COMMUNICATION METHOD, COMMUNICATION PROGRAM, AND AUTOMATED TELLER MACHINE

Abstract

A communication method according to an embodiment of the present invention includes: performance of authentication by a first unit, which is installed outside of a housing container of an automated teller machine, and a second unit, which is installed inside of the housing container, through data communication that is encrypted using a first encryption scheme; and, if authentication is successful, transmission by the first unit of an instruction to the second unit through data communication that is encrypted using a second encryption scheme.

Description

[Technical field]

[0001] An embodiment of the present invention relates to a communication method, a communication program, and an automated teller machine. [Background technology]

[0002] Conventionally, an automatic teller machine (ATM) used in transactions at financial institutions and the like is composed of multiple units, such as a bill transport unit that transports bills when depositing or withdrawing money, and a bill recycling unit (BRU) that stores the bills transported by the bill transport unit and dispenses the bills via the bill transport unit based on a withdrawal instruction. Regarding communication between units in this automatic teller machine, a conventional technology is known that prevents unauthorized operations such as dispensing using unauthorized commands by transmitting commands such as withdrawals using encrypted communication. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-049770 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional technology has a problem in that if the encrypted communication for issuing a command such as a withdrawal is deciphered by hacking or the like, it is difficult to prevent fraudulent operations such as withdrawals using fraudulent commands.

[0005] In one aspect, an object of the present invention is to provide a communication method, a communication program, and an automated teller machine that can prevent unauthorized operations in an automated teller machine. [Means for solving the problem]

[0006] In one aspect, a communication method includes a first unit installed outside a storage facility of an automated teller machine and a second unit installed inside the storage facility performing authentication using data communication encrypted using a first encryption method, and if the authentication is successful, the first unit transmits instructions to the second unit using data communication encrypted using a second encryption method. Effect of the Invention

[0007] It is possible to prevent fraudulent operation of automated teller machines. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram illustrating an example of the configuration of an automated teller machine according to an embodiment. [Diagram 2] FIG. 2 is a flowchart illustrating an operation example of the automated teller machine according to the embodiment. [Diagram 3] FIG. 3 is a flowchart illustrating an operation example of the automated teller machine according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram illustrating an overview of communication between control units. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a communication method, a communication program, and an automated teller machine according to the embodiments will be described with reference to the drawings. Components having the same functions in the embodiments will be given the same reference numerals, and duplicated descriptions will be omitted. Note that the communication method, the communication program, and the automated teller machine described in the following embodiments are merely examples, and do not limit the embodiments. In addition, the following embodiments may be appropriately combined within a range that does not cause contradiction.

[0010] 1 is a block diagram showing an example of the configuration of an automated teller machine according to an embodiment of the present invention. As shown in FIG. 1, the automated teller machine 1 includes a banknote transport unit 2, a safe 3, and an ATM control unit 4.

[0011] The banknote transport unit 2 processes the deposit and withdrawal of banknotes in response to a user's banknote deposit and withdrawal transaction operations. The safe 3 is a storage unit that is detachably attached to the banknote transport unit 2 and is capable of storing banknotes and the like. The ATM control unit 4 controls various processes in the automated teller machine 1.

[0012] The banknote transport unit 2 has a deposit port 11 , a withdrawal port 12 , a discrimination section 13 , a transport path 14 , a banknote transport unit control section 15 , and a passage sensor 16 .

[0013] The deposit port 11 is an insertion port for banknotes when depositing banknotes into the banknote transport unit 2. The withdrawal port 12 is an outlet for withdrawing banknotes when withdrawing banknotes from the banknote transport unit 2. The discrimination unit 13 has, for example, a sensor that discriminates the type of banknote passing on the transport path 14, and notifies the banknote transport unit control unit 15 of the discrimination result.

[0014] The transport path 14 is a transport path along which banknotes are transported in a banknote deposit / withdrawal process. The transport path 14 includes, for example, a transport path along which banknotes are transported from the deposit port 11 to the safe 3, and a transport path along which banknotes are transported from the safe 3 to the withdrawal port 12. In the transport path 14, a mechanical drive unit (not shown) such as a transport roller and a transport motor is driven under the control of the banknote transport unit control unit 15 to transport banknotes from the deposit port 11 to the safe 3, or transport banknotes from the safe 3 to the withdrawal port 12.

[0015] The banknote transport unit control unit 15 controls the operation of the banknote transport unit 2 based on instructions from the ATM control unit 4. The banknote transport unit control unit 15 includes, for example, a CPU 151 (Central Processing Unit), a memory 152, and an FPGA 153 (Field Programmable Gate Array).

[0016] The CPU 151 is a processing unit that performs general-purpose processing related to the operation of the banknote transport unit 2 by expanding the program stored in the memory 152 into an internal memory and executing it. For example, under the control of the ATM control unit 4, the CPU 151 transmits a drive signal to a mechanical drive unit to control the operation of the banknote transport unit 2. Also, under the control of the ATM control unit 4, the CPU 151 communicates with a unit in the safe 3 (the banknote reuse unit 21 in the illustrated example) (details will be described later).

[0017] The memory 152 is, for example, a non-volatile memory, etc. The memory 152 stores programs related to the arithmetic processing of the CPU 151, setting information unique to the banknote transport unit 2 (for example, unique information such as a serial number related to the CPU 151), key information (for example, a private key, a public key) used for communication between units, etc.

[0018] The FPGA 153 is a processing unit that performs specific processes (e.g., encryption and decryption of data) in the banknote transport unit 2 under the control of the CPU 151. This FPGA 153 is not limited to an FPGA, and may be implemented by a PLD (Programmable Logic Device) of that kind, such as an ASIC (Application Specific Integrated Circuit) or a CPLD (Complex Programmable Logic Device).

[0019] The safe 3 is an example of a storage unit, and has, for example, an opening and closing door (not shown) on the front of the housing that can be locked with an electronic lock or the like, and inside has a bill reuse unit 21. For this reason, only users who can unlock the opening and closing door of the safe 3 (for example, managers who manage and maintain the automated teller machine 1) can access the inside of the safe 3, and access to units installed inside the safe 3 (the bill reuse unit 21 in this embodiment) is restricted.

[0020] The banknote reuse unit 21 has a plurality of recycle vaults 22, a rejected vault 23, a transport path 24, a cassette control unit 25, and an operation detection unit 26. The recycle vault 22 is a storage unit that stores transported banknotes, for example, by banknote type. The rejected vault 23 is a storage unit that stores rejected notes among the transported banknotes.

[0021] The transport path 24 is a transport path for transporting banknotes within the banknote reuse unit 21. The transport path 24 includes, for example, a transport path for transporting banknotes from the banknote transport unit 2 to the recycle vault 22 or the rejected vault 23, and a transport path for transporting banknotes from the rejected vault 23 to the banknote transport unit 2. In the transport path 24, a mechanical drive unit (not shown) such as a transport roller and a transport motor is driven under the control of the cassette control unit 25 to transport banknotes from the banknote transport unit 2 to the recycle vault 22 or the rejected vault 23, or transport banknotes from the rejected vault 23 to the banknote transport unit 2.

[0022] The cassette control unit 25 controls the operation of the banknote reuse unit 21 based on instructions from the ATM control unit 4 notified via the banknote transport unit control unit 15. The cassette control unit 25 includes a CPU 251, a memory 252, and an FPGA 253, for example.

[0023] The CPU 251 is a processing unit that performs general-purpose processing related to the operation of the banknote reuse unit 21 by expanding the program stored in the memory 252 into an internal memory and executing it. For example, the CPU 251 transmits a drive signal to a mechanical drive unit based on an instruction from the ATM control unit 4, and controls the operation of the banknote reuse unit 21. The CPU 251 also communicates with the banknote transport unit control unit 15 (details will be described later).

[0024] The memory 252 is, for example, a non-volatile memory, etc. The memory 252 stores programs related to the arithmetic processing of the CPU 251, key information (for example, a private key, a public key) used for communication between units, and the like.

[0025] The FPGA 253 is a processing unit that performs specific processes (e.g., encryption and decryption of data) in the banknote reuse unit 21 under the control of the CPU 251. This FPGA 253 is not limited to an FPGA, and may be implemented by a PLD of that kind, such as an ASIC or a CPLD.

[0026] The operation detection unit 26 is a switch, a sensor, or the like installed in the safe 3. The operation detection unit 26 detects physical operations by the user in the safe 3. Examples of physical operations include operations to pull out multiple recycle cabinets 22 and reject cabinets 23, and operations to press specific switches. The operation detection unit 26 notifies the cassette control unit 25 of the detection results of these physical operations.

[0027] The ATM control unit 4 includes, for example, a CPU 41 and a memory 42. The CPU 41 is a processing unit that performs general-purpose processing related to the operation of the automated teller machine 1 by expanding a program stored in the memory 42 into an internal memory and executing it. For example, under the control of the ATM control unit 4, the CPU 151 transmits a drive signal to a mechanical drive unit and controls the operation of the banknote transport unit 2. Also, under the control of the ATM control unit 4, the CPU 151 communicates with a unit in the safe 3 (the banknote reuse unit 21 in the illustrated example) (details will be described later).

[0028] The memory 42 is, for example, a non-volatile memory, etc. The memory 42 stores programs related to the arithmetic processing of the CPU 41, setting information unique to the ATM control unit 4 (control unit specific information such as HDID), key information (for example, a private key, a public key) used for communication between units, etc.

[0029] Next, operations relating to communication between units in the automated teller machine 1 will be described in detail with reference to Figures 2 and 3. Figures 2 and 3 are flowcharts showing an example of the operation of the automated teller machine according to the embodiment.

[0030] Specifically, Fig. 2 is a flowchart showing an example of an operation when performing initial settings regarding communication between units when replacing a unit, etc. Fig. 3 is a flowchart showing an example of an operation when performing communication between units at normal startup.

[0031] First, the operation for performing the initial setting for the communication between the units will be described. As shown in Fig. 2, when replacing a unit, etc., the initial setting process is started in the ATM control unit 4, the banknote transport unit control unit 15, and the cassette control unit 25 by powering on (S1) with a button operation for instructing the initial setting.

[0032] When the initial setting process is started, the CPU 41 of the ATM control unit 4 generates an RSA public key (A) and a private key in the well-known RSA encryption method. Next, the CPU 41 reads out an HDID unique to the CPU 41 stored in the memory 42 or the like (S2). This HDID is information that is transmitted to the banknote transport unit control unit 15 together with the RSA public key (A) as control unit unique information in the ATM control unit 4.

[0033] Next, the CPU 41 of the ATM control unit 4 issues an initial common encryption key generation command instructing settings for communication between the banknote transport unit control unit 15 and the cassette control unit 25 (S3). Next, the CPU 41 of the ATM control unit 4 transmits the issued initial common encryption key generation command together with the RSA public key (A) and the HDID to the banknote transport unit control unit 15 (S4).

[0034] The CPU 151 of the banknote transport unit control unit 15 that has received the initial common encryption key generation command generates an RSA public key (B) and a private key in the well-known RSA encryption method. Next, the CPU 151 reads out CPU specific information (e.g., MAC address) stored in the memory 152 or the like (S5). This CPU specific information is information that is transmitted to the cassette control unit 25 together with the RSA public key (B) as specific information in the banknote transport unit control unit 15.

[0035] Next, the CPU 151 of the banknote transport unit control unit 15 issues an initial common encryption key generation command (S6) and transmits the issued initial common encryption key generation command, together with the RSA public key (B) and the CPU-specific information, to the cassette control unit 25 (S7).

[0036] The CPU 251 of the cassette control unit 25 that has received the initial common encryption key generation command creates an initial encryption key (B) and encrypts the created initial encryption key (B) with the RSA public key (B) (S8). This initial encryption key (B) is, for example, a random number generated by the CPU 251 using a value detected by a sensor or the like of the operation detection unit 26 as a seed value.

[0037] Next, the CPU 251 of the cassette control unit 25 checks whether or not a specific physical intervention process has occurred in the safe 3 (for example, an operation to insert or remove a cassette in the recycle box 22, the reject box 23, etc.) based on the detection result of the operation detection unit 26 (S9).

[0038] When the CPU 251 of the cassette control unit 25 is able to confirm the specific physical intervention process, it stores the CPU unique information and the initial encryption key (B) notified by the banknote transport unit control unit 15 in the memory 252. The CPU 251 may store the CPU unique information notified by the banknote transport unit control unit 15 directly in the memory 252 without confirming the presence or absence of the specific physical intervention process. In this embodiment, when a specific physical intervention process in the safe 3, that is, an operation in the safe 3 by a user who can unlock the door of the safe 3, is detected, it is determined that a legitimate setting process is being performed, and the CPU unique information is stored in the memory 252, thereby making it possible to prevent unauthorized setting registration from being performed.

[0039] Next, the cassette control unit 25 CPU 251 transmits the initial encryption key (B) encrypted with the RSA public key (B) to the banknote transport unit control unit 15 (S10). The CPU 151 of the banknote transport unit control unit 15 that has received the encrypted initial encryption key (B) decrypts it with the private key (B) to obtain the initial encryption key (B) (S11) and stores it in the memory 152.

[0040] Next, the CPU 151 of the banknote transport unit control unit 15 creates an initial encryption key (A) and encrypts the created initial encryption key (B) with the RSA public key (A) (S12). This initial encryption key (A), like the initial encryption key (A), is, for example, a random number generated by the CPU 151 using a value detected by a sensor or the like as a seed value.

[0041] Next, the CPU 151 of the banknote transport unit control unit 15 transmits the initial encryption key (A) encrypted with the RSA public key (A) to the ATM control unit 4 (S13). The CPU 41 of the ATM control unit 4 that has received the encrypted initial encryption key (A) decrypts it with the private key (A) to obtain the initial encryption key (A) (S14) and stores it in the memory 42.

[0042] Next, the operation when communicating between the units after the above-mentioned initial setting will be described. As shown in Fig. 3, when the power is turned on normally (S21), the ATM control unit 4, the banknote transport unit control unit 15, and the cassette control unit 25 start processing.

[0043] After the power is turned on (S21), the CPU 151 of the banknote transport unit control unit 15 and the CPU 251 of the cassette control unit 25 perform authentication through data communication using a general-purpose encryption method such as DES (Data Encryption Standard) or AES (Advanced Encryption Standard) (S22 to S25).

[0044] Specifically, the CPU 151 of the banknote transport unit control section 15 reads out CPU specific information stored in the memory 152 or the like, and generates an authentication command in which this CPU specific information is set. Next, the CPU 151 encrypts the generated authentication command with a set encryption key (B) (S22). This encryption is performed by a preset encryption method in a general-purpose encryption method such as DES or AES.

[0045] As a result, the CPU 151 issues encrypted data for the authentication command in which the CPU unique information is set. Next, the CPU 151 of the banknote transport unit control unit 15 transmits the authentication command (encrypted message) to the cassette control unit 25 (S23).

[0046] The CPU 251 of the cassette control unit 25 that has received the authentication command (encrypted message) decrypts the encrypted message with the set encryption key (B). This decryption is performed by a preset encryption method among general-purpose encryption methods such as DES, AES, etc., just like the banknote transport unit control unit 15.

[0047] Next, CPU 251 compares the CPU unique information contained in the authentication command obtained by decryption with the CPU unique information stored in memory 252 by default, and checks whether the two pieces of information match (S24).

[0048] If the CPU specific information included in the authentication command matches the CPU specific information at the time of initial setting, the CPU 251 authenticates the communication as normal and enables the FPGA 253. That is, when the cassette control unit 25 authenticates the communication as normal, encryption and decryption of data using the FPGA 253 becomes valid.

[0049] Furthermore, if the CPU specific information included in the authentication command does not match the CPU specific information at the time of initial setting and the communication is not authenticated as normal, the CPU 251 does not enable the FPGA 253. As a result, when the cassette control unit 25 does not authenticate the communication as normal, the encryption and decryption of data using the FPGA 253 becomes invalid.

[0050] Furthermore, if the communication is not authenticated as normal, the CPU 251 erases (flushes) the CPU specific information stored in the memory 252 during initial configuration. This makes it possible to prevent unauthorized attempts to authenticate by arbitrarily setting CPU specific information from succeeding.

[0051] Next, the CPU 251 notifies the banknote transport unit control section 15 of the authentication result (S25). If the notified authentication result is that the communication is normal, the CPU 151 of the banknote transport unit control section 15 enables the FPGA 153, as in the cassette control section 25. As a result, if the banknote transport unit control section 15 also authenticates the communication as normal, encryption and decryption of data using the FPGA 153 becomes effective.

[0052] Moreover, if the authentication result does not authenticate the normal communication, the CPU 151 does not enable the FPGA 153. As a result, in the banknote transport unit control unit 15 as well, if the authentication does not authenticate the normal communication, the encryption and decryption of data using the FPGA 153 is invalidated.

[0053] Next, the CPU 251 of the cassette control unit 25 and the CPU 151 of the banknote transport unit control unit 15 update each other's encryption key (B) to the new encryption key (S26, S27).

[0054] After the communication has been authenticated as normal by the above authentication, instructions from the banknote transport unit control unit 15 to the cassette control unit 25 (for example, a withdrawal transaction command to withdraw banknotes) are sent via data communication encrypted using an encryption method different from that used at the time of authentication, using the FPGAs 153, 253 that were enabled at the time of authentication (S28 to S33).

[0055] Specifically, the CPU 41 of the ATM control unit 4 encrypts a command for performing mechanical operations related to the banknote transport unit 2 and the banknote reuse unit 21 with the encryption key (A) already stored in the memory 42 (S28). This encryption is performed by a preset encryption method among general-purpose encryption methods such as DES, AES, etc.

[0056] For example, the CPU 41 of the ATM control unit 4 issues a withdrawal transaction command to withdraw banknotes from the withdrawal port 12, and encrypts the issued withdrawal transaction command with the encryption key (A) (S29). Next, the CPU 41 of the ATM control unit 4 transmits the withdrawal transaction command (encrypted message) to the banknote transport unit control unit 15 (S30).

[0057] The CPU 151 of the banknote transport unit control unit 15 that has received the withdrawal transaction command (encrypted message) decrypts the encrypted message with the set encryption key (A). This decryption is performed by a preset encryption method among general-purpose encryption methods such as DES, AES, etc., just like the ATM control unit 4.

[0058] If there is no problem with the decoding of the withdrawal transaction command, the CPU 151 of the banknote transport unit control section 15 executes a withdrawal control process based on the withdrawal transaction command (S31, S35). Specifically, the CPU 151 sends a drive signal to the mechanical drive section based on the withdrawal transaction command, thereby dispensing the banknotes transported by the banknote reuse unit 21 from the withdrawal port 12 via the transport path 14.

[0059] Next, the CPU 151 of the banknote transport unit control unit 15 encrypts the withdrawal transaction command using a unique encryption method using the FPGA 153, which has been validated as a result of authenticating normal communication, and transmits the encrypted data to the cassette control unit 25 (S32).

[0060] The unique encryption method in the FPGA 153 may be any encryption method that is different from that used during authentication. For example, the unique encryption method may be an encryption technique that generates random numbers using data in the automated teller machine 1 (such as time information or device-specific information), an encryption technique that shares an encryption key and simultaneously updates the encryption key used, or an encryption technique that periodically changes the order in which communication data is sent.

[0061] The CPU 251 of the cassette control unit 25 receives the data encrypted using a unique encryption method and uses the FPGA 253, which has been validated as a result of authenticating the communication, to restore (decrypt) the data using the unique encryption method (S33).

[0062] If there is no problem with the data restoration, the CPU 251 of the cassette control unit 25 executes a withdrawal control process based on the restored withdrawal transaction command (S34). Specifically, the CPU 251 transmits a drive signal to the mechanical drive unit based on the withdrawal transaction command, thereby transporting the banknotes stored in the rejected vault 23 to the banknote transport unit 2 via the transport path 24.

[0063] Next, the CPU 151 of the banknote transport unit control unit 15 ends the withdrawal control process upon completion of dispensing of the banknotes to the withdrawal port 12 in response to the withdrawal transaction command (S36), and transmits a withdrawal result indicating completion of dispensing to the ATM control unit 4 (S37).

[0064] Next, the CPU 41 of the ATM control unit 4 and the CPU 151 of the banknote transport unit control unit 15 update each other's encryption key (A) to the new encryption key (S38, S39), and end the process corresponding to the command.

[0065] As described above, the ATM machine 1 performs authentication by data communication encrypted by the first encryption method between the banknote transport unit 2 installed outside the safe 3 of the ATM machine 1 and the banknote reuse unit 21 installed inside the safe 3. Furthermore, in the ATM machine 1, if authentication is performed normally, the banknote transport unit 2 transmits instructions to the banknote reuse unit 21 by data communication encrypted by the second encryption method.

[0066] Fig. 4 is an explanatory diagram for explaining an overview of communication between control units. As shown in Fig. 4, in the automated teller machine 1, when the banknote transport unit 2 and the banknote reuse unit 21 installed in the safe 3 communicate with each other in response to an instruction C1 (e.g., a withdrawal transaction command) from the ATM control unit 4, first, authentication is performed by encrypting an authentication command C2 with a general-purpose encryption method (first encryption method). If this authentication is performed normally, the automated teller machine 1 encrypts data communication C3 (e.g., a withdrawal transaction command) with an encryption method (second encryption method) different from that used for authentication, using the FPGAs 153 and 235 of the banknote transport unit control unit 15 and the cassette control unit 25.

[0067] In this way, in the automated teller machine 1, by performing authentication through data communication using the first encryption method, which is different from the second encryption method, it is possible to prevent fraudulent operations such as dispensing using unauthorized commands, even in cases where communication using the second encryption method is deciphered by hacking or the like.

[0068] Furthermore, in the automated teller machine 1, the banknote transport unit 2 encrypts the set identification information using a first encryption method and notifies the banknote reuse unit 21, and the banknote reuse unit 21 stores the notified identification information in the memory 252. During authentication, the automated teller machine 1 notifies the banknote reuse unit 21 of the identification information from the banknote transport unit 2 through data communication, and the banknote reuse unit 21 compares the notified identification information with the identification information stored in the memory 252. This allows the automated teller machine 1 to perform authentication using the identification information of the banknote transport unit 2 that is stored in advance in the memory 252 of the banknote reuse unit 21.

[0069] Furthermore, in the automated teller machine 1, if authentication is not performed normally, the banknote reuse unit 21 erases the identification information stored in the memory 252. This makes it possible for the automated teller machine 1 to prevent fraudulent authentication attempts from succeeding even if the fraudulent attempts are repeated.

[0070] Furthermore, in the automated teller machine 1, when the identification information is set and the banknote transport unit 2 notifies the banknote reuse unit 21 of the identification information, if the banknote reuse unit 21 detects an operation within the safe 3, the notified identification information is stored in the memory 252. In this way, the automated teller machine 1 sets the identification information after confirming the authority to perform operations within the safe 3, thereby making it possible to prevent the identification information from being set fraudulently.

[0071] In the above embodiment, communication between the banknote transport unit 2 installed outside the safe 3 and the banknote reuse unit 21 installed inside the safe 3 is exemplified, but the units that perform the communication are not limited to those described above. For example, the communication method in the above embodiment may be applied to a case where the ATM control unit 4 installed outside the safe 3 and the banknote reuse unit 21 installed inside the safe 3 perform direct communication. In addition, the unit installed inside the safe 3 is not limited to the banknote reuse unit 21, and may be, for example, a coin reuse unit that stores coins and dispenses them. [Explanation of symbols]

[0072] 1…Automated teller machine 2...Banknote transport unit 3. Safe 4. ATM control section 11…Deposit port 12…Withdrawal port 13...Discrimination section 14...Transportation path 15...Banknote transport unit control section 16...Passing sensor 21…Banknote recycling unit 22…Recycling storehouse 23…Reject Warehouse 24...Transportation route 25...Cassette control section 26...Operation detection unit 41, 151, 251…CPU 42, 152, 252…Memory 153, 253…FPGA C1…Instruction C2…Authentication command C3: Data communication

Claims

1. performing a process of authenticating a first unit installed outside a storage facility of the automated teller machine and a second unit installed inside the storage facility by using a first data communication encrypted by a first encryption method; if the authentication in the authentication process is normally performed, the first unit transmits an instruction to the second unit through a second data communication encrypted by a second encryption method; the first unit executes a first process of encrypting identification information set in the first unit using the first encryption method and notifying the second unit of the encrypted identification information, and the second unit executes a second process of storing the identification information notified in the first process in a storage unit; In the authentication process, the first unit executes a third process of notifying the second unit of the identification information by the first data communication, and the second unit executes a fourth process of comparing the identification information notified in the third process with the identification information stored in the storage unit in the second process. A communication method comprising:

2. If the authentication is not performed normally, the second unit erases the identification information stored in the memory unit.

2. The communication method according to claim 1 .

3. The second unit executes the second process when the second unit detects an operation in the hangar when the identification information is notified from the first unit to the second unit.

3. The communication method according to claim 1 or 2.

4. A process in which a first unit installed outside a storage unit of an automated teller machine and a second unit installed inside the storage unit perform authentication using a first data communication encrypted by a first encryption method; a process in which, when the authentication is normally performed in the authentication process, the first unit transmits an instruction to the second unit through a second data communication encrypted by a second encryption method; a first process in which the first unit encrypts identification information set in the first unit using the first encryption method and notifies the second unit of the encryption, and a second process in which the second unit stores the identification information notified in the first process in a storage unit; a third process in which the first unit notifies the second unit of the identification information by the first data communication in the authentication process; and a fourth process in which the second unit compares the identification information notified in the third process with the identification information stored in the storage unit in the second process. A communication program that causes a computer to execute the above.

5. A first unit is installed outside a hangar, and a second unit is installed inside the hangar, performing a process of authenticating the first unit and the second unit using a first data communication encrypted by a first encryption method; if the authentication in the authentication process is normally performed, the first unit transmits an instruction to the second unit through a second data communication encrypted by a second encryption method; the first unit executes a first process of encrypting identification information set in the first unit using the first encryption method and notifying the second unit of the encrypted identification information, and the second unit executes a second process of storing the identification information notified in the first process in a storage unit; In the authentication process, the first unit executes a third process of notifying the second unit of the identification information by the first data communication, and the second unit executes a fourth process of comparing the identification information notified in the third process with the identification information stored in the storage unit in the second process. An automated teller machine characterized by:

Images