JPS61264936A - Formation system for transferring table - Google Patents

Abstract

PURPOSE:To form quickly a transferring table by obtaining a remainder from a random data outputted from a block ciphering device receiving an input data string while using the idle number of digit of a transferring table as a divisor and applying arrangement conversion to the data string based on the obtained remainder and outputting the result with the conversion of a string. CONSTITUTION:A modulo calculation section 10 uses an idle digit number (n) of a transposition table to apply division to a random number (x) generated by a block ciphering device 5 so as to obtain a remainder (y), which is sent to an ordinal number arranging section 11, which sets the next ordinal number 5 to the idle digit of the digit of remainder y=0 sent from the modulo calculation section 10 from the next idle digit storing ordinal numbers 4 of the transposition table. Since the modulo calculation section 10 and the ordinal number arranging section 11 divide random numbers (x) generated by 5 times by the block ciphering device 5 to complete the transposition table in 5 digits, it is not required to provided the transferring table section 4 storing lots of transposition tables and the time to complete the transposition table is ensured. Thus, the transferring table is formed economically and quickly.

Description

[Detailed Description of the Invention] [Summary] In a cryptographic communication system that transposes a data string and sends it to a communication line, a random number output from a block cipher is divided by the number of empty digits in a transposition table to obtain a remainder; By arranging the ordinal numbers based on the obtained remainder, a transposition table indicating the transposition rule can be obtained economically and quickly.

[Industrial application field]

The present invention relates to a method of encrypting and transmitting a data string by transposition, and assuming that the data string is, for example, a voice spectrum,
This paper relates to a method for creating a transposition table in a communication system that encrypts audio by transposing the frequency spectrum.

One method of encrypting and transmitting audio signals is to transpose the frequency spectrum array (data string) of the audio signal on the transmitting side based on a predetermined protocol, and transmit the resulting encrypted audio signal to the receiving side via a communication line. An encrypted communication system has been put into practical use in which the received encrypted audio signal is reversely transposed on the receiving side to restore the original audio signal based on the same rules as the transmitting side.

In this type of encrypted communication system, it is necessary to set a predetermined rule (hereinafter referred to as a transposition table) that serves as a standard for the transposition of the audio spectrum (data string) and the inverse transposition of the encrypted audio signal, and the transposition table It is desired to realize an economical and quick means for producing.

[Conventional technology]

FIG. 4 is a diagram showing an example of a conventional transposition table creation method.

In FIG. 4, an analog audio signal to be encrypted and transmitted is converted into a digital audio signal by an analog-to-digital converter (A/D) 1, and then converted into a digital audio signal by a fast Fourier transformer (FFT) 2 in predetermined cycle units. The signal is converted from the domain to the frequency domain and transmitted to the transposing unit 3.

On the other hand, the transposition table section 4 stores a plurality of transposition tables for transposing the frequency spectrum to which the transposition section 3 is input. Supplied.

The transposition unit 3 transposes the audio spectrum transmitted from the fast Fourier transform unit 2 based on a device table constituted by the transposition table unit 4, and then transposes the audio spectrum transmitted from the fast Fourier transform unit 2 to an inverse fast Fourier transform unit (F
FT”)6.

The inverse fast Fourier transform unit 6 converts the audio spectrum obtained by the transposing unit 3 from the frequency domain to the time domain in predetermined period units, converting the digitally encrypted audio signal into a digital-to-analog converter ( D/A) 7.

The digital-to-analog converter 7 converts the digital encrypted audio signal transmitted from the inverse fast Fourier transformer 6 into an analog encrypted audio signal, and then sends the signal to the communication line 8 .

Next, FIG. 5 is a diagram showing another example of a conventional transposition table creation method. Note that the same reference numerals refer to the same objects throughout the plan.

In FIG. 5, an analog-to-digital converter 1, a fast Fourier transformer 2, a transpose unit 3, an inverse fast Fourier transformer 6, and a digital-to-analog converter 7 convert the target analog audio into The signal is encrypted and sent to the communication line 8.

In FIG. 5, a block cipher 5 and a duplicate random number removing section 9 are provided to create a transposition table to be supplied to the transposition section 3. The duplicate random number removing unit 9 removes duplicate random numbers from the random numbers generated by the block encoder 5, arranges random numbers suitable for the transposition table, creates a transposition table, and supplies the table to the transposition unit 3.

[Problem that the invention seeks to solve]

As is clear from the above explanation, in the conventional transposition table creation method, it is necessary to provide a transposition table unit 4 for storing a large number of transposition tables as shown in FIG. 4, which may impair the economic efficiency of the cryptographic communication system. As shown in FIG.
Since the transposition table is created from random numbers generated by , the supply time of the transposition table becomes uncertain, and there is a possibility that the transposition table may not be supplied at each predetermined period.

[Means for solving problems]

FIG. 1 is an explanatory diagram of the principle of the present invention. Encryption is performed by converting random data (random numbers) output from a block cipher 5 into a transposition table for input data strings A, B, CSD, and H. Method a for calculating the remainder using the number of empty digits as the divisor (
In FIG. 2, the remainder obtained by 10) is used.

Data strings A, B, C, D based on the obtained remainder.

E is array-transformed (transposed) by array means b (11 in FIG. 2) and output as data sequences C, E, A, B.

[Effect]

That is, according to the present invention, the required transposition table is created by dividing the number of digits in the transposition table, so there is no need to provide a transposition table section 4 (FIG. 4) that stores a large number of transposition tables in advance. , the time for creating the transposition table is also determined, and the transposition table is quickly created.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram showing a transposition table creation method according to an embodiment of the present invention, and FIG. 3 is a diagram showing an example of the process of creating the transposition table in FIG. 2.

Note that the same reference numerals refer to the same objects throughout the plan.

In FIG. 2, a modulo calculating section 10 is provided as a means for calculating the remainder, and an ordinal number arranging section 11 is provided as a means for arranging the ordinal numbers.

Also in FIG. 2, an analog-to-digital converter 1, a fast Fourier transformer 2, a transpose unit 3, and an inverse fast Fourier transformer 6 are shown.
The digital-to-analog converter 7 encrypts the target analog audio signal using the same process as shown in FIG. 3, and sends it to the communication line 8.

The modulo calculation unit 10 divides the random number X generated by the block encoder 5 by the number n of empty digits in the transposition table to obtain a remainder y (=xmod n), and transmits it to the ordinal number arrangement unit 11.

The ordinal number arrangement unit 11 sets the ordinal numbers (1, 2, . . . , n) to the second order based on the remainder y transmitted from the modulo calculation unit 10.
They are arranged by the process illustrated in the figure.

In FIG. 2, the number of empty digits in the transposition table is n-5, and the generated random numbers are assumed to be 3.8.7.5.4 in the following explanation.

The block cipher 5 first generates a random number x=3 and transmits it to the modulo calculation unit 10.

The modulo calculation unit 10 divides the random number x=3 by the number of empty digits n=5 in the transposition table to obtain a remainder y=3, and transmits the remainder to the ordinal number arrangement unit 11.

The ordinal number arrangement unit 11 sets the first ordinal number 1 to the empty digit (third digit) of the remainder y = third digit transmitted from the modulo calculation unit 10 from the head (0th digit) of the transposition table.

As a result of the above, the number n of empty digits in the transposition table is 4.

Next, the block cipher 5 generates a random number x=8 and transmits it to the modulo calculation unit IO.

The modulo calculation unit 10 divides the random number x=8 by the number of empty digits n=4 in the transposition table to obtain a remainder y−0, and transmits the remainder to the ordinal number arrangement unit 11.

The ordinal number array unit 11 selects the remainder y=o-th empty digit (fourth digit) transmitted from the modulo calculation unit 10 from the next empty digit (fourth digit) where the ordinal number 1 of the transposition table is stored. Set the next ordinal number 2 to .

As a result of the above, the number n of empty digits in the transposition table becomes three.

Next, the block cipher 5 generates a random number x=7 and transmits it to the modulo calculation unit 10.

The modulo calculation unit 10 divides the random number x=7 by the number of empty digits n=3 in the transposition table to obtain a remainder y=x, and transmits the remainder to the ordinal number arrangement unit 11.

The ordinal number array unit 11 calculates the remainder y = 1st empty digit (1st digit) transmitted from the modulo calculation unit IO from the next empty digit (0th digit) where the ordinal number 2 of the transposition table is stored. Set the next ordinal number 3 to .

As a result of the above, the number n of empty digits in the transposition table becomes 2.

Next, the block cipher 5 generates a random number x=5 and transmits it to the modulo calculation unit 10.

The modulo calculation unit 10 divides the random number x=5 by the number of empty digits n=2 in the transposition table to obtain a remainder y=t, and transmits the remainder to the ordinal number arrangement unit 11.

The ordinal number array unit 11 calculates the remainder y = the first empty digit (0th digit) transmitted from the modulo calculation unit 10 from the next empty digit (second digit) in which ordinal number 3 of the transposition table is stored. Set the next ordinal number 4 to .

As a result of the above, the number n of empty digits in the transposition table becomes l.

Next, the block cipher 5 generates a random number x=4 and transmits it to the modulo calculation unit 10.

The modulo calculation unit 10 divides the random number x=4 by the number of empty digits n=l in the transposition table to obtain a remainder y=o, and transmits the remainder to the ordinal number arrangement unit 11.

The ordinal number array unit 11 calculates the remainder y = 0th empty digit (second digit) transmitted from the modulo calculation unit 10 from the next empty digit (second digit) in which the ordinal number 4 of the transposition table is stored. Set the next ordinal number 5 to .

With the above steps, the transposition table is completed.

As is clear from the above description, according to the present embodiment, the modulo calculating section 10 and the ordinal number arranging section 11 divide the random number X generated five times by the block cipher 5.
To complete the digit transposition table, a large number of transposition tables (
Transposition table section 4 that stores 120 types (in the case of 5 digits)
(FIG. 4) is not necessary, and the time required to complete the transposition table is also fixed.

Note that FIGS. 2 and 3 are only one embodiment of the present invention, and for example, the random number X generated by the block cipher 5 and the number of digits in the transposition table are not limited to those shown in the figures. Although many other modifications may be considered, the effects of the present invention remain the same in any case. It goes without saying that the configuration of the cryptographic communication system to which the present invention is applied is not limited to that shown in the drawings.

〔Effect of the invention〕

As described above, according to the present invention, in the encrypted communication system, the required transposition table is created by dividing the number of digits of the transposition table, so it is not necessary to provide a transposition table section that stores a large number of transposition tables in advance. Moreover, the time required to create the transposition table is fixed, and the transposition table can be produced economically and quickly.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a diagram showing a transposition table creation method according to an embodiment of the present invention, and FIG.
FIG. 4 is a diagram showing an example of the process of creating a transposition table in the figure; FIG. 4 is a diagram showing an example of a conventional transposition table creation method;
FIG. 5 is a diagram showing another example of a conventional transposition table creation method. In the figure, ■ is the analog-to-digital converter (A/D)
, 2 is a fast Fourier transform unit (FFT), 3 is a transposition unit,
4 is a transposition table section, 5 is a block cipher, 6 is an inverse fast Fourier transform section (FFT-''), 7 is a digital-to-analog conversion section (D/A), 9 is a duplicate random number removal section, 10 is a modulo calculation section, 11 is the ordinal number array part, n is the number of empty digits in the transposition table, X is the random number, and y is the remainder. f riddle l and σ゛] o, 46n
Gi 3 Roy L Notsumi'j h large 7f h? ] Rod 4 A maple showing a circle of 0 and a 30-year-old tree 5 Kuni

Claims (1)

[Scope of Claims] In a cryptographic communication system in which a data string is transposed based on a transposition table and sent to a communication line, means (a ); and means (b) for arranging ordinal numbers based on the remainder output by the means (a).