JP2004226852A - Pseudo random number generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further prevent leakage of information to a third party. <P>SOLUTION: A pseudo random number D1 is generated by using a result derived on the basis of prescribed information used in a prescribed communication protocol as seeds, and a partial random number D3 or a hash value D4 is generated by changing the state of a random number sequence in the pseudo random number D1 by providing the pseudo random number D1 with a signal processing to reduce the information amount of the pseudo random number D1. Consequently, even when the partial random number D3 (or the hash value D4) is illegally obtained during transmission, it is possible to prevent the third party from guessing the pseudo random number D1 which is the generating source of the same without allowing the third party to find the pseudo random number D1 on the basis of the partial random number D3 (or the hash value D4). In this way, leakage of information to the third party can be further prevented. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pseudorandom number generation device, a pseudorandom number generation method, and a transmission device, and is suitably applied to, for example, a pseudorandom number generation device provided in a transmission device that transmits information via the Internet.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a pseudo-random number generation device generally generates pseudo-random numbers sequentially using pseudo-random numbers output according to, for example, a linear congruential generation method (Linear Conjunctive Generators) again as an input.
[0003]
In addition, the pseudorandom number generation device increases a run rate during generation of the pseudorandom number by using a MASK value that can selectably determine a polynomial used when generating the pseudorandom number. There is a technique for improving the randomness of a column in a pseudo-random number being generated (for example, Patent Document 1).
[0004]
[Patent Document 1]
JP-A-6-103035
[0005]
[Problems to be solved by the invention]
By the way, in the pseudorandom number generation device, although the degree of randomness of the column in the pseudorandom number is improved, the next pseudorandom number is generated by using the output result of the pseudorandom number as an input, so that the pseudorandom number at a predetermined time is When it is obtained by a third party, it is easy to guess the method of generating the pseudo random number based on the pseudo random number, and there is a problem that leakage of information to the third party is relatively large.
[0006]
The present invention has been made in view of the above points, and it is an object of the present invention to propose a transmission device and a transmission method that can further prevent information leakage to a third party.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, in the present invention, a pseudorandom number is generated using a derivation result derived based on information used in a predetermined communication protocol as a seed, and a predetermined signal processing is performed on the generated pseudorandom number. To generate random number sequence change information in which the state of the random number sequence in the pseudo random number is changed.
[0008]
In this case, even if the random number sequence change information is obtained by a third party, the random number sequence change information changes the state of the random number sequence in the pseudo random number. Based on the column change information, it is possible to prevent the guess of the pseudo-random number that is the source of the change.
[0009]
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0010]
(1) Overall configuration
In FIG. 1, reference numeral 1 denotes a transmission / reception system to which the present invention is applied as a whole. A transmission device 2, a reception device 3, and a communication obstruction device 4 are connected to the Internet 5, and the transmission device 2 and the reception device 3 are connected to the Internet. 5, various data can be exchanged.
[0011]
The transmission device 2 divides the transmission target data into data pieces of a predetermined length, performs packet encryption processing on the data pieces according to a predetermined communication protocol, and sequentially generates transmission packets PK (PK1, PK2, ...) To the receiving device 3.
[0012]
The reception device 3 receives the transmission packet PK transmitted from the transmission device 2, performs a packet decoding process on the transmission packet PK according to the same communication protocol as that of the transmission device 2, and outputs a data fragment restored as a result. For example, it is stored in an internal memory (not shown).
[0013]
The communication interfering device 4 performs a Denial of Service (DoS) action on the receiving device 3, and more specifically, a transmission packet PK (PK1) transmitted from the transmitting device 2 to the receiving device 3. , PK2,...), Illegally obtains the transmission packet PK (PK1, PK2,..., Or PKn) during the transmission, and modifies the content of the obtained transmission packet PK (hereinafter, referred to as a transmission packet PK). This is called a content change packet), and the FPK is generated, copied in large quantities, and then transmitted to the receiving device 3 sequentially.
[0014]
Here, upon receiving a large amount of the content change packet FPK transmitted from the communication interfering device 4, the receiving device 3 requests data DNa for requesting the start of a countermeasure against a denial of service (hereinafter referred to as a denial of service countermeasure). Is generated and transmitted to the transmission device 2.
[0015]
In this case, the transmitting device 2 adds identification information for identifying only the receiving device 3 to the transmitting packet PK sequentially generated after receiving the request data DNa transmitted from the receiving device 3 as a service denial measure. , And sequentially transmits transmission packets (hereinafter referred to as anti-jamming packets) BMPK (BMPK1, BMPK2,...) To the reception device 3.
[0016]
Even if the interference countermeasure packet BMPK is illegally obtained by the communication jammer 4 when transmitted from the transmitter 2 to the receiver 3, the generation pattern of the identification information added to the jammer packet BMPK is obtained. Has not been deciphered.
[0017]
The receiving device 3 receives the anti-jamming packet based on the identification information added to the anti-jamming packet BMPK among the anti-jamming packet BMPK transmitted from the transmitting device 2 and the content change packet FPK transmitted from the communication interfering device 4. Only the BMPK can be restored and the resulting data fragment can be stored in an internal memory (not shown).
[0018]
Further, when the number of content change packets FPK transmitted from the communication interfering device 4 decreases, the receiving device 3 generates request data DNb requesting stop of the service denial countermeasure, and transmits this to the transmitting device 2.
[0019]
In this case, the transmission device 2 transmits the transmission packet PK sequentially generated after receiving the request data DNb transmitted from the reception device 3 to the reception device 3 without adding identification information.
[0020]
As described above, the transmission / reception system 1 receives the content change packet FPK in the receiving device 3 while transmitting and receiving a plurality of transmission packets PK between the legitimate transmitting device 2 and the receiving device 3 via the Internet 5 at that time. Depending on the situation, the transmission device 2 is requested to determine whether or not identification information is added via the request data DN (DNa, DNb). The anti-jamming packet BMPK to which the identification information that the generated pattern cannot be deciphered is added by the device 4 can be transmitted and received between the transmitting device 2 and the receiving device 3.
[0021]
(2) Configuration of transmitting device
As shown in FIG. 2, the transmission device 2 includes a message processing unit 11, a packet generation unit 12, and a communication unit 13, and is configured to input request data DN via the Internet 5 and the communication unit 13 sequentially. ing.
[0022]
The message processing unit 11 performs a period from when the request data DNa requesting the start of the service denial countermeasure is provided to when the request data DNb requesting the stop of the service denial countermeasure is provided (hereinafter referred to as a service denial countermeasure period). Call) are executed.
[0023]
Therefore, the message processing unit 11 can reduce its own processing load and power consumption, and as a result, can also reduce the processing load and power consumption of the entire transmission device 2.
[0024]
Upon receiving the request data DNa, the pseudo-random number generation unit 20 of the message processing unit 11 uses the derivation result derived based on predetermined information such as encryption key information used in the communication protocol as a seed, and for example, according to a linear congruential generation method. Using the obtained output result as an input, pseudo-random numbers D1 (D1a, D1b,...) Of 32 bits are sequentially generated and provided to the counter unit 21 and the filter unit 22.
[0025]
The counter unit 21 increments the internal counter by “1” each time the pseudorandom number D1 is sequentially supplied from the pseudorandom number generation unit 20 and also sets a sequential number (hereinafter, referred to as a sequence number) corresponding to the incremented number of the internal counter. D2) to the message generator 23.
[0026]
As shown in FIG. 3, the filter unit 22 includes a pseudo random number input switching unit 30, a first filter unit 31, and a second filter unit 32, and outputs the pseudo random number D1 given from the pseudo random number generation unit 20. It is input to the pseudo random number input switching unit 30.
[0027]
The input pseudo-random number input switching unit 30 changes the input path of the pseudo-random number D1 provided from the pseudo-random number generation unit 20 every time a request for the request data DNa transmitted from the receiving device 3 is provided. The second filter unit 32 is switched.
[0028]
The first filter unit 31 generates a partial random number D3 that is a part of the pseudorandom number D1 by extracting the upper 16 bits of the pseudorandom number D1 composed of 32 bits provided from the pseudorandom number input switching unit 30. This is given to the message generator 23 (FIG. 2).
[0029]
Therefore, the first filter unit 31 discards the information amount of the partial random number sequence in the pseudo random number for the partial random number D3 even when the partial random number D3 is illegally obtained by a third party. It is possible to make it difficult to estimate the generation method of the linear congruential generation method in the pseudorandom number generation unit 20 based on the partial random number D3. As a result, the pseudorandom number D1 and the subsequent random number D1 corresponding to the illegally obtained partial random number D3 can be obtained. Has been made to be able to avoid generation.
[0030]
On the other hand, the filter unit 32 converts the pseudorandom number D1 given from the pseudorandom number input switching unit 30 according to a predetermined one-way hash function algorithm, thereby reducing the hash value reduced from the information amount of the random number sequence in the pseudorandom number D1. D4 is generated and given to the message generator 23 (FIG. 2).
[0031]
Accordingly, the second filter unit 32 reduces the information amount of the random number sequence in the pseudo-random number for the hash value D4 even if the hash value D4 is obtained by a third party. Based on the hash value D4, it is possible to make it difficult to guess the generation method of the linear congruential generation method in the pseudorandom number generation unit 20, and as a result, generation of the pseudorandom number D1 or later corresponding to the illegally obtained hash value D4 Has been made so that it can be avoided.
[0032]
As described above, the filter unit 22 reduces the amount of information of the pseudorandom number D1 itself, thereby making it difficult to estimate the generation method of the linear congruential generation method in the pseudorandom number generation unit 20.
[0033]
In addition to this, the first filter unit 31 of the filter unit 22 reduces the information amount of the random number sequence in the pseudo random number by a simple process such as extracting the upper 16 bits of the pseudo random number D1, thereby obtaining the first The processing load of the filter unit 31 itself can be significantly reduced as compared with the second filter unit 32.
[0034]
As shown in FIG. 4, the message generation unit 23 adds the sequence number D2 given from the counter unit 21 to the partial random number D3 (or the hash value D4) given from the filter unit 22, for example, at the beginning of the identification information D5. Is generated and given to the packet generation unit 12.
[0035]
The packet generator 12 divides transmission target data (not shown) read from the internal memory or supplied from the outside into a plurality of data pieces each having a predetermined length.
[0036]
Here, in a period other than the service denial countermeasure period, the packet generation unit 12 encrypts a data piece according to a communication protocol called IPsec (Internet Protocol Security), which is called DES-CBC (Data Encryption Standard-Cipher Block Chaining). After generating an encrypted data piece by performing the encryption process, an IPv6 header is added, and the transmission packet PK generated as a result is transmitted to the receiving device 3 (FIG. 1) via the communication unit 13.
[0037]
On the other hand, in the case of the service interruption countermeasure period, as shown in FIG. 5, the packet generation unit 12 performs an encryption process on the data fragment to generate an encrypted data fragment, and then provides the encrypted data fragment from the message processing unit 11. The identification information D5 is added as an end point option header in an uncoded state, an IPv6 header is further added, and the resulting anti-jamming packet BMPK is transmitted to the receiver 3 via the communication unit 13.
[0038]
Incidentally, in addition to the identification information D5, an extension header length indicating the data length of the end point option header, an option data length indicating the data length of the identification information D5, and the like are added to the end point option header.
[0039]
As described above, the transmission device 2 does not know the correspondence of the combination of the partial random number D3 (or the hash value D4) and the sequence number D2 only in the service interruption countermeasure period, and The combination is such that the anti-jamming packet BMPK to which the identification information D5 is added so as not to be in the same state twice can be transmitted.
[0040]
Accordingly, the transmitting device 2 adds the identification information D5 generated as information that cannot be guessed at all by the third party's communication interfering device 4 and highly reliable information for the receiving device 3 to identify. An anti-jam packet BMPK can be transmitted.
[0041]
By the way, in the transmission process of the message processing unit 11, a predetermined identification information generation program stored in advance in a program storage memory (not shown) in the transmission device 2 is read and a work memory (not shown) in the transmission device 2 is read. The message processing unit 11 cooperates with the CPU (not shown) in the transmission device 2 developed above, and the transmission processing procedure will be described with reference to the following flowchart. I do.
[0042]
As shown in FIG. 6, upon receiving the request data DNa transmitted from the receiving device 3, the message processing unit 11 proceeds from the start step SP0 of the routine RT1 to the next step SP1.
[0043]
In step SP1, the message processing unit 11 switches the input path of, for example, the pseudorandom number D1 from the second filter unit 32 (FIG. 3) to the first filter unit 31 by the pseudorandom number input switching unit 30, and proceeds to the next step SP2. Move on.
[0044]
In step SP2, the message processing unit 11 generates the 32-bit pseudo-random number D1 by the pseudo-random number generation unit 20, and proceeds to the next step SP3.
[0045]
In step SP3, the message processing unit 11 generates a partial random number D3 by extracting the upper 16 bits of the pseudo-random number D1 of, for example, 32 bits by the first filter unit 31, and proceeds to the next step SP4.
[0046]
In step SP4, the message processing unit 11 increments the internal counter by "1" by the counter unit 21, generates a sequence number D2 corresponding to the current increment number of the internal counter, and proceeds to the next step SP5.
[0047]
In step SP5, the message processing unit 11 generates identification information D5 by adding the sequence number D2 generated in step SP4 to the head of the partial random number D3 generated in step SP3, and sends this to the packet generation unit 12. After giving, the process moves to the next step SP6.
[0048]
In step SP6, the message processing unit 11 determines whether or not the request data DNb requesting suspension of the service denial measure has been received.
[0049]
If an affirmative result is obtained here, this indicates that the receiving device 3 has stopped receiving the content change packet FPK or has reduced the number of received content change packets FPK. At this time, the message processing unit 11 Moves to the next step SP8, and terminates the identification information generation processing.
[0050]
On the other hand, if a negative result is obtained, this indicates that the number of receptions of the content change packet FPK (FIG. 1) is still large in the receiving device 3, and at this time, the message processing unit 11 proceeds to the next step SP7. Move to
[0051]
In step SP7, the message processing unit 11 determines whether the packet encryption processing in the packet generation unit 12 has been completed.
[0052]
If a negative result is obtained here, this means that the packet generation unit 12 has not yet executed the packet encryption processing on all the data pieces, and at this time, the message processing unit 11 determines in step SP2 Then, the pseudo random number D1 is generated again.
[0053]
On the other hand, if a negative result is obtained, this means that the packet generation unit 12 has already executed the packet encryption process on all data pieces, and at this time, the message processing unit 11 Moving to the next step SP8, the identification information generation processing ends.
[0054]
(3) Configuration of receiving device
As illustrated in FIG. 7, the receiving device 3 includes a communication unit 41, a packet input switching unit 42, a message determination unit 43, a packet decoding unit 44, and an attack measurement unit 45. The transmission packet PK, the interference countermeasure packet BMPK, or the content change packet FPK) is received and given to the packet input switching unit 42.
[0055]
When the packet input switching unit 42 receives the interference countermeasure start notification data D11 notified when requesting the start of the service denial countermeasure to the transmitting apparatus 2, the packet input switching unit 42 transmits the interference countermeasure packet BMPK ( The content change packet FPK) is provided to the message determination unit 43.
[0056]
On the other hand, when the packet input switching unit 42 receives the interruption countermeasure stop notification data D12 that is notified when the transmission unit 2 requests the transmission unit 2 to stop the service denial countermeasure, the packet transmission unit 42 transmits the transmission transmitted from the transmission unit 2. The packet PK (content change packet FPK) is provided to the packet decoding unit 44.
[0057]
The packet decoding unit 44 performs a packet decoding process on the transmission packet PK given from the packet input switching unit 42 or the message determination unit 43 in accordance with IPsec, which is the same communication protocol as the transmission side. When a decoding error such as a hash value to be obtained is not obtained or the like, a data fragment restored as a result of the decoding is stored in, for example, an internal memory (not shown).
[0058]
On the other hand, when a decoding error occurs, the packet decoding unit 44 determines that the content of the transmission packet PK is the changed content change packet FPK, discards the content change packet FPK, and, at the same time, discards the content change packet FPK. Is given to the attack measurement unit 45 as detection notification data D13.
[0059]
The attack measuring unit 45 has a counter, and every time it receives the detection notification data D13 given from the packet decoding unit 44 or the message determining unit 43, it sequentially increments the counter by “1”, (Hereinafter referred to as the number of unit attacks) is measured based on the internal clock.
[0060]
When the number of such unit attacks is large, the content modification packet FPK is received in large quantities when the numerical value is large, that is, the scale of the denial of service is large. Indicates that the scale of the act is relatively small.
[0061]
Here, when the unit attack count of the counter becomes larger than the predetermined threshold, the attack measuring unit 45 transmits request data DNa requesting start of a service denial measure to the transmitting device 2 via the communication unit 41, The anti-jamming start notification data D11 is provided to the packet input switching unit 42 and the message determination unit 43.
[0062]
On the other hand, when the unit attack count of the counter becomes smaller than the predetermined threshold, the attack measurement unit 45 transmits request data DNb requesting suspension of the service denial measure to the transmission device 2 via the communication unit 41. At the same time, the interruption countermeasure stop notification data D12 is given to the packet input switching unit 42 and the message determination unit 43.
[0063]
The message determination unit 43 executes various processes only during a period from when the interference countermeasure start notification data D11 is received to when the interference countermeasure stop notification data D12 is received (that is, a service denial countermeasure period).
[0064]
Therefore, the message determination unit 43 reduces its own processing load and power consumption, and as a result, can reduce the processing load and power consumption of the entire receiving device 3 as well.
[0065]
Upon receiving the interference countermeasure start notification data D11, the identification information detection section 51 of the message determination section 43 receives the interference countermeasure packet BMPK (FIG. 5) given from the packet input switching section 42.
[0066]
If the identification information D5 is not added to the interference countermeasure packet BMPK, the identification information detection unit 51 determines that the interference countermeasure packet BMPK is the content change packet FPK, discards the content change packet FPK, and , The detection notification data D13 is provided to the attack measurement unit 45.
[0067]
On the other hand, when the identification information D5 is added to the interference countermeasure packet BMPK (FIG. 5), the identification information detection unit 51 extracts the interference countermeasure packet BMPK from the information extraction unit 52, the sequence number extraction unit 53, and the validity. This is given to the sex test section 56.
[0068]
The information extraction unit 52 extracts a partial random number D3 (hash value D4) from the identification information D5 (FIG. 4) added to the interference countermeasure packet BMPK given from the identification information detection unit 51, and outputs the partial random number D3 (hash value D4). Give to.
[0069]
The sequence number extraction unit 53 extracts the sequence number D2 from the identification information D5 added to the interference countermeasure packet BMPK given from the identification information detection unit 51, and supplies the extracted sequence number D2 to the pseudorandom number generation unit 54.
[0070]
The pseudo-random number generation unit 54 has the same linear congruential generation method as the pseudo-random number generation unit 20 in the transmission device 2, and generates a 32-bit pseudo-random number D14 corresponding to the sequence number D2 given from the sequence number extraction unit 53. Then, this is given to the comparison information generation unit 55.
[0071]
The comparison information generation unit 55 has the same configuration as the configuration of the filter unit 22 described above with reference to FIG. 3, and every time the attack measurement unit 45 receives the interference countermeasure start notification data D11, the input switching in the filter unit 22 is performed. Corresponding to the first filter unit or the second filter unit.
[0072]
Then, the comparison information generation unit 55 generates a comparison partial random number D15 for comparison with the partial random number D3 by extracting, for example, the upper 16 bits of the 32-bit pseudo random number D14 given from the pseudo random number generation unit 54. Is given to the validity checker 56.
[0073]
The validity checking unit 56 collates the comparison partial random number D15 given from the comparison information generation unit 55 with the partial random number D3 given from the filter extraction unit 52.
[0074]
Here, when the judgment result does not match, the validity checking unit 56 determines that the interference countermeasure packet BMPK given from the identification information detecting unit 51 is actually a content change packet FPK in which the content of the packet has been changed. The determination is made, the content change packet FPK is discarded, and the detection notification data D13 is given to the attack measurement unit 45.
[0075]
On the other hand, when a matching determination result is obtained, the validity checking unit 56 discards only the identification information D5 in the interference countermeasure packet BMPK given from the identification information detecting unit 51, and obtains the transmission packet PK obtained as a result. To the packet decoding unit 44.
[0076]
As described above, the message determination unit 43 determines whether or not the identification information D5 is present before the packet decoding unit 44 decodes the identification information D5 based on the identification information D5 added to the transmission packet PK in an uncoded state. The content change packet FPK can be detected only by a simple process of determining whether D5 has the same collation result.
[0077]
Therefore, even when a large amount of content change packets FPK are received from the communication interfering device 4, the message determination unit 43 performs simple processing with a small processing load without decoding the large amount of content change packets FPK. The content change packet FPK can be discarded, so that the processing load on the receiving device 3 can be significantly reduced.
[0078]
By the way, in the identification information determination process of the message determination unit 43, an identification information determination program corresponding to the identification information generation program is stored in a program storage memory (not shown) in the receiving device 3 in advance. The CPU (not shown) in the receiving device 3 that has read and developed the program on a work memory (not shown) in the receiving device 3 and the message determination unit 43 cooperate with each other. The identification information determination processing procedure will be described with reference to the following flowchart.
[0079]
As shown in FIG. 8, when the message determination unit 43 receives the interference measure start notification data D11 from the attack measurement unit 45, the message determination unit 43 proceeds from the start step SP10 of the routine RT2 to the next step SP11.
[0080]
In step SP11, the message determination unit 43 determines whether or not the identification information detection unit 51 has received the anti-jamming packet BMPK.
[0081]
If a negative result is obtained here, this indicates that the interference countermeasure packet BMPK has not yet been received from the packet input switching unit 42. At this time, the message determination unit 43 waits until receiving the interference countermeasure packet BMPK. .
[0082]
On the other hand, if an affirmative result is obtained, this means that the interference countermeasure packet BMPK has been received from the packet input switching unit 42, and the message determining unit 43 proceeds to the next step SP12.
[0083]
In step SP12, the message determination unit 43 determines whether or not the identification information detection unit 51 adds identification information D5 (FIG. 5) to the interference countermeasure packet BMPK received in step SP11.
[0084]
If a negative result is obtained here, this means that the identification information D5 has not been added even though the transmission device 2 has requested the transmission device 2 to start service denial, so that the countermeasure packet BMPK received in step SP11 is actually This indicates that the packet is an illegal content change packet FPK in which the content of the transmission packet PK has been changed. At this time, the message determination unit 43 proceeds to the next step SP13.
[0085]
In step SP13, the message determination unit 43 discards the jamming countermeasure packet BMPK determined by the identification information detection unit 51 to be the content change packet FPK in step SP12 and provides the detection notification data D13 to the attack measurement unit 45. The process proceeds to the next step SP21.
[0086]
On the other hand, if a positive result is obtained in step SP12, this indicates that the jamming countermeasure packet BMPK received in step SP11 can be a truly valid packet candidate. At this time, the message determination unit 43 Move to the next step SP14.
[0087]
In step SP14, the message determination unit 43 causes the information extraction unit 52 to extract, for example, a partial random number D3 from the identification information D5 (FIG. 4) added to the interference countermeasure packet BMPK, and proceeds to the next step SP15.
[0088]
In step SP15, the message determination unit 43 extracts the sequence number D2 from the identification information D5 added to the interference countermeasure packet BMPK by the sequence number extraction unit 53, and proceeds to the next step SP16.
[0089]
In step SP16, the message determination unit 43 causes the pseudorandom number generation unit 54 to generate a 32-bit pseudorandom number D14 corresponding to the sequence number D2 extracted in step SP15, and proceeds to the next step SP17.
[0090]
In step SP17, the message determination unit 43 generates the comparison partial random number D15 by extracting the upper 16 bits of the 32-bit pseudo random number D14 generated in step SP16 by the comparison information generation unit 55. Move to step SP18.
[0091]
In step SP18, the message determining unit 43 determines whether or not the validity checking unit 56 matches the partial random number D3 extracted in step SP14 by comparing the partial random number D15 generated in step SP17 with the partial random number D15 for comparison. .
[0092]
If a positive result is obtained here, this means that the jamming countermeasure packet BMPK received in step SP11 is truly legitimate without any change in the contents of the packet. Then, the procedure moves to the next step SP19.
[0093]
In step SP19, the message judging unit 43 discards only the identification information D5 of the legitimate anti-jamming packet BMPK judged in step SP18 by the validity checking unit 56, and sends the transmission packet PK obtained as a result to the packet decoding unit 44. After giving, the process moves to the next step SP21.
[0094]
On the other hand, if a negative result is obtained in step SP18, it indicates that the anti-jamming packet BMPK received in step SP11 is actually an illegal content change packet FPK whose content is changed in this packet. At this time, the message determination unit 43 proceeds to the next step SP20.
[0095]
In step SP20, the message determining unit 43 discards the jamming countermeasure packet BMPK determined by the validity checking unit 56 to be the content change packet FPK in step SP18, and supplies the detection notification data D13 to the attack measuring unit 45. The process proceeds to the next step SP21.
[0096]
In step SP21, the message determination unit 43 determines whether or not the interference measure stop notification data D12 has been received from the attack measurement unit 45.
[0097]
Here, if a negative result is obtained, this indicates that the service interruption countermeasure period is still in progress, and thus the transmission device 2 is transmitting the interference prevention packet BMPK with the identification information D5 added. The determination unit 43 returns to step SP11 and waits for the anti-jamming packet BMPK again.
[0098]
On the other hand, if an affirmative result is obtained, this indicates that this is not a service denial-prevention period, and thus that the transmitting device 2 is transmitting a transmission packet PK to which the identification information D5 is not added. The unit 43 stops its operation and enters the sleep state, and proceeds to the next step SP22 to end the identification information determination process.
[0099]
(4) Operation and effect
In the above configuration, the message processing unit 11 generates the pseudorandom number D1 by using the derivation result derived by the pseudorandom number generation unit 20 based on predetermined information used in, for example, IPsec as a predetermined communication protocol.
[0100]
Next, the message processing unit 11 extracts the upper 16 bits of the pseudorandom number D1 by the filter unit 22 as signal processing for reducing the information amount of the pseudorandom number D1 generated by the pseudorandom number generation unit 20. Alternatively, the pseudo random number D1 is converted according to a predetermined one-way hash function algorithm to generate a partial random number D3 or a hash value D4 in which the state of the random number sequence in the pseudo random number D1 is changed.
[0101]
Therefore, the message processing unit 11 can generate the identification information D5 for a third party without knowing the correspondence between the pseudo random number D1 and the partial random number D3 (or the hash value D4). For example, if the pseudorandom number D1 is illegally obtained during transmission, the pseudorandom number D1 of the generation source cannot be obtained based on the partial random number D3 (or the hash value D4). The estimation of D1 can be prevented.
[0102]
In addition, the message processing unit 11 sets the input path to the first filter unit 31 that generates the partial random number D3 and the input path to the second filter unit 32 that generates the hash value D4 from the receiving device 3 as the receiving side. Is switched by the pseudorandom number input switching unit 30 every time there is a request, so that the partial random number D3 and the hash value D4 are generated alternately in response to a request from the receiving device 3, so that the data configuration Can be generated, and a third party can be further prevented from inferring the pseudorandom number D1.
[0103]
According to the above configuration, the pseudorandom number D1 is generated using the derivation result derived based on the predetermined information used in the predetermined communication protocol as a seed, and the information amount of the pseudorandom number D1 is compared with the pseudorandom number D1. Is generated to generate a partial random number D3 or a hash value D4 in which the state of the random number sequence in the pseudo random number D1 is changed, so that the partial random number D3 (or the hash value D4) is transmitted during the transmission. Even if it is obtained improperly, it is possible to prevent the guess of the pseudorandom number D1 that is the source of the partial random number D3 (or the hash value D4) based on the partial random number D3. Leakage can be further prevented.
[0104]
(5) Other embodiments
In the above embodiment, the partial random number D3 or the hash value D4 as the random number sequence change information is generated by reducing the information amount of the pseudo random number D1 generated by the pseudo random number generation unit 20 as the pseudo random number generation unit. Although the description has been given of the case where the filter unit 22 as the filter means is applied to the present invention, the present invention is not limited to this. For example, the information amount of the pseudorandom number D1 is increased, or a part of the pseudorandom number D1 is changed. Filter means for generating random number sequence change information by performing predetermined signal processing such as replacing other information or replacing corresponding portions of the pseudo random number D1 may be applied to the present invention. The point is that the random number generated by the pseudo random number generation means is subjected to predetermined signal processing to change the state of the random number sequence in the pseudo random number. The various other filter means for generating a sequence change information can be applied to the present invention.
[0105]
Further, in the above-described embodiment, every time there is a request from the receiving device 3 as a receiving side, a first filter means as a first filter means for generating a partial random number D3 by extracting a part of the pseudorandom number D1. A pseudo random number serving as an input switching means includes a filter unit 31 and a second filter unit 32 serving as a second filter unit that generates a hash value D4 by converting the pseudo random number D1 according to a predetermined one-way hash function algorithm. Although the case where switching is performed by the input switching unit 30 has been described, the present invention is not limited to this, and the following items may be adopted.
[0106]
1. The receiving device 3 requests switching between the first filter unit 31 and the second filter unit 32 by a predetermined command.
2. The filter unit 22 in the transmission device 2 is configured to include only the first filter unit 31, and the first filter unit 31 extracts a portion where the pseudorandom number D1 is extracted every time there is a request from the reception device 3. change.
3. In the configuration described in the above item 2, the receiving device 3 requests a change of an extraction location for extracting a part of the pseudorandom number D1 in the first filter unit 31 by a predetermined command.
4. The filter unit 22 in the transmission device 2 is configured to include only the first filter unit 31, and the first filter unit 31 changes the data length for extracting the pseudorandom number D1 every time there is a request from the reception device 3. .
5. In the configuration described in 4 above, the receiving device 3 requests the first filter unit 31 to change the data length for extracting the pseudorandom number D1 by a predetermined command.
6. The filter unit 22 in the transmission device 2 has only the second filter unit 32 having at least two one-way hash function algorithms, and the second filter unit 32 receives a request from the reception device 3 every time. The two or more one-way hash function algorithms are switched.
7. In the configuration described in the above item 6, the receiving device 3 requests switching of two or more one-way hash function algorithms in the second filter unit 32 by a predetermined command.
8. Various combinations of the items listed in 1 to 7 above.
[0107]
According to the items described above, different partial random numbers and hash values can be generated in response to requests from the receiving device 3, so that leakage of information to a third party can be significantly prevented. In addition, the configuration of the filter unit 22 or the entire transmission apparatus 2 is reduced in size by a part except for the configuration of the first filter unit 31 or the second filter unit 32 for some of the above 2 to 7 and 8. Can be
[0108]
Further, in the above-described embodiment, a case has been described in which the pseudo-random number D1 of 32 bits is generated. However, the present invention is not limited to this, and it is possible to generate a pseudo-random number of various other bits. Can be.
[0109]
Further, in the above-described embodiment, the case has been described where the pseudo random number D1 is converted in accordance with a predetermined one-way hash function algorithm for reducing the information amount of the random number sequence in the pseudo random number D1, but the present invention applies to this. The pseudorandom number D1 can be converted according to various other one-way function algorithms.
[0110]
Further, in the above-described embodiment, the first filter unit 31 that extracts a part of the pseudorandom number D1 and the second filter unit that uses a predetermined one-way hash function algorithm that reduces the information amount of the random number sequence in the pseudorandom number D1 are used. However, the present invention is not limited to this, and in addition to this, the third filter means using various other algorithms such as a common key encryption algorithm and a keyed hash algorithm May be provided.
[0111]
For example, an AES (Advanced Encryption Standard) defined by FIPS (Federal Information Processing Standard) -197 can be used as the common key encryption algorithm, and a keyed hash algorithm is, for example, RFC (Request formal). A keyed MD (Message Digest) 5 specified in 1828 can be used.
[0112]
Further, in the above-described embodiment, a case has been described where the request data DN is transmitted via the Internet 5 which is the same network as the transmission packet PK. However, the present invention is not limited to this, and the request data DN is not limited to this. And the transmission packet PK may be transmitted and received via different networks. The point is that when the reception device 3 requests the transmission device 2 to add the identification information JP to the transmission packet PK, the request is transmitted. The request method that the transmitting device 2 responds to can be selected.
[0113]
Further, in the above-described embodiment, the case where the present invention is applied to IPsec which is a communication protocol on the Internet 5 has been described. However, the present invention is not limited to this, and for example, a communication protocol on the Internet such as SSH, a LAN ( The present invention can be applied to various other communication protocols on other networks, such as a communication protocol on a local area network, a communication protocol on a satellite broadcast, or a communication protocol on a text broadcast.
[0114]
Further, in the above-described embodiment, the pseudo random number generation unit 20 and the filter unit 22 as the pseudo random number generation device are provided in the transmission device 2, and the transmission packet PK is identified by the pseudo random number generation unit 20 and the filter unit 22. However, the present invention is not limited to this, and may be used in various other devices in various other applications.
[0115]
Furthermore, in the above-described embodiment, the identification information generation processing in the message processing unit 11 (FIG. 2) is realized by the identification information generation program, and the identification information determination processing in the message determination unit 43 (FIG. 7) However, the present invention is not limited to this, and the entire processing of each unit in the transmission device 2 may be realized by the identification information generation program. May be realized by the identification information determination program, or the respective units may be realized by dedicated integrated circuits.
[0116]
Further, in the above-described embodiment, the identification information generation processing is executed in accordance with the identification information generation processing procedure described above with reference to FIG. 6 in accordance with the identification information generation program stored in advance in the program storage memory. Although the case where the identification information determination processing is executed in accordance with the identification information determination processing procedure described above with reference to FIG. 8 according to the information determination program has been described, the present invention is not limited thereto, and the identification information generation program and / or the identification information determination program The identification information generation processing and / or the identification information determination processing may be executed by installing the information processing apparatus from the stored program storage medium.
[0117]
In this case, as a program storage medium for installing the identification information generation program and / or the identification information determination program in the information processing apparatus to make it executable, for example, a flexible disk, CD-ROM (Compact Disk-Read Only Memory). In addition to a package medium such as a DVD (Digital Versatile Disc) or the like, a semiconductor memory or a magnetic disk in which a program is temporarily or permanently stored may be realized. As a means for storing the transmission program and / or the reception program in these program storage media, a wired or wireless communication medium such as a local area network, the Internet, or digital satellite broadcasting may be used, and various communication interfaces such as a router and a modem may be used. Alternatively, it may be stored via the Internet.
[0118]
【The invention's effect】
As described above, according to the present invention, a pseudorandom number is generated using a derivation result derived based on information used in a predetermined communication protocol as a seed, and a predetermined signal process is performed on the generated pseudorandom number. By performing this, random number sequence change information in which the state of the random number sequence in the pseudo random number is changed is generated.
[0119]
In this case, even if the random number sequence change information is obtained by a third party, the random number sequence change information changes the state of the random number sequence in the pseudo random number. Based on the column change information, it is possible to prevent the guess of the pseudo-random number that is the source of the change, and thus it is possible to further prevent the leakage of the information to a third party.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an overall configuration of a transmission / reception system to which the present invention is applied.
FIG. 2 is a block diagram illustrating a configuration of a transmission device.
FIG. 3 is a block diagram illustrating a configuration of a filter unit.
FIG. 4 is a schematic diagram illustrating a configuration of identification information.
FIG. 5 is a schematic diagram illustrating a configuration example of an anti-jamming packet.
FIG. 6 is a flowchart illustrating an identification information generation processing procedure;
FIG. 7 is a block diagram illustrating a configuration of a receiving device.
FIG. 8 is a flowchart illustrating an identification information determination processing procedure;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Transmission / reception system, 2 ... Transmission apparatus, 3 ... Receiving apparatus, 4 ... Communication disturbance apparatus, 11 ... Message processing part, 20, 54 ... Pseudorandom number generation part, 21 ... Counter part, 22 ... .., A filter section, 23 a message generation section, 30 a pseudorandom number input switching section, 31 a first filter section, 32 a second filter section, 43 a message determination section, 45 an attack measurement , An identification information detection unit, 52, an information extraction unit, 53, a sequence number extraction unit, 55, a comparison information generation unit, 56, a validity inspection unit.

Claims (8)

Pseudo-random number generation means for generating a pseudo-random number as a seed with a derivation result derived based on information used in a predetermined communication protocol,
Filter means for generating random number sequence change information in which the state of the random number sequence in the pseudo random number is changed by performing predetermined signal processing on the pseudo random number generated by the pseudo random number generation means. A pseudorandom number generator characterized by the above-mentioned. The filter means,
The pseudorandom number generation device according to claim 1, wherein the random number sequence change information is generated by reducing an information amount of the random number sequence in the pseudorandom number as the predetermined signal processing. The filter means,
2. The pseudorandom number generator according to claim 1, wherein a partial random number as the random number sequence change information is generated by extracting a part of the random number sequence in the pseudorandom number as the predetermined signal processing. The filter means,
The pseudorandom number generator according to claim 1, wherein the pseudorandom number is generated as the random number sequence change information by converting the pseudorandom number according to a predetermined one-way function algorithm as the predetermined signal processing. . The filter means,
First filter means for generating a partial random number as the random number sequence change information by extracting a part of the random number sequence in the pseudo random number as the predetermined signal processing;
A second filter unit configured to generate the hash value as the random number sequence change information by converting the pseudorandom number according to a predetermined one-way function algorithm as the predetermined signal processing;
2. The pseudorandom number generator according to claim 1, further comprising: a pseudorandom number input switching unit that switches input of the pseudorandom number to the first filter unit or the second filter unit in response to a request from a receiving side. . The filter means,
4. The pseudorandom number generation device according to claim 3, wherein an extraction location for extracting a part of the random number sequence in the pseudorandom number is changed according to a request from a receiving side. A first step of generating a pseudo-random number using a derivation result derived based on information used in a predetermined communication protocol as a seed,
A second step of performing predetermined signal processing on the pseudorandom number generated by the pseudorandom number generation means to generate random number sequence change information in which the state of the random number sequence in the pseudorandom number is changed. A pseudo-random number generation method. Pseudo-random number generation means for generating a pseudo-random number as a seed with a derivation result derived based on information used in a predetermined communication protocol,
Filter means for generating random number sequence change information in which the state of the random number sequence in the pseudo random number is changed by performing predetermined signal processing on the pseudo random number generated by the pseudo random number generation means,
A transmitting unit for transmitting, via a transmission path, the random number sequence change information generated by the filter unit as identification information of a transmission packet generated in accordance with the communication protocol.

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