JP4700189B2 - Information receiver - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an information receiving apparatus applied to, for example, a digital broadcast receiving device.InRelated.
[0002]
[Prior art]
Various devices using a digital compressed image restoration device have begun to be put into practical use in digital broadcasting, DSM (Digital Storage Media), etc., using digital compression encoding technology for images that has been developed in recent years. In some cases, a smart card that can be attached to and detached from the receiver is used.
[0003]
Here, a configuration of a standard digital satellite broadcast receiver which is an example of a conventional digital broadcast receiver will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of such a digital satellite broadcast receiver.
[0004]
In FIG. 4, reference numeral 100 denotes a receiving antenna. A tuner unit 110 selectively demodulates a desired physical channel from an intermediate frequency from an antenna such as a BS or CS, and reproduces a digital code. Reference numeral 120 denotes a transport decoder (program decoding extraction means) that separates and extracts information for decoding a program and program information from the demodulated digital code sequence. An AV decoder 130 restores digitally compressed video and audio signals.
[0005]
Reference numeral 180 denotes a CRT (display device) that displays the restored program. Reference numeral 140 denotes a controller that controls the operation of each part of the receiver. A memory 150 stores necessary information such as a control program for the controller.
[0006]
Reference numeral 160 denotes a smart card, which holds a unique identification number for each receiver, a contract form of the receiver, and the like, and decrypts a cipher for realizing the limited reception function. Reference numerals 1000 and 1010 denote signal lines for communication between a normally detachable smart card and the receiver body, and indicate a smart card communication IO (Input Output) line and a smart card control signal, respectively.
[0007]
Next, the operation of the conventional information receiving apparatus configured as described above will be described by taking digital broadcast reception in CS or the like as an example.
[0008]
The program transmitted from the broadcasting station is decoded as a digital signal by the receiving antenna 100 and the tuner unit 110. The decoded digital signal includes a signal for decoding the program and information on the program itself. Usually, in the digital transceiver, the information for decrypting the program is acquired according to the contract status of the receiver held in the smart card 160, and the decrypted information is decrypted and encrypted for limited reception. In the transport decoder 120, the program is decoded. Further, the program information is restored by the AV decoding means 130 and reproduced by the television monitor 180 or the like.
[0009]
Here, the function for realizing the conditional access function, that is, the realization of the cryptanalysis, the contract information, etc. in the removable smart card facilitates ensuring confidentiality and changing the conditional access system. Because. Further, in order to realize the limited reception function, the receiver main body side and the smart card side always perform digital communication and decrypt information necessary for limited reception.
[0010]
[Problems to be solved by the invention]
However, with the development of computer technology in recent years, this digital communication information can be analyzed by incorporating it into a personal computer etc. instead of a smart card that is a data carrier medium for receiving and using transmitted information. It has become possible to realize functions equivalent to regular smart card functions with a personal computer or the like. For this reason, there is a problem that the possibility of illegally realizing the limited reception function is increasing.
[0011]
  In consideration of the above-described conventional problems, the present invention can suppress, for example, an unauthorized realization of the conditional access function that does not depend on the regular combination of the data carrier medium and the information receiving apparatus as described above. Information receiverTheThe purpose is to provide.
[0012]
[Means for Solving the Problems]
  In a first aspect of the present invention (corresponding to claim 1), the information is transmitted by mounting a data-carrying medium carrying information receiving data for receiving and using the transmitted information. An information receiving device capable of receiving and using information,
It is a signal for detecting a transient response characteristic in a transmission path between the signal generating means and the mounted data carrier medium.Signal generating means for generating a test signal and transmitting it to the mounted data carrier medium;
  The generated test signalTransient response characteristicsDetecting means for detecting
  DetectionComparison of the transient response characteristics of the test signal and the transient response characteristics of a regular data carrier medium prepared in advanceDetermining means for determining whether the loaded data carrier medium is a regular data carrier medium based on the result;,
HaveThis is an information receiving apparatus.
[0014]
  FirsttwoThe present invention (claims)2The transmission path is a serial signal line,
  The test signal is a step signal sent to the serial signal line,
  The detection means is a data flip-flop for detecting, as a logical value, a result of comparing the level of the test signal in the serial signal line with a predetermined value at a predetermined timing,
  The transient response characteristic is the logical value at the detected predetermined timing.oneIt is an information receiver of this invention.
[0015]
  FirstthreeThe present invention (claims)3The transmission path is a serial signal line,
  The test signal is a predetermined analog signal sent to the serial signal line,
  The detection means is an AD converter for converting the predetermined analog signal to be sent into a digital signal and detecting the analog characteristics thereof,
  The transient response characteristic is the detected analog characteristic.oneIt is an information receiver of this invention.
[0016]
  FirstFourThe present invention (claims)4The transmission path is a serial signal line,
  The test signal is a signal having a predetermined frequency and duty sent to the serial signal line,
  The detection means is a comparator for detecting a result of comparing the voltage level of the test signal in the serial signal line with a predetermined value as a logical value;
  The transient response characteristic is the detected logical value.oneIt is an information receiver of this invention.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
[0027]
(Embodiment 1)
First, the configuration of the information receiving apparatus according to the first embodiment will be described with reference to FIGS. 1 is a block diagram showing the configuration of the main part of the information receiving apparatus according to the first embodiment, FIG. 2 is a timing chart showing the operation of the pulse timing control means 300, and FIG. 3 is the operation of the main part of the information receiving apparatus. FIG.
[0028]
In FIG. 1, reference numeral 310 denotes a data flip-flop, which captures the logic level of the smart card serial signal line 1000 at the input trigger pulse timing. Reference numeral 300 denotes a pulse timing control means for delaying the input pulse signal for a predetermined time according to the setting from the controller 140.
[0029]
The smart card 160 corresponds to the data carrier medium of the present invention. The controller 140 corresponds to means including the signal generation means and the determination means of the present invention.
[0030]
In FIG. 2, the input pulse to Tin of the pulse timing control means 300 is shown at the top. Here, the delay parameter value from the controller 140 is set in Lin of the pulse timing control means 300.
[0031]
Using the CKin of the pulse timing control means 300 of FIG. 2 and the internal counter of the pulse timing control means 300, the pulse timing control means 300 delays the pulse input to Tin by the delay parameter value, and the pulse timing control means 300 It has a function to output as To output.
[0032]
Next, the principle of smart card authenticity determination, which is a feature of the present invention, will be described with reference to FIG. To do.
[0033]
The smart card authenticity determination is performed by inputting a step signal as shown in the second stage of FIG. 3 to the smart card communication IO line 1000 and its analog response signal waveform as shown in the third stage of FIG. It is done using.
[0034]
First, the operation in the case of a regular smart card indicated by the solid line of the smart card control IO line 1000 (enlarged view) in FIG. 3 will be described.
[0035]
As shown in the uppermost part of FIG. 3, the controller 140 outputs a pulse signal to Tin of the pulse timing control means 300 prior to step signal input to the smart card communication IO line 1000. At the same time, the controller 140 sets a delay amount, for example, as M clock (Ck) in Lin of the pulse timing control means 300.
[0036]
As a result, the pulse timing control means 300 outputs a pulse signal To delayed by M clocks as shown in the lowermost stage of FIG. The data flip-flop 310 acquires the voltage of the smart card communication IO line 1000 at the timing of the To pulse signal, as shown in the smart card communication IO line 1000 (enlarged view) in FIG. In this case, since the voltage level is higher than the threshold level of the data flip-flop 310, the data flip-flop 310 outputs a logic level H (High), as shown in FIG.
[0037]
Next, the controller 140 performs the same operation for the pulse timing control means 300 after setting the delay amount as the M-α clock.
[0038]
As a result, the pulse timing control means 300 outputs a pulse signal To delayed by M-α clocks as shown in FIG. The data flip-flop 310 acquires the voltage of the smart card communication IO line 1000 at the timing of the To pulse signal, as shown in the smart card communication IO line 1000 (enlarged view) in FIG. In this case, since the voltage level is lower than the threshold level of the data flip-flop 310, the data flip-flop 310 outputs a logic level L (Low) as shown in FIG.
[0039]
As is clear from the above description, M and α are a threshold value between a voltage value detected at a timing delayed by M clocks and a voltage value detected at a timing delayed by M-α clocks. It is set to be separated by level. By making such settings, it is possible to detect the difference between the analog response signal waveform when using the regular smart card described above and the analog response signal waveform when using the fake smart card described later with an inexpensive configuration. it can. Further, the detection is not limited to this, and such detection may be performed at a predetermined timing.
[0040]
Next, an operation in the case of a fake smart card indicated by a dotted line in the smart card control IO line 1000 (enlarged view) in FIG. 3 will be described.
[0041]
First, when the pulse signal To delayed by M clocks is output from the pulse timing control means 300, the smart card communication IO line 1000 of FIG. As shown in the figure, the voltage of the smart card communication IO line 1000 (in this case, the dotted line voltage of the fake smart card) is acquired at the timing of the To pulse signal. However, as shown in the figure, the voltage level is lower than the threshold level of the data flip-flop 310, unlike the case of the regular smart card indicated by the solid line in the figure. A logic level L (Low) is output.
[0042]
Next, the controller 140 performs the same operation for the pulse timing control means 300 after setting the delay amount as the M-α clock. As a result, the pulse timing control means 300 outputs a pulse signal To delayed by M-α clocks as shown in FIG. The data flip-flop 310 acquires the voltage of the smart card communication IO line 1000 at the timing of the To pulse signal, as shown in the smart card communication IO line 1000 (enlarged view) in FIG. In this case, as shown in the figure, since the same voltage level is lower than the threshold level of the data flip-flop 310, in the data flip-flop 310, as in the case of the regular smart card, the logic level L (Low). Will be output.
[0043]
When a smart card is functionally realized by a personal computer or the like, it usually causes a difference in additional capacity or the like due to a difference in physical circuit configuration, and in an analog response characteristic, a regular smart card like the above-mentioned fake smart card. And the difference occurs.
[0044]
Therefore, such an analog response characteristic is detected by inputting the step signal to the smart card communication IO line as described above, and measuring the same voltage after a certain period of time, and the normal card that has been held in advance. By comparing with the same response characteristic of
[0045]
As described above, in the information receiving apparatus according to the first embodiment, the use of a fake smart card can be automatically detected on the receiver body side with an inexpensive configuration, and the connection between the card and the receiver body is relaxed. Unauthorized viewing can be suppressed even in a non-card / unique case where a plurality of receivers can be used with a single card.
[0046]
(Embodiment 2)
Next, the configuration of the information receiving apparatus according to the second embodiment will be described with reference to FIGS. FIG. 5 is a block diagram showing a configuration of a main part of the information receiving apparatus according to Embodiment 2 of the present invention. FIG. 6 is a timing chart for explaining the operation of authenticating the smart card.
[0047]
In FIG. 5, reference numeral 200 denotes an AD (analog / digital) converter, which digitally converts the signal waveform of the smart card communication IO line 1000 under the control of the controller 140 and outputs the signal waveform to the second memory unit 210.
[0048]
Hereinafter, the operation of the information receiving apparatus according to the second embodiment will be described.
[0049]
In the smart card communication IO line 1000 of FIG. 5, as shown in the upper part of FIG. 6, communication is performed between the main controller and the smart card by a normal digital serial signal.
[0050]
On the other hand, when the smart card function is emulated by a personal computer or the like and illegal viewing is attempted, an analog signal different from the normal smart card is shown in the lower part of FIG. Showing change.
[0051]
Here, as shown in FIG. 5, the analog characteristics of the smart card communication IO line 1000 are measured and digitally converted by the AD converter 200 and recorded in the second memory 210. Then, the measured analog characteristics stored in the second memory 210 and the analog signal characteristics of the smart card communication IO line 1000 in the regular smart card previously recorded in the first memory 150 are converted into the controller 140. The authenticity of the smart card is determined by comparing with the above.
[0052]
As described above, in the information receiving apparatus according to the second embodiment, the analog characteristics of the smart card communication IO line are measured and converted into digital data at regular intervals under the control of the controller, and compared with the same characteristics of the regular smart card. In order to determine the authenticity of a smart card, a more robust conditional access system for a fake smart card is possible.
[0053]
(Embodiment 3)
Next, the configuration of the information receiving apparatus according to the third embodiment will be described with reference to FIG. FIG. 7 is a block diagram showing the configuration of the main part of the information receiving apparatus according to Embodiment 3 of the present invention.
[0054]
In FIG. 7, reference numeral 400 denotes a change-over switch that selects a normal communication signal and a test signal for smart card authenticity determination for the smart card communication IO line 1000. Reference numeral 410 denotes a division cycle, which divides and outputs a clock under the control of the controller 140. A comparator 420 compares the voltage value of the smart card communication IO line 1000 with a reference value, and outputs it as a logical value.
[0055]
Hereinafter, the operation of the information receiving apparatus according to the third embodiment will be described with reference to FIG. FIG. 8 is a timing diagram for explaining the operation of the information receiving apparatus.
[0056]
The change-over switch 400 is connected to the IO line side of the controller 140 when communicating with a normal smart card. When the authenticity of the smart card is determined, the controller 140 controls the control switch 400 as shown in FIG. Is connected to the frequency divider 410 as shown by a solid line.
[0057]
In the following, a description will be given of how smart card authenticity determination is performed when the changeover switch 400 is connected to the frequency divider 410 side.
[0058]
The upper part of FIG. 8 shows clock input to the minute period 410. At this time, as the setting of the frequency division ratio for the frequency divider 410, for example, as shown in the output T of the frequency division 410 in the figure, the low period M = 4 and the high period N = 3 of the output pulse are set. It shall be.
[0059]
At this time, the frequency division ratio in frequency divider 410 is M + N = 7, and the duty is N / (M + N) = 3/7. Further, the frequency of the input clock CK to the frequency divider 410 is set to f_CKThen, the frequency of the output T of the frequency divider 410 is f_CK/ (M + N) = f_CK/ 7.
[0060]
Then, the voltage of the smart card communication IO line 1000 gradually increases during the high period of the output T of the minute period 410 as shown in FIG. In FIG. 8, the state of this voltage increase is indicated by a solid line for a regular smart card and by a dotted line for a fake smart card. Although this voltage rise depends on the characteristic of the IO line 1000 for smart card communication, in practice, it shows a characteristic close to the first-order lag characteristic in a time of about several tens of nsec, but in FIG. It is shown by a straight line.
[0061]
At this time, as shown in FIG. 8, the comparator 420 compares the voltage of the smart card communication IO line 1000 with the threshold level, and outputs a logical value High when the voltage is higher than the threshold level. In FIG. 8, a regular smart card is indicated by a solid line, and a fake smart card is indicated by a dotted line.
[0062]
As shown in FIG. 7, the output logical value is input to the controller 140 and held together with the values of the frequency division ratios M and N set in the frequency divider 410 (in this case, M = 4, N = 3). The
[0063]
Next, it is assumed that the controller 140 sets a low period M = 5 and a high period N = 2 of the output pulse as setting of the frequency division ratio for the frequency divider 410.
[0064]
At this time, as shown in the figure, the smart card communication IO line 1000 gradually increases in voltage with respect to the high period of the output T of the frequency divider 410. The output pulse 410 becomes Low and the voltage drops. In FIG. 8, a regular smart card is indicated by a solid line, and a fake smart card is indicated by a dotted line.
[0065]
At this time, as shown in FIG. 8, the comparator 420 compares the voltage of the smart card communication IO line 1000 with a threshold level, and outputs a logic value High when the voltage is higher than the threshold level. In FIG. 8, a regular smart card is indicated by a solid line, and a fake smart card is indicated by a dotted line.
[0066]
Since M = 5 and N = 2 at the present time, in the case of a regular smart card, the voltage value is lower than the threshold level, so that the output logical value is always Low, but in the case of a fake smart card As shown by the dotted line in the figure, a high period is generated.
[0067]
As shown in FIG. 7, these signals are input to the controller 140 and held together with the values of the frequency division ratios M and N set in the frequency divider 410 (in this case, M = 5, N = 2).
[0068]
The controller 140 holds in advance the setting values for these frequency dividers 410 and the logical values of the comparators 420 obtained for these values for regular smart cards. Then, the controller 140 determines whether the smart card is true or false by comparing this with the actually measured result.
[0069]
As described above, the information receiving apparatus according to the third embodiment can automatically detect the use of a fake smart card on the receiver main body side with an inexpensive configuration, and can suppress unauthorized viewing.
[0070]
  (Embodiment 4)
  Next, the configuration of the information receiving apparatus according to the fourth embodiment will be described with reference to FIG. FIG. 9 shows the present invention.Inventions related toIt is a block diagram which shows the structure of the principal part of the information receiver by Embodiment 4 of this invention.
[0071]
  In FIG. 9, reference numeral 900 denotes a smart card, and the present invention is provided inside.Inventions related toThe main functional blocks regarding are shown. On the other hand, 1900 indicates the receiver body side, and the present invention is provided inside.Inventions related toThe main functional blocks regarding are shown.
[0072]
First, the configuration on the smart card 900 side will be described.
[0073]
Reference numeral 640 denotes a CPU which controls each functional block in the smart card as well as decrypting the encryption. Reference numeral 700 denotes timer means which generates a pulse signal at regular intervals under the control of the CPU 640. A pseudo random number generation unit 710 generates a pseudo random number signal that is a source of authentication confirmation. Reference numeral 740 denotes a change-over switch that switches a normal serial communication signal or authentication code for authentication to the smart card communication IO line. Reference numeral 720 denotes serial multiplexing means, which performs bidirectional signal control of serial signals on the smart card communication IO line. Reference numeral 810 denotes ID (individual authentication number) holding means for holding different IDs for each receiver, for example. Reference numeral 750 denotes an authentication function generating unit that generates an authentication function for the random number from the pseudo random number generating unit 710 using the ID holding unit 810 as a parameter. Reference numeral 760 denotes a comparison unit that compares the output from the authentication function generation unit 750 with the response signal from the receiver main body input from the smart card communication IO line. Reference numeral 800 denotes a power cut-off switch that cuts off power supply to the smart card 900 under the control of the CPU 640.
[0074]
Next, the internal configuration of the receiver main body 1900 will be described.
[0075]
Reference numerals 1720, 1750, and 1810 denote a serial multiplexing unit, an authentication function generation unit, and an ID (individual authentication number) holding unit, respectively, which have the same functions as the same functional block on the smart card side. Here, functional blocks for a normal operation not directly related to the authentication operation and a switch for switching to the normal operation are omitted.
[0076]
  The smart card 900 isDeData carrierIs an exampleThe The means including the authentication function generating means 750 and 1750 includes:RecognitionMeans including certificate code generating meansIs an exampleThe The means including the comparing means 760 isSizeMeansIs an exampleThe means including the power cut-off switch 800 isTheSwitch meansIs an exampleThe The means including the pseudo random number generation means 710 includes:DeData generation meansIs an exampleThe
[0077]
Hereinafter, the operation of the information receiving apparatus according to the fourth embodiment will be described.
[0078]
First, the changeover switch 740 is connected to the H side in the figure when communicating with a normal smart card under the control of the CPU 640, but when performing authentication between the smart card and the receiver body. Is connected to the L side as shown by the solid line in FIG.
[0079]
At this time, the timer 700 generates a pulse signal at regular intervals. Then, the pseudo random number generator 710 generates a pseudo random number value as a trigger of this pulse signal, and transmits the generated pseudo random number value to the receiver main body 1900 via the changeover switch 740 and the serial multiplexing means 720, and is also smart. The authentication function generation means 750 in the card 900 is input. The authentication function generation means 750 generates an authentication function using the ID output from the ID holding means 810 as a parameter, and generates an authentication code that is the value of the authentication function for the random number from the pseudo-random number generation means 710 and compares it. Tell to means 760.
[0080]
On the other hand, the pseudo random number signal transmitted to the receiver main body 1900 is connected to the authentication function generating means 1750 on the receiver main body 1900 side via the serial multiplexing means 1720. The authentication function generation unit 1750 generates an authentication function using the ID output from the ID holding unit 1810 as a parameter, and generates an authentication code that is the value of the authentication function for the random number from the pseudo-random number generation unit 710. The data is sent to the smart card 900 side via the multiplexing means 1720.
[0081]
Usually, since the ID held in the ID holding means 810 on the smart card 900 side matches the ID held in the ID holding means 1810 on the receiver main body 1900 side, an authentication function on the smart card 900 side is generated. The authentication code generated from the means 750 matches the authentication code generated from the authentication function generating means 1750 on the receiver body 1900 side. Therefore, since the comparison unit 760 determines that the card is a regular contract card as a result of the comparison, the power supply is not cut off by the power cut-off switch 800 via the CPU 640.
[0082]
However, (1) since the ID held in the ID holding means 810 on the smart card 900 side does not match the ID held in the ID holding means 1810 on the receiver main body 1900 side, the above two authentications are performed. If the codes do not match, or (2) there is no correct response from the receiver main body 1900 to the pseudo random number input for authentication from the smart card 900 due to malfunction of the device, the comparison means 760 Determines that the smart card has been illegally used. Then, power supply to the smart card is cut off by the power cut-off switch 800 via the CPU 640, and the smart card is disabled.
[0083]
As described above, in the information receiving apparatus according to the fourth embodiment, the smart card itself periodically checks its normal use using the authentication function, and when the normal use cannot be confirmed, the smart card itself Since the smart card is invalidated, it is possible to realize a conditional access system that is more robust against unauthorized viewing. As described above, in the information receiving apparatus according to the fourth embodiment, the smart card has a one-to-one correspondence with the information receiving apparatus, and unauthorized viewing is more effective in the case of a card unique that is resistant to damage such as card forgery. It can be surely suppressed.
[0084]
As is apparent from the above description, the present invention provides, for example, an information receiving apparatus having a functional block for receiving information signals to control the functional block and to determine the authenticity of a smart card. A controller that generates a transient response test signal to the serial I / O signal line of the smart card and acquires and analyzes the response signal, and a removable smart card for decoding confidential information for the purpose of limited reception, etc. The controller automatically determines whether a legitimate contract card or an illegally duplicated fake card is based on the transient response characteristics of the serial I / O signal line between the controllers of both cards and the smart card. It is characterized by this.
[0085]
Further, according to the present invention, in the determination of the transient response characteristic in the information receiving apparatus, the pulse timing control means for delaying and outputting the input pulse signal after the time set by the controller, and the timing of the input trigger signal A data flip-flop that acquires and holds data, and inputs a step signal for a transient response test from the controller to the serial signal line of the smart card, by changing the pulse delay amount in the pulse timing control means, a plurality of times. In addition, a transient response characteristic of the serial signal line of the smart card can be easily obtained by obtaining the logical value multiple times by the data flip-flop.
[0086]
The present invention also provides an AD (analog-digital) converter that converts an analog signal connected to a serial signal line of a smart card into a digital signal and a regular smart card in determining the transient response characteristic in the information receiving apparatus. First memory means for holding a transient response characteristic in a serial signal line of a smart card, and second memory means for holding a digital output signal of the AD converter, and the second memory means by the controller The authenticity of the smart card is determined by comparing the transient response characteristic held in the normal memory with the normal transient response characteristic previously held in the first memory means.
[0087]
In the determination of transient response characteristics in the information receiving apparatus,
A frequency divider that outputs a clock with a division ratio designated by the controller and a duty; a changeover switch that switches between normal communication with a smart card and a test signal input for a transient response test by control from the controller;
A comparator for determining the voltage level of the serial signal line of the smart card, and a plurality of test signals with different frequencies and duties are input to the serial signal line of the smart card by the control from the controller, The transient response characteristic of the serial signal line of the smart card is easily obtained by changing the logic signal output from the comparator.
[0088]
  In addition, the present inventionInventions related toIn an information receiving apparatus including a removable smart card for decoding confidential information for the purpose of limited reception or the like and having a functional block for receiving information signals, a pulse signal is provided in the smart card at regular intervals. Is supplied to the card by the CPU control in the smart card, the timer means for generating the ID, the ID (individual authentication code) holding means, the pseudo random number generating means, the authentication function generating means based on the ID A switch for shutting off the power supply, an ID holding means for holding the same ID (individual authentication code) as in the smart card on the receiving device side, and an authentication function generating means similar to that in the smart card; When authentication based on random numbers is performed between the smart card and the receiver, and a normal authentication result cannot be obtained, the CPU in the smart card By blocking the power supplied to the card, in which features that it has improved concealment of the smart card.
[0089]
  In addition,FirstIn the above embodiment, the first and second authentication function generating means are the authentication function generating means 750 provided on the smart card 900 side and the authentication function generating means 1750 provided on the receiver 1900 side, respectively. It was. As described above, by providing the authentication function generating means on both the smart card 900 side and the receiver 1900 side, it is possible to realize a limited reception system that is extremely robust against unauthorized viewing. This is because the pseudo-random number and the ID (individual authentication number) can be hacked relatively easily, but the authentication function F has the pseudo-random number as the first variable R and the ID (individual authentication number) as the second variable ID. This is because (R, ID) is not easily hacked. Therefore,RecognitionA system configuration in which the proof function generating means is provided only on one side of (1) the smart card 900 side or the receiver 1900 side, or (2) a system configuration not provided is also considered. However, in such a system configuration, there is a technical possibility that hacking can be easily performed, which is not technically different from the case where the comparison verification of only the ID is simply performed between the smart card 900 side and the receiver 1900 side. Is expensive.
[0090]
  Also,DeIn the above embodiment, the data generation means is the pseudo random number generation means 710 provided on the smart card 900 side, which generates pseudo random numbers at a predetermined timing by using the timer 700. But,DeThe data generator is not limited to this, and may be provided on the receiver 1900 side, for example. However, as described above, it is significant to use a secret authentication function. So, for example,DeThe data generator is not provided on either the smart card 900 side or the receiver 1900 side, and a system configuration in which a predetermined constant value is substituted for the first variable is also conceivable. Then, there is a high possibility that hacking is easily performed.
[0091]
The functions F (R, ID) corresponding to different IDs are desirably different from each other, but the frequency of occurrence of the same F (R, ID) with respect to the different IDs is sufficiently high. If it is low, a sufficient effect can be obtained. More specifically, for example, when the ID is a 10-digit serial number, even if F (R, ID ') is used as a simple authentication function using the lower 9-digit ID', it is practically equivalent. An effect is obtained.
[0092]
  Also,PlaceThe standard certification procedure is, in short,ratioThe determination may be based on the result of the comparison, but it is desirable that the determination be made at a predetermined timing, such as every several minutes, as in the above-described embodiment.
[0093]
Also,SizeIn the above embodiment, the determining means is means including the comparing means 760 provided on the smart card 900 side. But,SizeThe determination means is not limited to this, and may be provided on the receiver 1900 side, or may be provided on both the smart card 900 side and the receiver 1900 side.
[0094]
Also,TheIn the above embodiment, the switch means is the power cut-off switch 800 provided on the smart card 900 side. But,TheThe switch means is not limited to this. For example, the switch means may be provided on the receiver 1900 side, or may be provided on both the smart card 900 side and the receiver 1900 side.
[0095]
  Also,UpThe invention describedOr an invention related to the present inventionA medium carrying a program and / or data for causing a computer to execute all or part of the functions of all or part of the meansWhatReadable medium by a computer, and a medium in which the read program and / or data execute the function in cooperation with the computerIs an invention related to the present invention.It is.
[0097]
Data includes a data structure, a data format, a data type, and the like. The medium includes a recording medium such as a ROM, a transmission medium such as the Internet, and a transmission medium such as light, radio wave, and sound wave. The supported medium includes, for example, a recording medium that records a program and / or data, a transmission medium that transmits the program and / or data, and the like. For example, in the case of a recording medium such as a ROM, it can be read by a computer, and in the case of a transmission medium, the program and / or data to be transmitted can be transmitted. As a result, it can be handled by a computer. The information aggregate includes software such as programs and / or data, for example.
[0098]
  As described above, the present inventionOr an invention related to the present inventionThis configuration may be realized by software or hardware.
[0099]
As described above, according to the present invention, for example, a controller that performs generation of a transient response test signal to a serial input / output signal line of a smart card and obtains and analyzes a response signal to determine whether a smart card is true or false. And a removable smart card for decryption of confidential information for the purpose of limited reception, etc., to determine whether a legitimate contract card or an illegally duplicated fake card is detected. Based on the difference in transient response characteristics in the input / output signal line, it is characterized by being automatically performed by the controller, so that illegal viewing by digital signal emulation technology using a computer etc. that has been developed in recent years, This has the effect of realizing a more robust conditional access system.
[0100]
According to the present invention, for example, in the determination of the transient response characteristic in the information receiving apparatus, the pulse timing control means for delaying and outputting the input pulse signal after the time set by the controller, and the input trigger A data flip-flop that acquires and retains data at the timing of the signal, and changes the pulse delay amount in the pulse timing control means from the controller to the serial signal line of the smart card, thereby providing a transient response test step signal. Receiving multiple times and obtaining multiple times as a logical value by the data flip-flop, it is possible to easily obtain the transient response characteristic of the serial signal line of the smart card. Has the effect of realizing.
[0101]
Further, according to the present invention, for example, in the determination of the transient response characteristic in the information receiving apparatus, an AD (analog-digital) converter that converts an analog signal connected to the serial signal line of the smart card into a digital signal, First memory means for holding a transient response characteristic in a serial signal line of the smart card in the smart card, and second memory means for holding a digital output signal of the AD converter. By comparing the transient response characteristics held in the memory means 2 with the normal transient response characteristics held in the first memory means, the analog configuration of the normal smart card and the fake smart card can be obtained with an inexpensive configuration. It becomes possible to compare characteristic details, and a more robust conditional access system against unauthorized viewing It has the effect to achieve.
[0102]
Further, according to the present invention, for example, in the determination of the transient response characteristic in the information receiving apparatus, normal communication between the smart card and the frequency divider that outputs the clock at the frequency division ratio and duty specified by the controller And a switch for switching the test signal input for the transient response test by the control from the controller, and a comparator for determining the voltage level of the serial signal line of the smart card, and the frequency from the minute period by the control from the controller , By inputting multiple test signals with different duty to the serial signal line of the smart card and changing the logic signal output from the comparator, the same response characteristics can be easily simplified the transient response characteristics of the smart card serial signal line To obtain a robust reception against unauthorized viewing at a lower cost. It has the effect of realizing a machine.
[0103]
  In addition, the present inventionInventions related toFor example, in an information receiving apparatus including a removable smart card for decrypting confidential information for the purpose of limited reception or the like and having a functional block for receiving information signals, the smart card has a certain period of time. Timer means for generating a pulse signal every time, ID (individual authentication code) holding means, pseudorandom number generation means, authentication function generation means based on the ID, and CPU control in the smart card And a switch for shutting off the power supplied to the receiver, the receiving device side includes an ID holding means for holding the same ID (individual authentication code) as in the smart card, and an authentication function generating means similar to that in the smart card. Authenticate on the basis of random numbers between the smart card and the receiver at regular intervals, and if a normal authentication result cannot be obtained, By shutting off the power supplied to the card by the CPU in the card, the smart card itself periodically checks its regular use using an authentication function. Since the smart card is invalidated by itself, there is an effect that it is possible to realize a conditional access system that is more robust against unauthorized viewing.
[0104]
【The invention's effect】
As is apparent from the above description, the present invention has an advantage that it is possible to suppress an unauthorized realization of the limited reception function, which is not based on a regular combination of a data carrier medium and an information reception device, for example.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a main part of an information receiving apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a timing chart for explaining the operation of the information receiving apparatus according to the first embodiment of the present invention.
FIG. 3 is a timing diagram for explaining the operation of the main part of the information receiving apparatus according to Embodiment 1 of the present invention;
FIG. 4 is a block diagram showing a schematic configuration of a conventional information receiving apparatus.
FIG. 5 is a block diagram showing a configuration of a main part of an information receiving apparatus according to Embodiment 2 of the present invention.
FIG. 6 is a timing chart for explaining the operation of the main part of the information receiving apparatus according to the second embodiment of the present invention.
FIG. 7 is a block diagram showing a configuration of a main part of an information receiving apparatus according to Embodiment 3 of the present invention.
FIG. 8 is a timing chart for explaining the operation of the main part of the information receiving apparatus according to the third embodiment of the present invention.
FIG. 9Inventions related toThe block diagram which shows the structure of the principal part of the information receiver by Embodiment 4 of this invention
[Explanation of symbols]
  140 controller
  150 first memory
  160 Smart Card
  300 Pulse timing control means
  310 Data flip-flop
  1000 IO line for smart card communication
  1010 Smart card control signal

Claims (4)

An information receiving apparatus capable of receiving and using the transmitted information by mounting a data carrying medium carrying information receiving data for receiving and using the transmitted information. And
To generate a test signal, which is a signal for detecting a transient response characteristic in a transmission path between the signal generating means and the mounted data carrier medium, and to transmit the test signal to the attached data carrier medium side Signal generating means,
Detecting means for detecting a transient response characteristic of the generated test signal;
Based on the result of comparing the transient response characteristic of the detected test signal with the transient response characteristic of a regular data carrier medium prepared in advance, the loaded data carrier medium is a regular data carrier medium. Determination means for determining whether or not there is ;
An information receiving apparatus comprising: The transmission path is a serial signal line;
The test signal is a step signal sent to the serial signal line,
The detection means is a data flip-flop for detecting, as a logical value, a result of comparing the level of the test signal in the serial signal line with a predetermined value at a predetermined timing,
Wherein a transient response characteristic, the information receiving apparatus according to claim 1, characterized in that the said logic value at a predetermined timing to be the detection. The transmission path is a serial signal line;
The test signal is a predetermined analog signal sent to the serial signal line,
The detection means is an AD converter for converting the predetermined analog signal to be sent into a digital signal and detecting the analog characteristics thereof,
Wherein a transient response characteristic, the information receiving apparatus according to claim 1, characterized in that the analog characteristics which are the detection. The transmission path is a serial signal line;
The test signal is a signal having a predetermined frequency and duty sent to the serial signal line,
The detection means is a comparator for detecting a result of comparing the voltage level of the test signal in the serial signal line with a predetermined value as a logical value;
Wherein a transient response characteristic, the information receiving apparatus according to claim 1, characterized in that the logical value said detection.

Images