KR100336199B1 - Facsimile apparatus - Google Patents

Abstract

It is an object of the present invention to provide a facsimile device that reduces the device load by simplifying the multiplication procedure that takes 64 bits in length by using a 32-bit hash function.

Here, the obtained mail address is supplied to the hash function as an argument. The hash function uses the same function used on the receiving side. At this time, the output size of the hash function is selected to be 32 bits long. The name uniquely designating the user by the hash function is rounded to 32 bits and uses the decimal notation as the sub-address. The sender user inputs the mail address instead of the sub address. The hash function is calculated using two 32-bit hash functions rather than 64-bit long. In other words, divide the 20-digit sub-address into two regions of 10 digits and use a 32-bit hash function for each.

Description

Facsimile device {FACSIMILE APPARATUS}

The present invention relates to a facsimile device that calculates and transmits a sub address using a hash function when transmitting and receiving data with another device through a network.

Recently, a network-compatible facsimile apparatus capable of connecting with other terminal apparatuses via a network and transmitting / receiving data with those apparatuses has become popular. In this network-adaptive facsimile apparatus, the receiving side apparatus on the network is uniquely identified according to the identification information attached to the facsimile message received from the transmitting side apparatus over the line, and the specific number is determined using a local area network (LAN) interface. The received facsimile data for the message is transmitted over the network.

Specifically, the sending side apparatus specifies the fax number of the receiving side apparatus as the destination fax number, and furthermore, designates and calls an identification number for specifying to a desired recipient (specific individual) on the network as a sub-address and calls the receiving side. A fax message has been sent to the device.

On the other hand, the receiving apparatus assigns a mailbox ID to each individual user in advance, acquires a numeric string obtained from the received sub-address added to the received fax message as the mailbox ID, and specified by this mailbox ID. The received fax message to a sent mailbox. Therefore, in order to correctly specify the destination, the user of the sending side apparatus is required to reliably recognize the correspondence between each individual of the receiving side apparatus and the mailbox ID.

However, since the correspondence between the individual and the mailbox ID is unique for each receiving side facsimile apparatus, there is a problem when the same person has a mailbox in a plurality of receiving side facsimile apparatuses. That is, the user of the sending side apparatus has to designate a different mailbox ID as a sub-address for each receiving side facsimile apparatus, even if he wants to transmit to a specific individual. In addition, the user side of the transmitting side apparatus had to recognize many mailbox IDs for the same receiving side.

In order to solve such a problem, in the invention described in Japanese Patent Laid-Open No. 10-257290, the name of a destination name string corresponding to each destination on a network is uniquely accepted as sub-address information by using a hash function. Converts a symbol string obtained as sub-address information to be converted into a destination symbol string, stored in correspondence with the respective destination symbol strings, and added to a facsimile message received from the transmitting apparatus via a line; A destination message is identified by matching destination symbol strings in contrast to each stored destination symbol string, and the received fax message is transmitted to the specified destination. Therefore, a unique destination symbol string is given to a destination name string corresponding to the same destination, so that the destination designation operation can be facilitated in facsimile communication that specifies the destination, and destination management Reduce the burden

However, in the invention described in Japanese Patent No. 10-257290, a value obtained by inputting a magnetic name or a mail address and calculating it by a hash function is used as a sub address. .

In addition, it is impossible in principle to prevent collisions of hash values, and the smaller the bit length, the higher the probability of collision.

Furthermore, from the one-way characteristic of the hash function, calculation of the mail address from the hash value was impossible. Therefore, in the above technique, a sub-address mail address correspondence table is prepared to calculate a mail address, but it is very inconvenient to manage the mail address of a remote place on the Internet.

Accordingly, a first object of the present invention is to provide a facsimile device that uses a 32-bit long hash function to simplify the multiplication procedure of a 64-bit long hash function, thereby reducing the load on the device.

It is also a second object of the present invention to provide a facsimile apparatus that reduces the possibility of collision of hash values even when using a hash function having a small number of bits.

Furthermore, it is a third object of the present invention to provide a facsimile apparatus that calculates a mail address from a hash value.

1 is a diagram showing a basic hardware configuration of a facsimile according to the present embodiment.

2 illustrates a facsimile protocol.

3A to 3C are diagrams illustrating a sub address frame SUB.

<Description of Symbols for Major Parts of Drawings>

1001: CPU (Central Processing Unit)

1002: ROM (Read Only Memory)

1003: system memory (RAM)

1004: Timer

1011: Image storage memory

1021: LAN Controller

1031: modem

1041 encoder / decoder (DCR)

1051: Scanner

1052: Printer

In the invention described in claim 1, the network is connected to another terminal device via a network, and the facsimile message received from the transmitting device via a line is specified by a symbol string received as sub-address information added to the facsimile message. A fax device for transmitting to a destination, comprising: converting a destination name string corresponding to each destination on the network into a unique destination symbol string allowed as the sub-address information by hash conversion, and converting the destination address. Destination specifying information storage means for storing the symbol string in correspondence with each destination, and a symbol string obtained as sub address information received in addition to the facsimile message received from the transmitting apparatus, in the destination specifying information storage means. Matches against each destination symbol string matched Destination specifying means for specifying a destination by means of a symbol code string, and transmission means for transmitting the received facsimile message to a destination specified by the destination specifying means, and having a 32-bit length in performing the hash conversion. The first object is achieved by calculating using the hash function twice.

In the invention as set forth in claim 2, in the hash conversion, the second object is achieved by making one of the areas in which the sub-address is divided into two as the Internet protocol address of the partner mail server.

In the invention as set forth in claim 3, according to claim 1, the third server is provided with a Simple Mail Transfer Protocol (SMTP) server function and simultaneously registers a hash value calculated from a mail account as an alias when the mail account is added. Achieve the purpose.

Example

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3 (a) to (c).

1 is a diagram showing the basic hardware configuration of the facsimile according to the present embodiment. The facsimile apparatus 100 includes a CPU (central processing unit) 1001, a ROM (read only memory) 1002, a timer 1004, an image storage memory 1011, a LAN controller 1021, a modem (MODEM) 1031, A coding / decoding machine (DCR) 1041, a scanner 1051, a printer 1052, and a system memory (RAM) 1003 are provided. A transformer 1022 is connected to the LAN controller 1021 and a detector (NCU = line control unit) 1032 is connected to the modem 1031.

The system memory (RAM) 1003 temporarily stores data necessary for the control of the facsimile. The ROM 1002 stores the control procedure of the facsimile, and the scanner 1051 uses the facsimile transmission operation. The modem 1031 realizes modulation for enabling binary coded image information to be transmitted over the public line and demodulation for returning the code of the image information modulated from the other side to the original binary code. The detector (NCU) 1032 detects and analyzes the DTMF (Double Tone Multi-Frequency) signal on the other side. The encoder / decoder 1041 compresses and encodes the binary image read by the scanner, and decodes the binary image so that the compressed code sent by the counterpart can be printed. The printer 1052 records image information decoded by the decoder 1041 on paper and outputs it.

The LAN controller 1021 and the transformer 1022 control the Ethernet network, control the PSTN (public switched telephone network) with the modem 1031 and the detector 1032, and communicate via the PSTN. Is encoded and decoded by the encoder / decoder 1041.

The received fax image is stored in the image storage memory 1011 via the detector 1032 and the modem 1031. The image storage memory 1011 can also be used as the RAM 1003. An e-mail address is determined based on sub-address information and TSI (Transmitting Subscriber Identification) information obtained at the same time when receiving a fax, and the accumulated e-mail address is determined. The fax image and the incoming notification mail are transmitted to the respective client hosts on the Ethernet via the LAN controller 1021, the transformer 1022, and the like.

The recipient enters his or her name or mail address when creating a mailbox and associates the value obtained by calculating it with a hash function as a sub address, and the sender uses the name or mail of the other user used when creating the mailbox at the time of designating the mailbox. The hash function value obtained by inputting the address is transmitted as the sub address. The sub address mail address correspondence table 1013 is not necessary.

2 is a diagram illustrating a fax protocol. The basic facsimile can communicate with the other party and receive an image from the other party by the protocol shown in FIG. First, when the transmitting side TX is connected to the receiving side RX, it transmits a Calling Tone (CNG) signal to declare itself as a facsimile terminal.

On the other hand, when the receiving side (RX) connects the line, it sends a Called Station Identification (CED) to declare that it is a facsimile and a receiving state.

Then, NSF (Non-Standard Function) and DIS (Standard Function) are sent to inform the transmitting side of the function it has. From the contents of the received NSF and DIS, the transmitting side determines the function to be used for transmission, and sends an NSS (non-standard function) or DCS (standard function) to inform the receiving side. In some cases, the SUB (sub address) is also transmitted in front of the DCS. Thereafter, TCF (training) is performed at the modem speed used for the transmission of the image information from the determined function.

If the training succeeds, the receiver returns the CFR (Receive Confirmation Signal) to enter the reception state of the image information. Upon receiving the CFR, the transmitting side transmits the image information at the modem speed used in the training, and issues an EOP (end of procedure) to notify the receiving side of the end of the image information when the transmission of the image information is finished. The receiving end sends an MCF (message confirmation signal) when the image information can be received normally. The circuit is disconnected in accordance with the transmission of the DCN (disconnection command).

In this embodiment, in this part, the SUB (sub address) or the like before DIS is used as transmission information. Normally, a sub-address is designated for a mailbox ID and transmitted to the mailbox. In addition, the incoming notification mail or the like at the time of transmission can determine to which mail address to send the received fax image or incoming notification mail by preparing a correspondence table between the sub address and the mail address of the destination user.

The basic operation of facsimile transmission has been described above, but the problem here is the format of the sub-address. Only 20 digits (and a few symbols) can be assigned to a SUB frame. Therefore, when this is used for delivery of a mailbox, a number of up to 20 digits is calculated using a hash function as in the invention described in JP-A-10-257290, but the calculation load is high. In this embodiment, the following subaddress problem is solved by the following method.

Also, the hash function is described here. The hash function converts the data (key value) given as an argument into a unique value which is not duplicated according to a predetermined conversion algorithm. The hash function mainly finds the storage address of the key value from the record key value in the information processing field. It is used to improve the retrieval efficiency of the storage address of the record key value. Different methods exist for hash functions due to differences in the conversion algorithms. In other words, the value after conversion is considered to be equally distributed so as not to overlap as much as possible after the conversion. In this hash function, the larger the number of digits allowed as the value after the conversion, the less the possibility of duplicate values after the conversion.

Therefore, the value obtained by converting the character string (value composed of the character code string of) as the user name during the mailbox ID assignment operation as the argument of the hash function is used as the hash sub address corresponding to each mailbox ID. The mail address IDs are assigned unique values (symbol strings) that do not overlap each other.

Next, the processing of the first embodiment will be described.

The sender first sends a fax to the recipient user, at which time the recipient's mail address is specified.

In this embodiment, the obtained mail address is given to the hash function as an argument. The hash function uses the same function used on the receiving side. At this time, the output size of the hash function is selected to be 32 bits long. The name uniquely designating the user by the hash function is rounded to 32 bits, and the decimal notation is used as the sub address. The sender user inputs the mail address instead of the sub address.

When calculating the hash function, the 32-bit hash function is calculated twice without using the 64-bit hash function. In other words, divide the 20-digit sub-address into two regions of 10 digits and use a 32-bit hash function for each. In other words, the mail address is divided into two in the appropriate parts and given two hash functions, respectively. In this way, two hash values are obtained.

3A to 3C are diagrams for explaining the sub address frame SUB. Fig. 3A shows a conventional 64-bit length, and Fig. 3B shows a 32-bit length according to the present example.

32-bit lengths can be represented in decimal notation, from 0 to 4294697295. That is, since the output result is less than 10 digits, two 32-bit hash function outputs are connected to generate a 20 digit number, which is a sub address.

It is also possible to use two kinds of hash functions as another method of this embodiment. In addition, it is also possible to add and use different parameters when giving a mail address to two hash functions.

Next, a second embodiment will be described. In this embodiment, the following are necessary in addition to the operation of the first embodiment.

As a component, you will need a Domain Name System (DNS) server on your network. However, DNS exists as long as there is an environment for accessing the Internet.

First, mail addresses are divided into @ front part (account) and @ back part (domain). The account portion is converted to a 32-bit length, that is, 10 decimal digits using a hash function as in the first embodiment.

As for the domain part, the IP (Internet Protocol) address of the mail address mail server is obtained using DNS. This order is predetermined by the RFC.

This IP address is an address for identifying a node on the network. The IP address is a number that can be expressed as a 32-bit value and is assigned to each node on the network. By using this IP address, the communication partner can be specified.

An IP address is represented by four sets of numbers, which are four bytes long (32 bits) of data. Thus, this IP address can be represented by 10 decimal digits.

Then, the decimal representation portion of the hash value obtained from the account portion and the decimal representation portion of the value selected from the IP address are concatenated to generate 20 digits, which are used as sub-addresses.

In addition, in this embodiment, the sub address frame SUB is shown in Fig. 3C.

Next, a third embodiment will be described. In addition to the operation of the second embodiment, the following is required.

In the receiving mail server, when a new account is created, 10 decimal digits obtained from the output of the hash function used in the second embodiment are also registered as the alias.

The received fax communicates with the server by SMTP since the IP address of the mail server can be known from the format of the sub-address of the second embodiment. SMTP order is specified by RFC822 and others.

When the server and the SMTP sequence are established, if the hash value is designated as the mail account, the receiving mail server transmits to the correct account because the alias is already set on the receiving mail server.

According to the invention described in claim 1, the multiplication procedure for the 64-bit long hash function is simplified by using the 32-bit long hash function, and as a result, the computational load is reduced.

According to the invention described in claim 2, since the IP address is guaranteed to be a unique number uniquely in the Internet world, there is no possibility that a collision occurs in an area using the IP address as part of the sub address.

According to the invention described in claim 3, the mail sent via the Internet is recognized as an alias even if the account name portion of the mail address is a hash value.

Claims (3)

A facsimile device that is connected to another terminal device by a network and transmits a facsimile message received from a sending device via a line to a destination on the network specified by a symbol string received as sub-address information appended to the facsimile message. In Converts a destination name string corresponding to each destination on the network into a unique destination symbol string allowed as the sub-address information by hash conversion, and converts the converted destination symbol strings into respective destinations, respectively. Destination specifying information storage means for storing in correspondence; A destination string is identified by matching destination symbol strings by matching the symbol strings obtained as sub-address information received in addition to the facsimile message received from the transmitting side device with the destination symbol strings stored in the destination specifying information storage means. Destination-specific means, Transmitting means for transmitting the received fax message to a destination specified by the destination specifying means, The facsimile device, characterized in that for calculating the hash, using a 32-bit hash function twice. 2. The facsimile apparatus according to claim 1, wherein at the time of the hash conversion, one of the areas in which the sub-address is divided into two is used as the Internet protocol address of the partner mail server. 2. The facsimile apparatus according to claim 1, wherein the facsimile apparatus includes an SMTP server function and simultaneously registers a hash value calculated from the mail account as its alias.