAoUCzX6"

The vehicle sends this text message to the control center, and the center obtains the data (29 7f 10 7001 11 31 33 34 80 ef e3 20) through inverse calculation. In this way, the problem of transmission of invisible characters is realized, and at the same time, what is transmitted during the transmission process is not the original code, which also solves the problem of poor security of plaintext transmission.

The method that aforementioned eight-bit encoding is converted into six-bit encoding can also adopt other existing encoding methods, and now give two examples as follows:

(1) 64 base method

Convert hexadecimal data to 64-ary data.

The 2 bytes of hexadecimal data are converted into 64 hexadecimal represented by 3 bytes.

For example: the hexadecimal string: 27 00 29 41 7f ea b6 is converted into 64 hexadecimal as follows:

Will fetch two bytes in sequence: 27 00

Its binary representation: 0010 0111 0000 0000

Its hexadecimal representation is: 02 28 00

Take out two more bytes: 29 41

Its binary representation: 0010 1001 0100 0001

Its hexadecimal representation is: 02 35 01

Take out two more bytes: 7f ea

Its binary representation: 0111 1111 1110 1010

Its hexadecimal representation is: 07 63 42

Take out two more bytes: b6 00 (there is only one byte left at this time, so add a byte 00)

Its binary representation: 1011 0110 0000 0000

Its hexadecimal representation is: 11 24 00

So the converted data is as follows: 02 28 00 02 35 01 07 63 42 11 24 00

(2) The method of multi-byte mixing

The method of converting 6 bytes into 8 bytes can be adopted. If the number of data is not a multiple of 6, you can add 0 to make it a multiple of 6.

If there is the following data: 45 23 3e fe 40 00

The binary representation is as follows: 0100 0101

0010 0011

0011 1110

1111 1110

0100 0000

0000 0000

Take the data according to the same position of each binary data and add two 0s in front to get 8 bytes:

00 000100(04)

00 100110(26)

00 011100(1c)

00 001100(0c)

00 001100(0c)

00 101100(2c)

00 011100(1c)

00 110000(30)

Claims (2)

1. A method for transmitting invisible characters on a short message communication platform, characterized in that: first define a corresponding table of six-bit codes and visible characters; convert the invisible character data of eight-bit codes to be transmitted into six-bit codes ;Look up the corresponding table of six-digit codes and visible characters to find out the corresponding visible characters; transmit the visible characters to the control center through SMS; Six-bit code; the six-bit code is converted into eight-bit coded invisible character data by inverse operation. 2. A method for transmitting invisible characters on a short message communication platform as claimed in claim 1, characterized in that: said eight-bit code adopts the following method to convert into six-bit code: (1) Two zeros are added before every six bits of a group of eight-bit coded binary sequences; (2) Separate a new group of numbers into a new byte every eight digits, and fill eight digits with zeros if there are not enough eight digits.