JP2006191385A - Mobile phone device and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a communication apparatus and a communication system having simple constitution and capable of preventing transmitting/receiving data from being easily intercepted. <P>SOLUTION: A mobile phone device is provided with: a means for preparing mail information; a collation means for collating information of a transmission destination which is included in the prepared mail information with preset information; a cipher key generation means for generating a cipher key when the transmission destination information included in the mail information coincides with the preset information; an encryption means for encrypting the mail prepared by the preparation means on the basis of the generated cipher key; and a transmission means for transmitting the mail information encrypted by the encryption means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile phone device having a mail receiving function, and more particularly to a mobile phone device and a communication system that encrypt and display mail received from a specific sender.

  In recent years, communication terminal devices such as mobile information terminals and mobile phones have been widely used. Especially, mobile phones have become one era per person due to a decrease in call charges and body prices, and are already essential among young people. It is an item.

  In addition, in these communication terminal devices, in addition to the call function that is the basic function, each telecommunications carrier competes and commercializes in a short time what has an e-mail function for transmitting and receiving text data and various files and an Internet connection function. The performance and functions are being improved one after another.

  In particular, the e-mail function is used by many users because the requirements can be easily sent by e-mail created with characters, symbols, pictograms, etc., regardless of whether the other party can talk. Recently, telecommunications carriers are trying to acquire customers because they want to flatten packet communications.

  On the other hand, the e-mail function has the advantages as described above, but many e-mails are received without knowing to the receiver, and the importance of each e-mail is not known to the sender. However, there is a problem that it is difficult to get a reply from the recipient if the mail is opened in the order of arrival even though the importance is high.

  For these problems, it is known to determine the importance level of received email based on the rules regarding the importance level set in advance by the user, and to display the email headline list in a display method according to the importance level. (For example, refer to Patent Document 1).

In addition, although mail information is often used as a general communication means, it is necessary to pay attention to the protection of privacy because it is an information transmission means between individuals. In response to such a request, conventionally, a method of locking an email has been proposed. In this method, when a user enters a mailbox, a lock number is requested from the operator of the mobile phone, and when the lock number matches, the mail is unlocked and its contents are displayed. In addition to these methods, a method has been proposed in which a specific mail is not displayed in the mailbox list unless a special operation is performed.
Japanese Patent Laid-Open No. 9-200254

  Although there is a technology that prevents others from looking into the email content due to the lock number in this way, with such technology, there is nothing about sending the created email text and intercepting this email text by a third party No measures are taken.

  Moreover, it is easily intercepted by a third party simply by modulating and sending the mail text. That said, building a complex encryption system is costly and impractical.

  In view of the above circumstances, the present invention provides a mobile phone device and a communication system that encrypts the mail text based on the telephone numbers of the transmission side and the reception side, that is, cannot be decrypted by a third party with a simple configuration. The purpose is that.

The invention according to claim 1 is a means for creating e-mail information having destination information and an e-mail text, and a collating means for collating the destination information included in the created e-mail information with preset information. The destination information included in the mail information matches the preset destination information, the encryption key generating means for generating an encryption key, and the creating means based on the generated encryption key. An encryption means for encrypting the created mail body and a transmission means for transmitting the mail body encrypted by the encryption means are provided.
The invention according to claim 2 is provided with a data table for associating and storing a mail address and a telephone number, and when the mail address included in the mail information to be transmitted exists in the data table, the encryption key generating means The encryption key is generated from the telephone number of the sender and the telephone number of the receiver.
The invention described in claim 3 is characterized by further comprising decryption means for decrypting the encrypted mail body using the encryption key.
According to a fourth aspect of the present invention, there is provided a transmitting terminal that encrypts and transmits character data using a transmitting telephone number and a receiving telephone number, and the transmitting terminal includes a transmitting telephone number and a receiving telephone number. And a receiving terminal that decrypts the encrypted character data received from the communication system.

  According to the first aspect of the present invention, there is provided means for storing destination information at the time of transmission and mail information having a mail body, destination information included in the stored mail information, and preset destination information. Based on the generated encryption key, the encryption key generating means for generating the encryption key when the destination information included in the mail information matches the preset destination information, And an encryption means for encrypting the mail text stored in the storage means, and a transmission means for transmitting the mail text encrypted by the encryption means.

  According to the second and third aspects of the invention, since the mail information is encrypted based on the telephone numbers of the mail transmission side and the reception side, the mail information can be encrypted with a simple configuration. Even if the mail information is intercepted by the three parties, it is possible to prevent the encryption from being easily decrypted.

  In the invention according to claim 4, since it is possible to construct a communication system that is not easily deciphered even if a third party intercepts character data with a simple configuration, it is possible to increase the cost of the apparatus by providing a complicated encryption apparatus. Can be avoided.

  Next, a mobile phone device according to an embodiment of the present invention will be described with reference to the drawings.

  First, an outline of the apparatus of this embodiment will be described.

  FIG. 1 is a system block diagram showing an outline of the present embodiment.

  In FIG. 1, there are a mobile phone device 100 on the transmission side and a mobile phone device 200 on the reception side. Each of the mobile phone devices 100 and 200 includes a mail text storage unit 110 and 210, a cipher generation unit 120, a decryption unit 220, an encoder unit 130, a decoder unit 230, and radio units 140 and 240.

  In the mobile phone device 100 on the transmission side, the mail text storage unit temporarily stores the text data of the created mail. The encryption key generation unit includes the last four digits of the telephone number of the transmission side (for example, the mobile phone 100) and the reception side (for example, the mobile phone 200), and the mail text stored in the mail text storage unit. By taking an exclusive OR with the character data, the character data of the encrypted mail body is generated.

  The encoder unit encodes the encrypted mail body data (binary data) by character conversion using BASE64 (details will be described later).

  The encoded mail text data is modulated by the wireless unit and transmitted wirelessly.

  On the other hand, in the mobile phone device 200 on the receiving side, the radio unit receives and demodulates the radio signal transmitted from the mobile phone device 100. The demodulated signal is decoded by character conversion using BASE64 in the decoder unit, and the decoded binary data is transmitted by the decryption unit at the transmission side (for example, the mobile phone 100) and the reception side (for example, the mobile phone 200). Is exclusive ORed with the last four digits of the phone number, and the cipher is decrypted and stored in the mail storage unit. Further, the data of the mail text stored in the mail storage unit can be displayed on the display unit in accordance with a user operation.

  In the present embodiment, the data of the mail text is encrypted and transmitted based on the telephone numbers of the transmission side and the reception side. For this reason, it is difficult to view the mail text even if the data of the mail text is intercepted by a third party when the mail text is transmitted wirelessly.

  Note that the encryption generation unit 120, the encoder 130, the decryption unit 220, and the decoder 230 in FIG. 1 are mounted inside the control circuit 36 shown in FIG.

  Next, the cellular phone device which is the device of this embodiment will be described in detail.

As shown in FIG. 2, the mobile phone device 10 according to the embodiment of the present invention includes a communication unit (reception unit) 12, a baseband unit 14 including a CDMA processing circuit 18 and an audio codec 20, an antenna 16, Switching circuit 22, amplifier circuits 24, 28, 32, first speaker 26, microphone 30, second speaker 34, control circuit (matching means) 36, ROM 38, RAM (data table) 40, The display unit 42 includes a display 42 (display unit), an illumination unit 46, a numeric keypad 48, a call key 50, an off key 52, and an input unit (input unit) 44 including function keys 54.
The communication unit 12 converts a transmission signal in an intermediate frequency band output from a baseband unit 14 to be described later into a radio frequency band, and transmits this signal to the base station via the antenna 16 or receives it via the antenna 16. The radio signal from the base station is converted to an intermediate frequency band and output to the baseband unit 14. In the present embodiment, an e-mail address, e-mail information, etc. are received from the transmission side terminal and output to the baseband unit 14.

  The CDMA processing circuit 18 constituting the baseband unit 14 performs processes such as code division multiple access, scrambling, error control, and timing detection. The audio codec 20 performs compression processing (encoding) and expansion processing of audio data, or converts an analog signal into a digital signal and a digital signal into an analog signal. In addition, the amplification level of an internal amplifier circuit (not shown) is varied to amplify or attenuate the received sound volume and change the microphone sensitivity.

  The switching circuit 22 is connected to the first speaker 26 via the amplifier circuit 24. The first speaker 26 outputs the electrical signal from the baseband unit 14 amplified by the amplifier circuit 24 to the outside as an audio signal. The first speaker 26 is used for a call by being applied to the user's ear.

  The switching circuit 22 is also connected to the microphone 30 via the amplifier circuit 28. The microphone 30 is used for a telephone call, and converts the collected sound signal into an electric signal. The electrical signal output from the microphone 30 is amplified by the amplifier circuit 28 and output to the baseband unit 14.

  The switching circuit 22 is also connected to a second speaker 34 via an amplifier circuit 32. The second speaker 34 outputs an electrical signal input from the baseband unit 14 amplified by the amplifier circuit 32 to the outside as an audio signal. The second speaker 34 is a loudspeaker for listening to the surrounding people to the received sound. The second speaker 34 also sounds an incoming call notification. The gains of these three amplifier circuits 24, 28, and 32 are fixed, and the volume of the first speaker 26 and the second speaker 34 and the sensitivity of the microphone 30 cannot be changed.

  The switching circuit 22 is connected to the base circuit unit 14 on the side of the amplifier circuit 24 for the first speaker 26 and the amplifier circuit 28 for the microphone 30, or the amplifier circuit for the second speaker 34 for loud sound. 32 and the amplifying circuit 28 side for the microphone 30 are switched.

  The control circuit 36 performs all control of the cellular phone device such as control necessary for a call (for example, control of location registration, standby, link establishment, handover, etc.) and display control. In the present embodiment, the telephone number on the sender side is searched based on the mail address in the mail information received from the data table stored in the RAM 40, and when the telephone number is in the data table, the telephone number The number is output to the encryption unit 43. Also, transmission / reception control, telephone number notification control, telephone number storage control, and the like are performed. Further, the switching control of the switching circuit 22 and the audio coding 20 in the baseband unit 14 are controlled, and the volume of the first speaker 26 and the second speaker 34 and the sensitivity of the microphone 30 are controlled.

The control circuit 36 also encrypts / decrypts the mail body from the telephone numbers of the transmitting side and the receiving side, encodes the encrypted binary data using BASE64, and receives the received data using BASE64. Performs decoding processing and the like. That is, the control circuit 36 has the functions of the encryption generation unit 120, the decryption unit 220, the encoder unit, and the decoder unit of the cellular phone devices 100 and 200 shown in FIG.
The ROM 38 stores a system program for controlling the entire mobile phone device. The RAM 40 is composed of a non-volatile memory or the like, and stores predetermined information necessary for control of the control circuit 36, phone book data used for outgoing calls or transmission of e-mails, and image data such as photographs. Further, in the present embodiment, a data table for storing a mail address of a specific sender and a telephone number in association with each other is provided.

  The display 42 is a display that displays predetermined information such as the current time, telephone number, and e-mail content. For example, a color LCD, EL (electroluminescence), PDP (plasma display panel), or the like. It consists of The illumination unit 46 illuminates the display 42 and keys. The input unit 44 includes a numeric keypad 48 for inputting a telephone number and the like, a call key 50 for operating the start of a call, a cut key 52 for operating the end of the call, and a function key 54 for setting various functions. Have.

  Next, the processing operation of the cellular phone device (transmission side) according to the present embodiment will be described based on the flowchart shown in FIG.

  First, the mobile phone device on the transmission side temporarily stores the mail text input by the input unit 44 in the RAM 40 in step S1.

  If the control circuit 36 determines in step S2 that there is a mail transmission instruction from the input unit 44, the process proceeds to step S4.

  In step S3, the control circuit 36 determines whether or not the same address as the transmission destination address of the mail instructed in step S2 is stored in the RAM 40. If it is stored, the process proceeds to step S4. Otherwise, the process proceeds to step S6.

  In step S4, the control circuit 36 reads out the telephone number corresponding to the mail transmission destination address from the RAM 40, and also reads out the telephone number of the mobile phone device 100 itself, and reads the mail text data stored in the RAM 40 character by character. Then, the last four digits of the sender telephone number and the last four digits of the receiver phone number are alternately ORed to generate binary data of the encrypted mail text.

  In step S5, the control circuit 36 performs character conversion on the binary data generated in step S4 based on BASE64. The base 64 here is binary data, that is, a byte string is divided into 3 bytes (24 bits), and the 24 bits are further divided into four groups of 6 bits, each of which is a total of 64 from 0 to 63. It is expressed as a number of types. More specifically, the 6 bits of the original binary data are regarded as numbers from 0 to 63, and these are the uppercase letters, lowercase letters (total of 26 characters x 2 52 characters), numbers, respectively. 0 to 9 (10 characters in total) and 64 characters of “+” and “/” are encoded to encode data. When the number of bytes of binary data to be transmitted is not a multiple of 3, one or two “=” is added to the result (padding processing) so that the number of characters of the encoding result is a multiple of 4. The data converted (encoded) by the BASE 64 is wirelessly transmitted to the other party by the communication unit 12 in step S6.

  Next, the operation on the receiving side will be described.

In step S21, when the control circuit 36 determines that the mail has been received, the process proceeds to step S22.
In step S22, the control circuit 36 determines whether or not the telephone number corresponding to the sender address of the mail received in step S21 is stored in the RAM 40. If it is stored, the process proceeds to step S23. Otherwise, the process proceeds to step S25.

  In step S23, the control circuit 36 performs character conversion (decoding) by BASE64.

  In step S24, the control circuit 36 encrypts the binary data decoded in step S23 by taking an exclusive OR with the telephone number on the transmission side and the telephone number on the reception side in the same manner as in step S4 on the transmission side. Decipher the data.

  In step S25, the control circuit 36 stores the decrypted data in the RAM 40. Note that the data that has been encrypted in step S23 but for which the telephone number data is not stored in the RAM 40 is stored as it is encrypted, and the data that is not encrypted on the transmission side is stored in the RAM 40 as it is.

  The data stored in the RAM 40 in this way can be displayed on the display 42 according to the user's instruction operation.

  In this way, the device of this embodiment encrypts the mail text to be transmitted based on the telephone number on the transmitting side and the telephone number on the receiving side, so that when the third party intercepts the data of the transmitted mail text However, since it is difficult to decipher the encryption, it is possible to protect the secret of the information when transmitting important data.

In this embodiment, the mail text is encrypted, but the mail address, mail title, etc. may be encrypted.
As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and includes design changes and the like within a scope not departing from the gist of the present invention. It is.
In this embodiment, encryption is performed based on the telephone number on the transmission side and the telephone number on the reception side. However, encryption may be performed based on only the telephone number on either the transmission side or the reception side.

It is a system configuration | structure figure of a present Example apparatus. It is a block diagram of the mobile telephone apparatus of a present Example apparatus. It is a process flowchart of the mobile telephone apparatus of a present Example. It is a process flowchart of the mobile telephone apparatus of a present Example.

Explanation of symbols

12 Communication Unit 16 Antenna 36 Control Circuit 40 RAM
42 Display 44 Input section

Claims (4)

Means for storing destination information at the time of transmission and mail information having a mail body;
Collation means for collating the destination information included in the stored mail information with preset destination information;
An encryption key generating means for generating an encryption key when the destination information included in the mail information matches the preset destination information;
Encryption means for encrypting the mail text stored in the storage means based on the generated encryption key;
Sending means for sending the mail body encrypted by the encryption means;
A mobile phone device comprising: A data table that stores email addresses and telephone numbers in association with each other is provided.
The encryption key generation unit generates an encryption key from a telephone number of a sender and a telephone number of a receiver when a mail address included in the mail information to be transmitted exists in the data table. Item 2. The mobile phone device according to Item 1.   3. The mobile phone device according to claim 1, further comprising decryption means for decrypting the encrypted mail text using the encryption key. A sending terminal that encrypts and transmits character data with the sending phone number and the receiving phone number;
A receiving terminal that decrypts the encrypted character data received from the transmitting terminal with a transmitting telephone number and a receiving telephone number;
A communication system having at least

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