JP2005021660A - Game machine, and command communication method and command communication program for game machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an illegal conduct by transmitting ciphered commands from a main board to a sub-board in a game machine equipped with a main board which receives operation by a player to judge an inside lottery and prize winning and controls the game machine to dispense game media corresponding to prize winning and a sub-board which receives a command from the main board to inform a player of a result of the inside lottery and to execute various kinds of direction. <P>SOLUTION: This game machine is equipped with a key generating part which generates a key of a cipher and outputs the key, a cipher part which includes a command cipher processing part to receive a command from a main board to cipher and output the command based on the key of the generated cipher, a key managing part to keep the key of the cipher received from the key generating part, and a desiphering part including a decipher processing part which receives a ciphered command from the command cipher processing part to decipher the ciphered command based on the key of the kept cipher to transmit the deciphered command to the sub-board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gaming machine, a command communication method in a gaming machine, and a command communication program.

  Pachislot machines such as slot machines and pachinko machines have built-in microcomputers that control lottery, winning, payout, and production by programs. This type of gaming machine receives a player's operation, performs an internal lottery and a winning determination according to the lottery result, and also controls a game medium payout control according to the winning and a first processing unit (so-called main board) , A second processing unit (so-called sub-board) that receives a command generated by receiving a player's operation from the first processing unit, notifies the result of the internal lottery, and performs various effects. A block diagram of a conventional slot machine is shown in FIG.

  The sub-board 2 receives a command from the main board 1 and performs processing such as rendering according to the command. The flow of commands is only one from the main board 1 to the sub board 2, and conversely, no command or the like is issued from the sub board 2 to the main board 1.

  The main board 1 has a random number generation unit 20, a start switch 30, a stop switch 50, a reel drive unit 70, a reel position detection circuit 71, a hopper drive unit 80, and a medal detection for counting the number of medals paid out from the hopper 81. The part 82 is connected. A peripheral substrate (local substrate) such as a control substrate 200, a speaker substrate 201, and an LED substrate 202 of the liquid crystal display device 62 is connected to the sub substrate 2. Details of these will be described later.

  The liquid crystal display device 62, the speaker, the display lamp, and the like constitute an effect display device. This effect display device is for notifying a player of a prize or the like, or for teaching a user a specific small role with a certain action during a certain game during a so-called assist time (AT). is there. (Assist time (AT): Even if a specific small role is established, the player will not be refunded if the reels are not aligned. After the big bonus ends (or at the time of establishment) to ensure payout by the small role) Alternatively, a lottery of assist time is drawn at any other opportunity, and if this is won, the player is instructed to perform an operation to establish a specific small role for a certain game with some action)

  As with the AT, there is a gaming machine in which the weight of the winning rate is controlled by software on the sub-board 2 side. The sub-board 2 side is provided with a function for adjusting the protruding balls. Specifically, as described above, an instruction for obtaining a ball is displayed on the liquid crystal display device so that the player can easily obtain the ball if the player operates according to the instruction. This instruction is not always issued, but is issued in a specific case.

  By the way, there are those that try to exploit this function and get illegally. As shown in FIG. 6, it is always easy to attach an unauthorized device X to a cable or connector between the main board 1 and the sub board 2 and always issue an AT command originally issued in a specific case from this device X. You get a ball. The AT is designed so that even if it is won in the internal lottery, it cannot be won unless it is pushed in the pushing order, and this pushing order changes irregularly, so that it is not won so much. However, when an unauthorized device X is attached, the pressing order is notified every time and there is no loss of data. This is significantly unfair compared to the general player and may cause damage to the hall. Although it is only necessary to inspect the gaming machine and remove the unauthorized device, it is not preferable because the illegal activity continues until then. There is a limit to increasing the frequency of inspection of gaming machines.

  Communication between the main board 1 and the sub-board 2 was established by transmitting and receiving fixed numerical values (command system) decided in advance. This method is simple and preferable, but on the other hand, it is possible to easily analyze the command system, and as shown in FIG. 6, a relay board is illegally provided between the main board 1 and the sub board 2, and the player's benefit -There is also a problem that it is easy to intentionally manipulate the disadvantages.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a command system that is fundamentally difficult to analyze by incorporating a cryptographic element into a command between a main board and a sub board. That is. Even if it is analyzed, the purpose is to provide a gaming machine in which a relay board cannot be easily developed and is not easily targeted by fraudsters.

The gaming machine according to the present invention receives a player's operation, performs an internal lottery and a winning determination, and performs a game medium payout control in accordance with the winning, for example, a main processing unit (for example, the main board 1 in FIG. 2), In a gaming machine comprising a second processing unit (sub-board 2) that receives a command from the first processing unit and performs an effect including notification of the result of an internal lottery,
An encryption unit including a key generation unit that generates an encryption key and outputs the key, and a command encryption processing unit that receives a command from the first processing unit and encrypts and outputs the command based on the encryption key When,
A key management unit for storing a cryptographic key received from the key generation unit, a command encrypted from the command encryption processing unit, and decrypting the encrypted command based on the stored cryptographic key; A decoding unit including a command decoding processing unit to be sent to the second processing unit.

The gaming machine according to the present invention performs internal lottery and winning determination in response to a player's operation, and generates a cryptographic key and a first processing unit that controls payout of gaming media in accordance with winning. A key generation unit that outputs a command, and an encryption unit that includes a command encryption processing unit that receives a command from the first processing unit, encrypts the command based on the encryption key, and outputs the encrypted command. For example, the main board 1) of FIG.
A second processing unit that receives a command from the first processing unit and produces an effect including notification of an internal lottery result; a key management unit that stores a cryptographic key received from the key generation unit; and the command encryption process A second control device comprising: a decryption unit including a command decryption processing unit that receives the encrypted command from the unit, decrypts the encrypted command based on the stored encryption key, and sends the encrypted command to the second processing unit (Sub-substrate 2),
The encryption key is connected to be able to transmit from the first control device to the second control device.

  The gaming machine according to the present invention includes two processing units (main board 1 and sub board 2). As described above, either the encryption unit or the decryption unit may be provided externally or may be incorporated. Well, both are included in the present invention.

  The encryption unit further includes an activation unit that activates encryption key generation and transmission processing, and the activation unit activates the key generation unit at any timing when the power is turned on or for each game. Also good.

  For example, the encryption key specifies a bit shift amount, the command encryption processing unit rotates the command according to the encryption key, and the command decryption processing unit follows the encryption key. Rotate the encrypted command in the reverse direction.

  For example, the command encryption processing unit obtains an exclusive OR of the encryption key and the command, and the command decryption processing unit obtains an exclusive OR of the encryption key and the encrypted command.

The command encryption processing unit includes a delay unit that delays an encrypted output for a specified period, and a calculation unit that adds or subtracts the output of the delay unit to the command received from the first processing unit and outputs a calculation result; The encryption key may specify a delay period in the delay means.
Correspondingly, the command decryption processing unit subtracts the received encrypted command for a period corresponding to the encryption key, and subtracts the output of the delay means to the received encrypted command. Or a calculation unit that adds and outputs a calculation result.

The command encryption processing unit stores an encrypted output generated in accordance with the progress of the game and outputs the stored encrypted output according to a designation, and outputs the first storage unit to the first process. A first arithmetic unit that performs an operation including addition or subtraction on the command received from the unit and outputs the operation result;
The command decryption processing unit stores the received encrypted output and outputs the stored encrypted output in accordance with the designation, and subtracts the output of the second storage unit from the received encrypted output Or a second operation unit that performs an inverse operation including addition and outputs an operation result,
The first storage unit outputs an encrypted output stored according to the key of the key generation unit,
The second storage unit outputs an encrypted output stored in accordance with a key of the key management unit.
It should be noted that the encrypted output is preferably used to encrypt a specific command generated as the game progresses.

  The encryption key is, for example, a calculation result output from the first calculation unit or a command output from the first processing unit.

According to the present invention, an internal lottery and winning determination are performed in response to a player's operation, and a first processing unit that controls payout of game media in accordance with the winning, and an internal lottery in response to a command from the first processing unit. In a gaming machine comprising a second processing unit that produces an effect including a notification of the result,
A delay unit that delays the encrypted output for a predetermined period; and the command is encrypted and output by adding or subtracting the output of the delay unit to the command received from the first processing unit. An encryption unit including an arithmetic unit that supplies the output to the delay unit,
Delay means for delaying the encrypted command received from the encryption unit for a predetermined period; and the encrypted command by subtracting or adding the output of the delay means to the received encrypted command. A command decoding unit that decodes and sends the decoded data to the second processing unit.

The present invention performs internal lottery and winning determination in response to a player's operation, and delays the encrypted output for a predetermined period, and a first processing unit that controls payout of game media in accordance with winning. A delay unit and an arithmetic unit that encrypts and outputs the command by adding or subtracting the output of the delay unit to a command received from the first processing unit, and supplies the encrypted output to the delay unit. A first control device comprising: an encryption unit including:
A second processing unit that receives a command from the first processing unit and produces an effect including notification of an internal lottery result; a delay unit that delays an encrypted command received from the encryption unit; A second control device comprising: a command decryption unit that decrypts the encrypted command by subtracting or adding the output of the delay means to the received encrypted command and sends the command to the second processing unit; Prepared,
The encrypted command is connected so as to be transmitted from the first control device to the second control device.

According to the present invention, an internal lottery and winning determination are performed in response to a player's operation, and a first processing unit that controls payout of game media in accordance with the winning, and an internal lottery in response to a command from the first processing unit. In a gaming machine comprising a second processing unit that performs an effect including notification of a result, a command communication method from the first processing unit to the second processing unit,
A key generation processing step for generating a cryptographic key and outputting the key when a predetermined condition occurs; and
A command encryption processing step for receiving a command from the first processing unit and encrypting and outputting the command based on the encryption key;
A key update processing step for storing the received encryption key;
And a command decryption processing step of receiving the encrypted command and decrypting the encrypted command based on the stored encryption key.

Determining whether the command was decoded correctly;
And a step of discarding the command when the command is not correctly decoded.

According to the present invention, an internal lottery and winning determination are performed in response to a player's operation, and a first processing unit that controls payout of game media in accordance with the winning, and an internal lottery in response to a command from the first processing unit. In a gaming machine comprising a second processing unit that performs an effect including notification of a result, a command communication method from the first processing unit to the second processing unit,
Storing an encrypted command transmitted from the first processing unit to the second processing unit;
Adding or subtracting the transmitted encrypted command to the command received from the first processing unit, encrypting the command, and transmitting to the second processing unit;
Storing the received encrypted command;
And decrypting the received encrypted command by subtracting or adding the received encrypted command to the received encrypted command.

According to the present invention, an internal lottery and winning determination are performed in response to a player's operation, and a first processing unit that controls payout of game media in accordance with the winning, and an internal lottery in response to a command from the first processing unit. In a gaming machine comprising a second processing unit that performs an effect including notification of a result, a communication program for commands from the first processing unit to the second processing unit,
A key generation processing step for generating a cryptographic key and outputting the key when a predetermined condition occurs; and
A command communication program comprising: a command encryption processing step that receives a command from the first processing unit and encrypts and outputs the command based on the generated encryption key.

According to the present invention, an internal lottery and winning determination are performed in response to a player's operation, and a first processing unit that controls payout of game media in accordance with the winning, and an internal lottery in response to a command from the first processing unit. In a gaming machine comprising a second processing unit that performs an effect including notification of a result, a communication program for commands from the first processing unit to the second processing unit,
A key update processing step for storing the received encryption key;
A command communication program comprising: a command decryption processing step for receiving an encrypted command and decrypting the encrypted command based on a stored encryption key.

And determining whether the command has been correctly decoded;
And a step of discarding the command when the command is not correctly decoded.

The program according to the present invention is recorded on a recording medium, for example.
Examples of the medium include EPROM device, flash memory device, flexible disk, hard disk, magnetic tape, magneto-optical disk, CD (including CD-ROM and Video-CD), DVD (DVD-Video, DVD-ROM, DVD- RAM), ROM cartridge, RAM memory cartridge with battery backup, flash memory cartridge, nonvolatile RAM cartridge, and the like.

  In addition, a communication medium such as a wired communication medium such as a telephone line and a wireless communication medium such as a microwave line is included. The Internet is also included in the communication medium here.

  A medium is a medium in which information (mainly digital data, a program) is recorded by some physical means, and allows a processing device such as a computer or a dedicated processor to perform a predetermined function. is there.

  As described above, according to the present invention, since the encryption is performed when the command is transmitted from the main board to the sub-board, it is possible to prevent fraud.

Embodiment 1 of the Invention
A gaming machine according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a gaming machine (slot machine).
A player who wants to enjoy a game with the slot machine 10 first borrows a medal as a game medium from a medal lending machine (not shown) or the like, and inserts a medal directly into the medal insertion slot 100 of the medal insertion device. The medal slot 100 is provided at a substantially central position in front of the slot machine 10.

  The slot machine 10 has a square box-shaped housing 11. A square window-like display window 12 facing the player side is formed at the center and upper part of the casing 11. A symbol display window 13 through which the symbols 61 of the three rotary reels 40 can be seen is formed at the center of the display window 12 at the center. The bet switch 16 is a switch located below the rotary reel 40 and reduces the number of stored medals to replace medal insertion. The settlement switch 17 is a switch located obliquely below the rotating reel, and pays out the stored inserted medal. The start switch 30 is a lever positioned obliquely below the rotary reel 40 and starts driving the reel unit 60 on condition that a game medal is inserted or the bet switch 16 is inserted. The stop switch 50 is for stopping the driving of the reel unit 60. The reel unit 60 is composed of three rotating reels 40. Each rotary reel 40 includes a rotary drum made of synthetic resin and a tape-like reel tape 42 attached around the rotary drum. A plurality of (for example, 21) symbols 61 are displayed on the outer peripheral surface of the reel tape 42. Reference numeral 62 denotes a liquid crystal display unit for performing various effects.

  Inside the slot machine 10, although not shown, a control device for controlling the entire operation of the slot machine 10 is incorporated. Although not shown, the control device is configured around a CPU and includes a ROM, a RAM, an I / O, and the like. Then, the CPU operates by reading a program stored in the ROM, and controls the rotation and stop of the rotary reel 40 based on the operation of the start switch 30 and the stop switch 50, and also controls the display of lamps, speakers, and the like.

  The start switch 30 is a lever that is positioned obliquely below the rotary reel 40 as described above, on condition that a game medal is inserted or the bet switch 16 is inserted, or from the previous game at the time of “Replay” (Repay). This is for starting the driving of the reel unit 60 on condition that the predetermined time elapses.

  The stop switch 50 is for stopping the driving of the reel unit 60 as described above. Specifically, the stop switch 50 includes three switches corresponding to each rotary reel 40, and one stop switch 50 is disposed below each rotary reel 40. The operation of the stop switch 50 corresponding to the rotating reel 40 is set to stop the rotation of the corresponding rotating reel 40.

  When the start switch 30 is operated on the condition that the medal is inserted or the bet switch 16 is inserted, or on the condition that a predetermined time has elapsed from the previous game at the time of “replay”, the reel unit 60 is driven, and the three units The rotating reel 40 starts to rotate. Thereafter, when one of the stop switches 50 is operated, the rotation of the corresponding rotary reel 40 is stopped. When all three stop switches 50 are operated, the rotation of the three rotary reels 40 is stopped. At this time, when a preset symbol 61 stops on the effective pay line of the display window 12, a predetermined number of medals are paid out through a hopper unit (not shown). In addition, you may credit instead of paying out medals.

  When the above-described control device controls the rotation and stop of the rotary reel 40 based on the operation of the start switch 30 and the stop switch 50, a prize is awarded for determining whether or not to win based on a predetermined lottery probability. Includes lottery means. A winning flag is established when the lottery result by the winning lottery means is a winning, and a winning is achieved on the condition that the combination of the stopped symbols of the rotating reel 40 matches a predetermined winning symbol while the winning flag is established. It is determined so that the player is given a medal or a special game.

  FIG. 2 is a block diagram showing an electrical schematic structure of the slot machine 10. In this figure, the display about the power supply system is omitted. The slot machine 10 includes a main substrate 1 (first control device) and a sub substrate 2 (second control device) that receives a command from the main substrate 1 and operates as a main processing device.

  The main board 1 is for performing an internal lottery in response to a player's operation, and processing such as reel rotation / stop and medal payout. The main board 1 includes a CPU that performs a control operation according to a preset program, and ROM and RAM that are storage means.

  The sub-board 2 is for receiving a command signal from the main board 1 and notifying the result of the internal lottery and performing various effects. The sub-board 2 includes a CPU that performs a control operation according to a preset program, and a ROM and a RAM that are storage means.

  The sub-board 2 receives a command from the main board 1 and performs processing such as rendering according to the command. The flow of commands is only one from the main board 1 to the sub board 2, and conversely, no command or the like is issued from the sub board 2 to the main board 1.

  When the command is transmitted from the main board 1 to the sub-board 2, the encryption processing unit 3 and the decryption processing unit 4 perform encryption processing and decryption processing of the command. The encryption processing unit 3 includes an activation unit 3a that activates encryption key generation and output processing, a key generation unit 3b that arbitrarily generates an encryption key, and encrypts a command based on the selected encryption key. A command encryption processing unit for transmitting to the substrate 2. The decryption processing unit 4 stores the encryption key received from the main board 1 and updates it to the latest one, and a command decryption process for decrypting the encrypted command based on the stored encryption key Part 4b. Details of these processes will be described later.

  The key generation unit 3b, for example, randomly determines the selection of keys based on the lottery result, or sets a plurality of keys in advance (for example, having a plurality of keys in a table format). A key is specified and generated unpredictably by sequentially selecting the key in a regular order (for example, an address for accessing the table is randomly generated). Alternatively, a known method of taking a part of the quotient of the division result between prime numbers (for example, after the decimal point) or obtaining a remainder (remainder) of division between prime numbers can be used. Alternatively, the counter may be operated continuously, and data generated by the counter may be extracted under a predetermined condition (for example, operation of the start switch 30). In addition, a known algorithm (Monte Carlo method or the like) can be used, or a physical random number using thermal noise can be used. It is desirable that the keys are generated at random and the probability distribution is uniform (no deviation), but in practice, each key may be generated at a predetermined rate.

  In FIG. 2, the encryption processing unit 3 and the decryption processing unit 4 are represented by hardware images added to the main board 1 and the sub board 2, respectively, but the present invention is not limited to this. The encryption processing unit and the decryption processing unit may be built in the main substrate 1 and the sub substrate 2, or may be realized by programs of the main substrate 1 and the sub substrate 2, respectively.

  The main board 1 has a random number generation unit 20, a start switch 30, a stop switch 50, a reel drive unit 70, a reel position detection circuit 71, a hopper drive unit 80, and a medal detection for counting the number of medals paid out from the hopper 81. The part 82 is connected. A peripheral substrate (local substrate) such as a control substrate 200, a speaker substrate 201, and an LED substrate 202 of the liquid crystal display device 62 is connected to the sub substrate 2. Hereinafter, these peripheral substrates / devices except for the start switch 30 and the stop switch 50 will be described.

  The random number generation unit 20 includes a random number generation function that generates a certain range of random numbers, and a sampling function that extracts an arbitrary random number from the generated random numbers. As a specific example, it is composed of a counter and a latch.

  The reel driving unit 70 is a circuit that drives a stepping motor (not shown) that rotationally drives the three reels 40. Each stepping motor is subjected to 1-2 phase excitation by the reel drive circuit 70 and rotates once when a drive signal having a predetermined number of pulses is supplied.

  The reel position detection circuit 71 is provided in the vicinity of the reel 40, receives an output pulse signal from a photo sensor (not shown) for detecting the rotation position of the reel 40, detects the rotation position of each of the three reels 40, and detects the detection signal. Is output. A photo sensor (not shown) detects a shielding plate provided on each reel 40 and generates a reset pulse every time each reel 40 rotates once. This reset pulse is given to the CPU of the main board 1 via the reel position detection circuit 71. In the RAM of the main board 1, a count value corresponding to the rotation position within one rotation range is stored for each reel 40, and when the CPU receives the reset pulse, the count value formed in the RAM is stored. Clear to "0". By this clearing process, the deviation generated between the movement display of each symbol and the rotation of each stepping motor is eliminated every rotation.

  The hopper driving unit 80 is a circuit that drives a motor of the hopper 81 that stores medals and pays out the designated number of medals.

  The medal detection unit 82 is for counting the number of medals paid out from the hopper 81. When the medal count value actually paid out received from the medal detection unit 82 reaches the predetermined payout number data, the CPU of the main board 1 stops the driving by the hopper driving unit 80 and ends the medal payout. . The hopper drive circuit 80 and the medal detection unit 82 pay out a predetermined number of medals to the player based on the game result.

The liquid crystal control board 200 is a circuit for driving the liquid crystal display unit 62.
The speaker board 201 is a circuit for driving a loudspeaker (not shown).
The LED substrate 202 is a circuit for driving a display lamp and a back lamp (not shown).

  The liquid crystal display device 62, a speaker and a display lamp (not shown), etc. constitute an effect display device. This effect display device is for notifying a player of a prize or the like, or for teaching a user a specific small role during a certain game with some action during a so-called assist time (AT).

  The ROM of the main board 1 stores game processing procedures executed in the slot machine 10 as a sequence program, and stores a winning probability table, a symbol table, a winning symbol combination table, and the like. Has been. The winning probability table is divided so as to divide the random number extracted by the random number generator 20 into each winning mode, and stores data for dividing a predetermined range of random numbers generated by the random number generating unit 20 into each winning mode. ing. That is, the winning probability table has an area divided for each winning mode corresponding to the entire area of random numbers taken by the random number generator 20. For example, a range of 0 to a certain number is divided into a plurality, one division (area) is excluded, and the other division (area) is set as winning 1, winning 2,. The extracted random number data is collated with each of the winning determination area data divided for each winning mode in the entire random number area taken by the random number generator 20, and the winning corresponding to the winning mode to which the extracted random number data belongs is determined. Is done. For example, it is determined which category (region) of the winning probability table 5 the extracted random number value belongs to, and if the category is, for example, a category of winning 1, it is determined as “winning 1”. Similarly, if the extracted random number value belongs to an out-of-range category (region) in the winning determination table 5, it is determined as “out”. For example, when the evaluation of the lottery process is out of place, it is set so that the predetermined symbols are not aligned (so-called kicking), and when winning, the predetermined symbols are aligned on the condition that the stop switch is pressed at a predetermined timing. (So-called pull-in). And if predetermined symbols are prepared, medals corresponding to winning symbols are paid out. Since various types of winning are generated with the probability according to the data setting of the winning probability table, for example, the total medal within the business hours of the day is not influenced by the skill of the player. The payment rate is kept almost constant.

  In FIG. 2, X is an unauthorized device attached to the gaming machine by an unauthorized person. The unauthorized device X is often provided on a cable or connector connecting the main board 1 and the sub board 2. The unauthorized device X sends a command for notifying the sub-board 2 of information advantageous to the player to the sub-board 2 illegally (regardless of the processing of the main board 1). Since the purpose is not to interfere with the game processing, even if there is an unauthorized device X, command transmission from the main board 1 to the sub board 2 is normally performed except for the above points. Hereinafter, the operation of the gaming machine according to the embodiment of the present invention will be described with reference to FIGS. 3 and 4 on the assumption that the unauthorized device X is attached.

  FIG. 3 is a flowchart showing a procedure for generating an encryption key, and FIG. 4 is a flowchart showing an encryption process and a decryption process performed on the main board 1 and the sub board 2 based on the encryption key.

  The process of FIG. 3 is started by turning on the gaming machine or starting the game.

(Operation of main board 1)
S10: It is determined whether it is the timing at which the activation unit 3a newly generates or changes an encryption key. As conditions for extracting the encryption key, (a) when the power is turned on, (b) a predetermined timing for each game, for example, when the index of the first reel is detected, etc. are conceivable. If this timing is different for each model, fraudulent acts are difficult. If the key extraction condition is met (YES), the process proceeds to S11: key generation processing. Otherwise, S13: The normal game process is started.

S11: A cryptographic key is generated. The cryptographic key is disposable and preferably irregular (random). The generated key is stored in the memory. An encryption key can be obtained by using the random number generator 20 or a similar device or counter. For example, when a key extraction condition is detected, the counter value is latched, and the value is used as an encryption key. A cryptographic key suitable for the type of encryption used is generated. An example is shown below.

(1) Bit-shift encryption key This uses rotation, which is an operation performed on data in a register of the CPU. Rotation is an operation that shifts all bits in a register one bit to the left or right, and moves it to the opposite end of the register when the last bit is shifted out of the register. When a command is encrypted by bit shift, a numerical value indicating the shift amount is used as an encryption key. For example, when an 8-bit command is right-shifted (or left-shifted) in accordance with the encryption key in the encryption process and is left-shifted (or right-shifted) by the same amount in the decryption process, the encryption key is 3-bit data. The encryption key takes an arbitrary value from 0 to 7, but 011 means that the command is shifted by 3 bits. The shift direction is determined in advance. If the shift direction is different for each model, fraudulent acts are difficult.

(2) Scramble encryption key When encrypting a command by computing it with an encryption key, the encryption key is a random number having the same number of bits as the command. As the type of operation, addition / subtraction or exclusive OR (XOR) can be used. When the command is 8 bits, the encryption key takes an arbitrary value from 0 to 255. For example, 01111110 (hexadecimal: 7E).

S 12: The generated encryption key is transmitted to the sub-board 2. When the number of bits of the encryption key is small as in (1), an encryption key is assigned to a predetermined bit position, and an arbitrary numerical value is set to the other bit positions. When the number of bits of the encryption key is the same as the number of bits of the command as in (2), the encryption key is sent as it is.

  By the way, when an unauthorized device X is attached, it is not impossible for the device to read the encryption key. However, even if read, the encryption according to the embodiment of the present invention is effective. This is because it is impossible to determine the encryption algorithm from the encryption key, and thus the command cannot be encrypted correctly. If an unauthorized device X has an advanced analysis function, it is not impossible to analyze the encryption algorithm by performing statistical processing, but it is difficult to develop and install such an unauthorized device X. It is considered that the person hesitates to cheat on the gaming machine that is encrypting. If the cryptographic key is updated frequently, the analysis becomes more difficult.

S13: A normal game is started.

(Operation of sub-board 2)
S21: Receive a command. The command includes the generated encryption key in addition to the normal command.

S22: It is determined whether the received command is an encryption key. As a determination method, before sending the encryption key, a command to that effect (eg, hexadecimal: F0) is sent and then the encryption key is sent, or the encryption command is sent multiple times in succession and the same command is given. When it is received more than the number of times, it is considered that it is a cryptographic key, the key command is a method of completing three messages, and the encryption key is always used in the specific processing performed simultaneously by the main board 1 and the sub board 2 such as initialization processing after power-on. The way of sending, etc. can be considered. If it is not an encryption key (NO), it is considered to be a normal command, so that the command is delivered to the CPU to execute normal processing. Then, S21: The command reception process is repeated.

S23: If the received command is an encryption key, the command is stored in the RAM. If there is an old encryption key, discard it (simply overwrite). Then, S21: The command reception process is repeated.

  Next, encryption processing and decryption processing performed on the main board 1 and the sub board 2 will be described with reference to FIG.

(Operation of main board 1)
S31: A normal command is generated.

S32: The command is encrypted based on the encryption key. An example of encryption is shown below.
(1) Bit shift encryption The command is shifted right (or left) as specified by the encryption key. For example, when the encryption key is 011 and the shift direction is right, the 8-bit command 10101011 (hexadecimal: AB) is converted to 01110101 (hexadecimal: 75).

(2) Scramble encryption Encrypts a command by computing it with an encryption key. For example, when the encryption key is 01111110 (hexadecimal: 7E) and the arithmetic expression is XOR, the 8-bit command 10101101 (hexadecimal: AB) is converted to 11010101 (hexadecimal: D5).
Thereafter, the player receives an operation in accordance with the normal operation of the gaming machine, makes a winning determination, and pays out a medal when winning.

(Operation of sub-board 2)
S40: Decrypt the command based on the stored encryption key.
(1) Bit-shift cipher The received cipher command is shifted in the reverse direction only as specified by the cipher key. For example, when the encryption key is 011 and the shift direction is right, the encryption command 01110101 (hexadecimal: 75) is decrypted into the command 10101011 (hexadecimal: AB).

(2) Scramble encryption Encrypts a command by computing it with an encryption key.
For example, when the encryption key is 01111110 (hexadecimal: 7E) and the arithmetic expression is XOR, the encryption command 11010101 (hexadecimal: D5) is decrypted into the command 10101011 (hexadecimal: AB).

S41: It is determined whether the decryption has been correctly performed. If it is not decoded correctly (NO), the command is discarded. When it is correctly decoded (YES), the command is executed (S43), and for example, advantageous information is provided to the player (such as notification of the pushing order at the AT) (S44).

  Whether or not the decryption can be correctly performed can be determined by determining whether or not the decrypted command is correct. If the decrypted command is executable, it can be determined to be correct, and if the decrypted command is meaningless, the command is ignored. For example, when an unauthorized device X illegally sends 10101101 (hexadecimal: AB) as a command, the command is converted as follows in the sub-board 2 (a command that is not encrypted in the command decryption unit 4). Will be entered).

(1) Bit shift cipher For example, when the cipher key is 011 and the shift direction is right, the command 10101101 (hexadecimal: AB) is converted to 01011101 (hexadecimal: 57). Such commands do not exist and are ignored.

(2) Scramble encryption For example, when the encryption key is 01111110 (hexadecimal: 7E) and the arithmetic expression is XOR, the command 101010111 (hexadecimal: AB) is converted to 11010101 (hexadecimal: D5). Such commands do not exist and are ignored.

  Next, an outline of the operation of the slot machine having the above configuration will be described using the flow shown in FIG.

First, in step S1 shown in FIG. 5, when the start switch 30 is operated, the start switch 30 is turned on. Then, the process proceeds to the next step S2.
In step S2, a lottery process is performed by the main board 1. Then, the process proceeds to the next step S3.

In step S3, the rotation of the rotary reel 40 is started. Then, the process proceeds to the next step S4.
In step S4, when the stop switch 50 is operated, the stop switch 50 is turned on. Then, the process proceeds to the next step S5.
In step S5, rotation stop processing for the rotary reel 40 is performed. Then, the process proceeds to the next step S6.

In step S6, it is determined whether or not the operation of the stop switch 50 corresponding to the three rotary reels 40 has been performed. When it is determined that the operation of the stop switch 50 corresponding to the three rotary reels 40 has been performed, the process proceeds to the next step S7.
In step S7, it is determined whether or not the winning symbols corresponding to the winning flag are aligned on the effective winning line while the winning flag is established, that is, whether or not the winning is confirmed. If it is determined that the winning is confirmed, the process proceeds to the next step S8.

In step S8, medals corresponding to winning symbols are paid out. Then, the process proceeds to next Step S9.
In step S9, when a winning decision is made for a special game of the BB game or RB game, the number of winning decisions for the special game is incremented by one.

  As described above, according to the first embodiment of the present invention, since encryption is performed when a command is sent from the main board to the sub board, even if an unauthorized device is added, the illegal action is difficult. It can be effectively prevented.

  Furthermore, changing the transmission timing of the key command for each model makes it difficult for a third party to analyze and makes it difficult to perform fraud. For example, a key command is transmitted when the power is turned on in a certain model, and a key command is transmitted every time a first reel index in a normal game is detected in another model. In this way, if the timing is changed for each model, it becomes difficult to perform an illegal act.

  The encryption mechanism is very simple and can produce great effects. For example, it is possible to use a method of rotating transmission data (either left or right) or scrambling with a keyword based on a lottery result of 3 bits (if 3 bits, it can correspond to a command of 8 bits). Since there is no margin in the processing capacity of the CPU of the main board 1, a simple one that does not place an excessive processing burden and does not require a large amount of ROM capacity is desired. This is because a simple encryption algorithm can be processed relatively easily by the CPU. This point is important for implementation.

  In the conventional unauthorized apparatus, a list of commands is prepared in advance and stored in a ROM or the like, and then sent out as appropriate. On the other hand, if the command system is often changed by encryption as in the embodiment of the present invention, illegal acts can be sufficiently prevented. If the encryption algorithm is changed when the model of the gaming machine is updated, the fraudulent person cannot give up because the fraudster cannot follow the change of the code system.

Embodiment 2 of the Invention
FIG. 7 is a block diagram showing an electrical schematic structure of the gaming machine according to the second embodiment of the invention. In this figure, the same or corresponding parts as those in the first embodiment of the invention are denoted by the same reference numerals. The gaming machine includes a main substrate 1 (first control device) and a sub-substrate 2 (second control device) that operates in response to a command from the main processing device.

  7 includes an activation unit 3a, a key (delay period) generation unit 3b, and a command encryption processing unit 3c in the main board 1, and a key (delay period) management unit 4a and a command decryption process in the sub-board 2. Part 4b is included. In contrast, the gaming machine of FIG. 1 described above includes these parts separately from the main board 1 and the sub board 2. Whether the encryption process and the decryption process are performed inside the main board 1 and the sub board 2 or outside is not the essence of the present invention, and any configuration can be arbitrarily employed.

  7 is the same as that shown in FIG. 2, but the key (delay period) generation unit 3b, command encryption processing unit 3c, key (delay period) management unit 4a, and command decryption processing unit 4b , Different from that shown in FIG. Hereinafter, these will be described.

  The key (delay period) generation unit 3b generates a delay period when performing encryption processing and decryption processing. A correct command can be obtained by performing the decryption process using the same delay period as the encryption process, but a correct command cannot be obtained when the delay periods of the encryption process and the decryption process do not match. Therefore, it can be said that the delay period performs the same function as the encryption key. Note that the key may be predetermined, that is, the same delay period may always be used. Even in this case, a certain effect is obtained.

  Block diagrams of the command encryption processing unit 3c and the command decryption processing unit 4b are shown in FIGS. Similarly, a flowchart is shown in FIG.

  In FIG. 8, reference numerals 131 and 141 denote delay means for delaying data for a predetermined period. The delay unit 131 delays transmission data, that is, an encryption command, and the delay unit 141 delays reception data, that is, an encryption command. The delay means is composed of, for example, one or a plurality of registers, a memory and the like. The delay period can be adjusted by changing the number of registers or the clock, or changing the memory read timing or clock. The key is used at this time. An arithmetic unit 132 adds the output of the delay unit 131 to the command received from the main board 1, and an arithmetic unit 142 subtracts the output of the delay unit 141 from the received encrypted command. The output of the computing unit 132 is an encrypted command, and the output of the computing unit 142 is a decrypted command. Note that addition and subtraction may be interchanged, and may be subtracted during the encryption process and added during the decryption process.

When the command is Xn, the encryption command is Yn, and the decryption result is An (n = 0, 1, 2,...), The output of the command encryption processing unit 3c and the output of the command decryption processing unit 4b are as follows. become.
Yn = Xn + Yn−k
An = Yn−Yn−k
The subscripts n and nk indicate the time (data order) (k: any natural number). nk means k-th previous data (delayed data) compared to n. Here, k corresponds to a delay period.

  As can be easily understood by comparing the above two expressions, An = Xn. Therefore, the command of the main board 1 can be correctly transmitted to the sub board 2. On the other hand, since what is observed between the main board 1 and the sub-board 2 (the position of the unauthorized device X) is the encryption command Yn, it is difficult to perform an unauthorized act.

  If k does not match in both encryption processing and decryption processing, a correct command cannot be obtained. An unauthorized person who does not know k cannot send an unauthorized command. In this sense, k serves as a key. As shown in FIG. 10 described later, the key k is transmitted from the main board to the sub board prior to communication.

  When transmitting the key k, the output Yn of the calculator 132 may be transmitted, or the command before encryption (input Xn of the calculator 132) may be transmitted. In the former case, the key k needs to be matched in advance between the main board and the sub board, but it is preferable from the viewpoint of preventing fraud. In the latter case, it is not necessary to match the key k.

  A storage unit (memory) can be used instead of the delay units 131 and 141 shown in FIG. The storage unit on the main board side stores the output Yn of the computing unit 132, and the storage unit on the sub board side stores reception data (encryption command) Yn. If the data of the storage unit used on the main board side and the sub board side is promised in advance, the same operational effects as in the case of the delay means can be obtained. The promise (for example, the address of the memory, the minimum data, the maximum data, the intermediate value, etc.) corresponds to the key (delay time).

  When a storage unit (memory) is used instead of the delay means 131, the key is typically an address indicating specific data in the storage unit, not the delay k. If the data in the storage unit on the main board side and the storage part on the sub board are matched, the key can be used as a common address. The key can also be updated at an appropriate timing as described above. The data in the storage unit may be updated sequentially or may be fixed. If a first-in first-out (FIFO) memory is used as the storage unit, it operates in the same manner as the delay means.

The output of the command encryption processing unit 3c and the output of the command decryption processing unit 4b when the storage unit is used are typically as follows.
Yn = Xn + Yk
An = Yn−Yk
Here, k is the address of the storage unit.

  In the case of the above two formulas, An = Xn. Therefore, the command of the main board 1 can be correctly transmitted to the sub board 2. On the other hand, since what is observed between the main board 1 and the sub-board 2 (the position of the unauthorized device X) is the encryption command Yn, it is difficult to perform an unauthorized act.

  The processing procedure will be described with reference to FIG.

1. Encryption process S50: A command (Xn) to be transmitted is received from the main board.
S51: Read transmission data (Yn-k) of the previous time or k times before. Transmission data (encrypted command) is stored in a memory or the like. When a storage unit is used instead of the delay unit, the contents of the storage unit at the address specified by the key are read.
S52: The transmission data read in the previous step is added to the command. Or you may make it subtract.
S53: The addition result or subtraction result Yn (encryption command) of the previous step is transmitted.
S54: The transmitted data Yn is stored. The data stored here is used in S51 as the previous or k-th previous transmission data. When a storage unit is used in place of the delay means, the data may be constantly updated in this way, or a random number used for encryption processing is exchanged at the time of key exchange in FIG. And may be used.

2. Decoding process S60: Receive transmission data Yn from the main board.
S61: Read transmission data (Yn-k) of the previous time or k times before. Transmission data (encrypted command) is stored in a memory or the like. When a storage unit is used instead of the delay unit, the contents of the storage unit at the address specified by the key are read.
S62: The transmission data read in the previous step is subtracted from the transmission data. When subtracted in S52, addition is performed.
S63: The subtraction result or the addition result An of the previous step is passed to the sub-board as a command.
S64: The received data Yn is stored. The data stored here is used in S61 as the previous or k-th previous transmission data. When the storage unit is used instead of the delay means, the data may be constantly updated as in the main board side, or a random number used for encryption processing may be exchanged when exchanging keys in FIG. May be used continuously for a certain period.

  FIG. 10 is a flowchart showing a procedure for generating an encryption key. The process of FIG. 10 is started by turning on the gaming machine or starting the game. This process is the same as in FIG. 3, except that a delay period is generated as a key.

The activation unit 3a determines whether it is time to newly generate or change a cryptographic key, and the conditions for extracting the cryptographic key are (a) when the power is turned on, (b) a predetermined timing for each game, for example, the first When a reel index is detected, a delay period is generated. For example, a random number is acquired and the random number itself or a value obtained from the random number (using some bits or performing an operation between bits) is set as the delay period.
The command encryption / decryption procedure is the same as in the first embodiment.

  When a storage unit is used instead of the delay unit, the address of the storage unit is sent as a key. At this time, random numbers used for encryption / decryption processing may be transmitted together.

  In the key transmission in S12, the calculation result Yn output from the calculation unit 132 in FIG. 8 may be transmitted as a key, or the command Xn output from the main board 1 may be transmitted as a key. In the latter case, the sub board 1 directly receives the command Xn and uses it as a key.

  According to the second embodiment of the present invention, when transmitting a command to the sub-board, the previous transmission data is stored, added to the command to be transmitted, and then transmitted to the sub-board. Thereafter, similarly, the transmitted data is added to the command to be transmitted. On the other hand, on the sub-board side, command data is obtained by subtracting the previously received data from the received data. By performing such processing, it becomes difficult to know what command is sent between the main board and the sub-board, and thus it is possible to prevent fraud. The second embodiment of the invention can be realized while suppressing the increase in the capacity of the main program as much as possible.

  In the above description, a slot machine is taken as an example of a gaming machine, but the present invention is not limited to this. Needless to say, the present invention can also be applied to a gaming machine having two or more processing substrates, and an unauthorized device may be placed between them, such as a pachinko machine.

  The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

It is a front view of a gaming machine (slot machine). 1 is a block diagram of a gaming machine according to a first embodiment of the invention. It is a block diagram which shows the production | generation procedure of the encryption key which concerns on Embodiment 1 of invention. It is a block diagram which shows the encryption / decryption procedure of the command which concerns on Embodiment 1 of invention. It is a flowchart which shows the outline | summary of operation | movement of a gaming machine. It is a block diagram of the conventional gaming machine. It is a block diagram of the gaming machine according to the second embodiment of the invention. It is a block diagram of the command encryption process part and command decryption process part which concern on Embodiment 2 of invention. It is a flowchart of the command encryption process and command decryption process which concern on Embodiment 2 of invention. It is a block diagram which shows the production | generation procedure of the encryption key which concerns on Embodiment 2 of invention.

Explanation of symbols

10 Slot Machine 11 Housing 12 Display Window 13 Symbol Display Window 16 Bet Switch 17 Checkout Switch 20 Random Number Generator 30 Start Switch 31 Connector 32 Processing / Display Unit 33 Connector 40 Rotating Reel 42 Reel Tape 50 Stop Switch 60 Reel Unit 61 Symbol 62 Liquid crystal display unit 70 Reel drive unit 71 Reel position detection circuit 80 Hopper drive unit 81 Hopper 82 Medal detection unit 100 Medal insertion slot 131, 141 Delay means 132, 142 Calculator 200 Liquid crystal control board 201 Speaker board 202 LED board 304 Medal payout slot 311 Medal receiving part (bottom plate)

Claims (16)

In response to the player's operation, the internal lottery and winning determination are performed, and a first processing unit that controls payout of game media in accordance with the winning, and a command from the first processing unit that notifies the result of the internal lottery. In a gaming machine comprising a second processing unit that performs an effect including
An encryption unit including a key generation unit that generates an encryption key and outputs the key, and a command encryption processing unit that receives a command from the first processing unit and encrypts and outputs the command based on the encryption key When,
A key management unit for storing a cryptographic key received from the key generation unit, a command encrypted from the command encryption processing unit, and decrypting the encrypted command based on the stored cryptographic key; A gaming machine comprising: a decoding unit including a command decoding processing unit to be sent to the second processing unit. A first processing unit for performing internal lottery and winning determination in response to a player's operation, and for controlling payout of game media in accordance with winning, a key generating unit for generating a cryptographic key and outputting the key; and A first control device comprising: a command encryption processing unit that receives a command from the first processing unit and encrypts and outputs the command based on the encryption key;
A second processing unit that receives a command from the first processing unit and produces an effect including notification of an internal lottery result; a key management unit that stores a cryptographic key received from the key generation unit; and the command encryption process A second control device comprising: a decryption unit including a command decryption processing unit that receives the encrypted command from the unit, decrypts the encrypted command based on the stored encryption key, and sends the encrypted command to the second processing unit And
A gaming machine, wherein the encryption key is connected to be able to transmit from the first control device to the second control device.   The encryption unit includes an activation unit that activates encryption key generation and transmission processing, and the activation unit activates the key generation unit at any timing when the power is turned on or for each game. The gaming machine according to claim 1 or claim 2.   The encryption key specifies a bit shift amount, the command encryption processing unit rotates the command according to the encryption key, and the command decryption processing unit performs encryption according to the encryption key. 3. The gaming machine according to claim 1, wherein rotation is performed in the reverse direction with respect to the command that has been issued.   The command encryption processing unit obtains an exclusive OR of the encryption key and the command, and the command decryption processing unit obtains an exclusive OR of the encryption key and the encrypted command. The gaming machine according to claim 1 or claim 2. The command encryption processing unit includes a delay unit that delays an encrypted output for a specified period, and a calculation unit that adds or subtracts the output of the delay unit to the command received from the first processing unit and outputs a calculation result; Including
The encryption key specifies a delay period in the delay means;
The command decryption processing unit is configured to delay the received encrypted command for a period corresponding to the encryption key, and to subtract or add the output of the delay means to the received encrypted command to obtain a calculation result The game machine according to claim 1, further comprising: an arithmetic unit that outputs. The command encryption processing unit stores an encrypted output generated in accordance with the progress of the game and outputs the stored encrypted output according to a designation, and outputs the first storage unit to the first process. A first arithmetic unit that performs an operation including addition or subtraction on the command received from the unit and outputs the operation result;
The command decryption processing unit stores the received encrypted output and outputs the stored encrypted output in accordance with the designation, and subtracts the output of the second storage unit from the received encrypted output Or a second operation unit that performs an inverse operation including addition and outputs an operation result,
The first storage unit outputs an encrypted output stored according to the key of the key generation unit,
The gaming machine according to claim 1 or 2, wherein the second storage unit outputs an encrypted output stored in accordance with a key of the key management unit.   8. The gaming machine according to claim 7, wherein the encryption key is a calculation result output from the first calculation unit or a command output from the first processing unit. In response to the player's operation, the internal lottery and winning determination are performed, and a first processing unit that controls payout of game media in accordance with the winning, and a command from the first processing unit that notifies the result of the internal lottery. In a gaming machine comprising a second processing unit that performs an effect including
A delay unit that delays the encrypted output for a predetermined period; and the command is encrypted and output by adding or subtracting the output of the delay unit to the command received from the first processing unit. An encryption unit including an arithmetic unit that supplies the output to the delay unit,
Delay means for delaying the encrypted command received from the encryption unit for a predetermined period; and the encrypted command by subtracting or adding the output of the delay means to the received encrypted command. A gaming machine comprising: a command decoding unit that decodes and sends the command to the second processing unit. A first processing unit for performing internal lottery and winning determination in response to a player's operation, and performing payout control of game media in accordance with the winning; delay means for delaying the encrypted output for a predetermined period; An encryption unit including an arithmetic unit that encrypts and outputs the command by adding or subtracting the output of the delay unit to the command received from the first processing unit and supplies the encrypted output to the delay unit A first control device comprising:
A second processing unit that receives a command from the first processing unit and produces an effect including notification of an internal lottery result; a delay unit that delays an encrypted command received from the encryption unit; A second control device comprising: a command decryption unit that decrypts the encrypted command by subtracting or adding the output of the delay means to the received encrypted command and sends the command to the second processing unit; Prepared,
A gaming machine, wherein the encrypted command is connected so as to be transmitted from the first control device to the second control device. In response to the player's operation, the internal lottery and winning determination are performed, and a first processing unit that controls payout of game media in accordance with the winning, and a command from the first processing unit that notifies the result of the internal lottery. In a gaming machine including a second processing unit that performs an effect including, a command communication method from the first processing unit to the second processing unit,
A key generation processing step for generating a cryptographic key and outputting the key when a predetermined condition occurs; and
A command encryption processing step for receiving a command from the first processing unit and encrypting and outputting the command based on the encryption key;
A key update processing step for storing the received encryption key;
A command communication method in a gaming machine, comprising: a command decryption processing step of receiving an encrypted command and decrypting the encrypted command based on a stored encryption key. Determining whether the command was decoded correctly;
12. The command communication method in the gaming machine according to claim 11, further comprising a step of discarding the command when the command is not correctly decoded. In response to the player's operation, the internal lottery and winning determination are performed, and a first processing unit that controls payout of game media in accordance with the winning, and a command from the first processing unit that notifies the result of the internal lottery. In a gaming machine including a second processing unit that performs an effect including, a command communication method from the first processing unit to the second processing unit,
Storing an encrypted command transmitted from the first processing unit to the second processing unit;
Adding or subtracting the transmitted encrypted command to the command received from the first processing unit, encrypting the command, and transmitting to the second processing unit;
Storing the received encrypted command;
A command communication method in a gaming machine comprising: a step of decrypting a received encrypted command by subtracting or adding the received encrypted command. In response to the player's operation, the internal lottery and winning determination are performed, and a first processing unit that controls payout of game media in accordance with the winning, and a command from the first processing unit that notifies the result of the internal lottery. A command communication program from the first processing unit to the second processing unit in a gaming machine including a second processing unit that performs an effect including:
A key generation processing step for generating a cryptographic key and outputting the key when a predetermined condition occurs; and
A command communication program comprising: a command encryption processing step that receives a command from the first processing unit and encrypts and outputs the command based on the generated encryption key. In response to the player's operation, the internal lottery and winning determination are performed, and a first processing unit that controls payout of game media in accordance with the winning, and a command from the first processing unit that notifies the result of the internal lottery. A command communication program from the first processing unit to the second processing unit in a gaming machine including a second processing unit that performs an effect including:
A key update processing step for storing the received encryption key;
A command communication program comprising: a command decryption processing step for receiving an encrypted command and decrypting the encrypted command based on a stored encryption key. further,
Determining whether the command was decoded correctly;
The command communication program according to claim 15, further comprising: discarding the command when the command is not correctly decoded.

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