JP2006024119A - Portable electronic device, random number generation method, and data processing method by random number - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable electronic device capable of generating random numbers in which sufficient random number nature is assured without requiring complicated hardware configuration for random number generation. <P>SOLUTION: The portable electronic device in one example of this invention is provided with a receiving means (101) for receiving radio wave including various commands, a generation means (102) for generating operating power on the basis of the radio wave received by the receiving means, a processing means (120) for generating the random numbers on the basis of time from the operating power to be generated by the generation means reaches a specified level to commands to be transmitted with predetermined time intervals are received and processing data on the basis of the random numbers, and a transmitting means (101) for transmitting the data processed by the processing means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a portable electronic device (IC card) having an IC chip that can be used as, for example, a transit ticket, a public certificate card, a credit card, or an employee card. The present invention also relates to a random number generation method in such a portable electronic device. Furthermore, the present invention relates to a data processing method using random numbers in such a portable electronic device.

  In recent years, portable electronic devices (IC cards) having IC chips that can be used as transportation tickets, public certificate cards, credit cards, and employee ID cards have been remarkable. Among them, portable electronic devices capable of wireless communication have also appeared. Card-shaped devices are known as portable electronic devices. In addition to card shapes, there are RF tags used for article management such as coin-type and capsule-type devices.

  Such a portable electronic device (hereinafter referred to as a wireless card), when reading and writing important information, is used to confirm that both the wireless card reader / writer and the wireless card have not been tampered with each other. Perform authentication. In order for the wireless card reader / writer to communicate simultaneously with a plurality of wireless cards, communication collision prevention processing is performed.

When performing mutual authentication or anti-collision processing, the wireless card uses a function for generating a random number. However, in general, seed data (initial value) is often required for processing for generating a random number. That is, it is necessary to prepare a function for generating seed data by hardware in the chip of the card (see Patent Document 1).
JP 2001-5384 A

  As described above, in order to generate a random number, there has been a problem that a function for generating seed data has to be prepared in hardware in the chip of the card.

  An object of the present invention is to solve the above-described problems, and can generate a random number with sufficient randomness without requiring a complicated hardware configuration for generating a random number. It is to provide a portable electronic device and a random number generation method. Another object of the present invention is to provide a data processing method using random numbers for processing data using random numbers generated by such a random number generating method.

  The portable electronic device, random number generation method, and data processing method using random numbers according to the present invention are configured as follows.

  (1) The portable electronic device of the present invention is generated by a receiving unit that receives radio waves including various commands, a generating unit that generates operating power based on the radio waves received by the receiving unit, and the generating unit. A random number is generated based on the time from when the operating power reaches a specified level until a command transmitted at a predetermined time interval is received, and processing means for processing the data based on the random number, and the processing means Transmitting means for transmitting data.

  (2) The random number generation method according to the present invention receives radio waves including various commands, generates operating power based on the received radio waves, and a predetermined time interval after the generated operating power reaches a specified level. Generate a random number based on the time it takes to receive the command sent in.

  (3) In the data processing method using random numbers according to the present invention, radio waves including various commands are received, operating power is generated based on the received radio waves, and predetermined power is generated after the generated operating power reaches a specified level. A random number is generated based on a time until a command transmitted at a time interval is received, data is processed based on the generated random number, and the processed data is transmitted.

  ADVANTAGE OF THE INVENTION According to this invention, the portable electronic device and random number generation method which can produce | generate the random number by which sufficient randomness was ensured without requiring the complicated hardware structure for random number generation can be provided. In addition, according to the present invention, it is possible to provide a data processing method using random numbers that processes data using random numbers generated by such a random number generation method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a block diagram showing a schematic configuration of a portable electronic device according to an example of the present invention. This portable electronic device is a portable information recording medium that can transmit and receive data wirelessly and has an IC chip. This portable electronic device can be applied to, for example, a transit ticket, a public certificate card, a credit card, and an employee card. Further, the portable electronic device of the present invention can be applied to an RF tag used for article management such as a coin type and a capsule type in addition to a card shape.

  As shown in FIG. 2, the portable electronic device, that is, the wireless card 100 includes an antenna 101, a power generation / supply circuit 102, a modem circuit 110, a data processing circuit 120, and a memory 130.

  The power generation / supply circuit 102 includes a diode bridge 103, a power smoothing capacitor 104, a constant voltage diode 105, and a function of supplying power to each unit.

  The antenna 101 of the wireless card 100 receives a transmission wave from the wireless card reader / writer 200, the modulation / demodulation circuit 110 demodulates the received signal, the data processing circuit 120 processes the demodulated data, and the memory 130 performs processing. Stored data is stored. The data processing circuit 120 processes the data stored in the memory 130 again, the modulation / demodulation circuit 110 modulates the processed data, and the antenna 101 transmits the modulation signal to the wireless card reader / writer 200.

  Further, since the wireless card 100 does not have a power source, an AC transmission wave from the wireless card reader / writer 200 is received by the antenna 101, and then rectified by the diode bridge 103 of the power generation / supply circuit 102, Smoothing is performed by the smoothing capacitor 104, and a constant voltage determined by the constant voltage diode 105 is extracted. The extracted voltage is supplied to each circuit as a power source necessary for the wireless card 100 to operate.

  Next, an example of random number generation processing for generating a random value will be described. FIG. 3 is a diagram illustrating an example of random number generation processing for generating random values.

  As shown in FIG. 3, the data processing circuit 120 calculates the random number seed data S (t) and other parameters necessary for random number generation (for example, A and B) by putting them in the function f of the random number generation process. Thus, a random value (Rnd) is generated.

Random number value (Rnd) = f (A, B, random seed data)
If the seed data of the random number is always the same value, the generated random value may be the same value or a value with low randomness. Therefore, when the random value is required to have a certain degree of randomness, the randomness of the seed data is required.

  Thus, the seed data of the random number is used as seed data for the time t from when the power supply smoothing capacitor 104 of the wireless card 100 is charged to a level necessary for the normal operation of the wireless card until the random number is calculated. That is, the seed data is generated based on the time t from when the operating power generated by the power generation / supply circuit 102 reaches the specified level until the command transmitted at a predetermined time interval is received and the random number generation is started. A random number is generated based on this kind of data.

  The time t may be used as it is. However, when the parameter is used as a random number parameter, for example, the time t needs to be matched with a predetermined format (number of digits) or to obtain further randomness of the seed data. Is substituted into the function S.

Random value (Rnd) = f (A, B, seed data S (t))
Next, referring to FIG. 1, it is confirmed that there is a random property of time t from when the power supply smoothing capacitor of the wireless card 100 is charged to a level necessary for normal operation of the wireless card until the random number calculation is started. This will be described below.

When the wireless card A first receives a transmission wave from the wireless card reader / writer 200, the wireless card power smoothing capacitor 104 is charged, and a level necessary for the wireless card to operate normally after _tc1 hours. Reach Vo. From this point, the time period t ₁ until receiving a command that needs to generate a random number by the transmission command of the radio card reader · writer 200.

When the wireless card B (wireless card B different from the wireless card A) is brought close to the wireless card reader / writer 200 at the same timing in the same environment as the wireless card A, the power smoothing capacitor mounted on the wireless card B The charging time (t _c2 ) of the wireless card B and the charging time (t _c1 ) of the wireless card A are different due to individual differences in capacitance values between the power supply smoothing capacitor 104 mounted on the wireless card A and the wireless card A. Therefore, time t ₂ is obtained instead of time t ₁ . That is, if the wireless card is different, different seed data (different times t ₁ and t ₂ ) can be obtained due to the influence of individual differences of various parts constituting each card.

Further, even if exactly the same wireless card A is used in the same environment, different timing to bring the wireless card A to the communicable area of the wireless card reader-writer 200 (the timing for holding up the card is shifted by t _s3) The time from when the wireless card A is in a normally operable state until the random number generation command is received is a time t ₃ different from the time t ₁ .

  From the above, it is considered that the time t has higher randomness due to the following factors.

1. Individual differences between wireless cards (capacitor capacity for power smoothing, etc.)
2. Power supply smoothing capacitor charging time difference 3. Wireless card reader / writer timing 4, wireless card reader / writer random number generation request command reception time difference 5. Wireless card reader / writer As described above, the wireless card 100 uses the power supply smoothing capacitor 104 existing in the wireless card 100 as seed data necessary for generating a random number. It has the function to generate | occur | produce with the charging time of this as a trigger.

  Next, a case where a previous random number value is used for seed data will be described with reference to FIG.

  As described above, in the wireless card 100, after the power smoothing capacitor 104 receives the transmission wave of the wireless card reader / writer 200 and the wireless card is charged in a state in which the wireless card can operate normally, the wireless card 100 receives a random number generation command. Is used as seed data for random number generation.

  However, once charging of the power smoothing capacitor 104 is completed and random number generation is performed, if the charging of the power smoothing capacitor 104 is not released again and there is a random number generation command, the same seed data S (t ) Is used, and the previously created random value is used as seed data.

  This is advantageous in that the random number value can be generated by the same scheme as described above, and the random number seed data is different from the previous time, so that the random number value has high randomness.

  As shown in FIG. 4, the wireless card 100 receives a random number generation command from the wireless card reader / writer 200 (ST01). It is confirmed whether the previously generated random number value exists in the memory (ST02). If the previously generated random number value is not stored in the memory, the seed data of the random number is set to S (t) as described above (ST03). ), A random value [Rnd = f (A, B, S (t))] is calculated (ST04). The calculated random value is stored in a memory (ST05), data is processed based on the random value (ST08), and the processed data is transmitted (ST09).

Also, it is confirmed whether the previously generated random number value exists in the memory (ST02). If the previous random number value is stored in the memory, the random number value Rnd _old previously stored in the memory is used as seed data for the random value. (ST06), and a random value [Rnd = f (A, B, Rnd _old )] is calculated (ST07). The calculated random value is stored in a memory (ST05), data is processed based on the random value (ST08), and the processed data is transmitted (ST09).

  When a random number generation command is issued again, a method of using the time after the power supply smoothing capacitor is first charged may be applied.

  According to the wireless card 100 described above, the following operational effects can be obtained.

  1. In the wireless card of the present invention, the time from when the smoothing capacitor of the power supply is sufficiently charged until the random number generation command is received is used as seed data or parameters for random numbers. In other words, it is only necessary to mount a power supply smoothing capacitor necessary for the basic configuration of the wireless card, and there is no need to provide a dedicated part, and the inside of the chip mounted on the wireless card is not complicated.

  2. Since the wireless card of the present invention does not require a dedicated function for generating seed data for generating random numbers, the cost of a chip mounted on the wireless card can be reduced.

  3. The wireless card of the present invention uses the time from when the power supply smoothing capacitor is charged to when the random number generation command is received as one of random number generation parameters, not only as random number seed data, It is possible to improve randomness.

  4. Since the wireless card of the present invention uses the random number value once generated as seed data, once the charging of the power supply smoothing capacitor is completed and random number generation is performed, the charging of the power supply smoothing capacitor is released again. First, when there is a random number generation command, random numbers can be generated using almost the same scheme.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

It is a figure for demonstrating the randomness property of the time after the capacitor | condenser for power supply smoothing of a radio | wireless card is charged to the level required for a normal operation | movement of a radio | wireless card until random number calculation is started. It is a block diagram which shows schematic structure of the portable electronic device which concerns on an example of this invention. It is a figure which shows an example of the random number generation process which produces | generates a random value. It is a flowchart for demonstrating the random number generation process including the case where the random value already produced | generated as seed data is used.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Wireless card, 101 ... Antenna, 102 ... Power generation / supply circuit, 103 ... Diode bridge, 104 ... Power source smoothing capacitor, 105 ... Constant voltage diode, 110 ... Modulation / demodulation circuit, 120 ... Data processing circuit, 130 ... Memory , 200 ... Wireless card reader / writer

Claims (8)

Receiving means for receiving radio waves including various commands;
Generating means for generating operating power based on the radio waves received by the receiving means;
Processing means for generating a random number based on a time from when the operating power generated by the generating means reaches a specified level until receiving a command transmitted at a predetermined time interval, and processing the data based on the random number;
Transmitting means for transmitting data processed by the processing means;
A portable electronic device comprising: Receiving means for receiving radio waves including various commands;
Generating means for generating operating power based on the radio waves received by the receiving means;
The time from when the operating power generated by the generating means reaches a specified level until a command transmitted at a predetermined time interval is received and random number generation is started is used as seed data for random number generation, and a random number is generated based on the seed data. And processing means for processing the data based on the random number;
Transmitting means for transmitting data processed by the processing means;
A portable electronic device comprising: Receiving means for receiving radio waves including various commands;
Generating means for generating operating power based on the radio waves received by the receiving means;
Storage means for storing the generated random number;
On the condition that no random number is stored in the storage unit, the random number is calculated based on the time from when the operating power generated by the generation unit reaches a specified level until the command transmitted at a predetermined time interval is received. First processing means for generating and processing data based on the random number;
A second processing means for generating a next random number based on the random number stored in the storage means on the condition that a random number is stored in the storage means, and processing data based on the next random number;
Transmitting means for transmitting the data processed by the first and second processing means;
A portable electronic device comprising: Receiving means for receiving radio waves including various commands;
Generating means for generating operating power based on the radio waves received by the receiving means;
Storage means for storing the generated random number;
On the condition that the random number is not stored in the storage unit, until the operating power generated by the generating unit reaches a specified level until a command transmitted at a predetermined time interval is received and random number generation is started. First processing means for setting time as seed data for random number generation, generating a random number based on the seed data, and processing the data based on the random number;
On the condition that a random number is stored in the storage means, the random number stored in the storage means is used as seed data for random number generation, the next random number is generated based on the seed data, and based on the next random number A second processing means for processing data;
Transmitting means for transmitting the data processed by the first and second processing means;
A portable electronic device comprising: Receive radio waves including various commands,
Generate operating power based on the received radio waves,
A random number is generated based on a time from when the generated operating power reaches a specified level until a command transmitted at a predetermined time interval is received.
A random number generation method characterized by that. Receive radio waves including various commands,
Generate operating power based on the received radio waves,
A random number is generated based on a time from when the generated operating power reaches a specified level until a command transmitted at a predetermined time interval is received, data is processed based on the generated random number, and the processed Send data,
A data processing method using random numbers. Receive radio waves including various commands,
Generate operating power based on the received radio waves,
On the condition that no random number is stored, a random number is generated based on a time from when the generated operating power reaches a specified level until a command transmitted at a predetermined time interval is received, and this random number is stored. And
On the condition that the random number is stored, the next random number is generated based on the stored random number, and the next random number is stored.
A random number generation method characterized by that. Receive radio waves including various commands,
Generate operating power based on the received radio waves,
On the condition that no random number is stored, a random number is generated based on a time from when the generated operating power reaches a specified level until a command transmitted at a predetermined time interval is received, and this random number is stored. And processing data based on the generated random number, sending the processed data,
Based on the stored random number, the next random number is generated based on the stored random number, the next random number is stored, the data is processed based on the generated next random number, and the processed Send data,
A data processing method using random numbers.

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