JP2010003130A - Unauthorized act prevention method for electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unauthorized act prevention method for an electronic device, allowing securing of high-level security even after disposal of a product, for example. <P>SOLUTION: The unauthorized act prevention method for a card reader 1 having a nonvolatile memory (ROM 12) storing at least an operation program and a memory (RAM 11) storing an erase program erasing the operation program includes: a first step for erasing the operation program by the erasure program when receiving a memory erase command from an upper device; and a second step for erasing the erase program. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fraud prevention method for preventing an illegal act on an electronic device that handles confidential data.

  In an electronic device such as a card reader, confidential data (for example, key data used for encryption processing) is held in a volatile memory backed up by a secondary power source, and is volatiled whenever necessary. The confidential data is read from the memory to the working memory, and various processes are executed. Since the confidential data is indispensable for the execution of various processes, it is normally held so as not to disappear. When any abnormality is detected, the power supply from the secondary power source and the main power source to the volatile memory is cut off to delete the confidential data.

  Further, in the card reader device with security function described in Patent Document 1, when a criminal tries to attach a skimming device and detects unpacking of the device housing, the memory is erased and the card reader device cannot be operated. To. As a result, crimes caused by unauthorized unpacking can be prevented.

JP 2001-291050 A

  However, in the card reader device according to Patent Document 1 described above, when the device casing is returned to the original position, the detection switch is returned to the original position, and then the hidden switch for recovering the operation is pressed, under certain restrictions. The operation is restored (paragraph number [0026] etc. in the specification of Patent Document 1). This means that the operating program has not been completely erased even if it is unpacked illegally. If the card reader device is discarded while the operation program remains, it may be misused. Therefore, it is preferable to completely erase the operation program in order to ensure high security. At this time, an erasing program for erasing the operation program is used, but the state in which the erasing program remains also causes a decrease in security. Because, when the card reader device is discarded (or recycled) with the erase program remaining, there is a risk that the erase program will be analyzed by a criminal and a method of avoiding the erase of the operation program can be conceived. Because there is sex.

  The present invention has been made in view of these points, and an object of the present invention is, for example, a method for preventing fraud in an electronic device that can ensure a high level of security even after the product is discarded. Is to provide.

  In order to solve the above problems, the present invention provides the following.

  (1) A method for preventing fraud in an electronic device having at least a non-volatile memory in which an operation program is stored and a memory in which an erase program for erasing the operation program is stored. An electronic device device fraud prevention method comprising: a first step of erasing the operation program by the erasure program when receiving a command; and a second step of erasing the erasure program.

  According to the present invention, in the electronic device device that has received the memory erasure command from the host device, the operation program stored in the non-volatile memory is erased by the erase program stored in the memory, and then the erase program is also erased. Therefore, when the electronic device is discarded or when the electronic device is recycled, the erasure program does not remain. Therefore, it is possible to prevent an erasure program from being analyzed by a criminal or the like, and as a result, high security can be ensured. Also, according to the method for preventing fraud according to the present invention, the contents stored in the nonvolatile memory including the erasing program can be completely erased. For example, the ROM writer can be removed by removing the nonvolatile memory such as ROM. Even if ROM data is read out, program analysis is impossible. In this respect as well, it is possible to prevent a criminal from analyzing a program for illegal use.

  Here, the erasure program need not always be stored in the memory in which the erasure program for erasing the operation program is stored. For example, it is sufficient to store temporarily when the operation program erasing process is executed (just before execution).

  (2) In the first step, when a memory erase command is received from a host device, the erase program copied from the nonvolatile memory to the memory and the erase program copied to the memory are executed. And a method for preventing fraudulent behavior of the electronic device.

  According to the present invention, when the memory erase command from the host device is received, the first step described above copies the erase program from the nonvolatile memory to the memory, and then erases the program copied to the memory. Therefore, it is only necessary to prepare a memory for saving the erase program, and the security can be easily improved. When a memory other than the non-volatile memory already exists in the electronic device, the memory can be used to suppress an increase in the number of parts and prevent an increase in cost. If the memory for saving the erasing program is nonvolatile, some processing for erasing the erasing program is required by connecting a dedicated IC card to the electronic device.

  (3) The method of preventing fraudulent behavior of an electronic device device, wherein the memory is a volatile memory, and the second step is executed by cutting off power supply to the electronic device device.

  According to the present invention, the above-mentioned memory is a volatile memory, and the second step is executed by cutting off the power supply to the electronic device apparatus. The erase program can be erased with a simple configuration such as the above.

  (4) A method of preventing fraudulent behavior of an electronic device, comprising a step of erasing data stored in the nonvolatile memory.

  According to the present invention, since the data stored in the above-described nonvolatile memory is also erased, security at a higher level can be ensured.

  (5) The method for preventing fraudulent behavior of an electronic device, wherein the erasing program is downloaded from the outside before the erasing operation.

  According to the present invention, since the above-described erasing program is downloaded from the outside before the erasing operation, security can be ensured, and a memory in the electronic device apparatus can be used to store an erasing program that is not normally used. It is not necessary to increase the capacity.

  According to the present invention, when there is an erasing program for erasing the operation program, even the erasing program is erased, so high security is ensured even after product disposal or recycling. can do. In addition, even when the nonvolatile memory is removed from the electronic device, it is possible to perform program analysis for illegal use (for example, avoiding erasure of an operation program) by erasing the erase program. It can be prevented in advance.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[Configuration of electronic device]
FIG. 1 is a block diagram of a card reader 1 used in a fraud prevention method according to an embodiment of the present invention. In the present embodiment, a card reader 1 will be described as an example of an electronic apparatus device.

  The card reader 1 includes a CPU 10, a RAM 11, and a ROM 12, and various connections are made via a bus. Also, for example, it has a shutter 13 provided for the purpose of protecting the inside of the apparatus or card protection during card processing, a sensor 14 provided for grasping the card position inside the apparatus, etc., and various connections are made. ing.

  The CPU 10 manages the overall control of the card reader 1. For example, a command for opening / closing the shutter 13 or notifying the card position detected by the sensor 14 is transmitted / received. It also serves to transfer various data between memories.

  The RAM 11 is an example of a volatile memory, and provides a work area for the CPU 10 to execute a program. In the work area, work data necessary for various operations is stored, and electronic information from the ROM 12 is also stored. In the present embodiment, the RAM 11 is assumed to be built in the CPU 10, but the RAM 11 may be independent from the CPU 10. The ROM 12 is an example of a non-volatile memory, and stores at least an operation program for operating the card reader 1 and other electronic information such as confidential data. In particular, in this embodiment, an erasing program for erasing the operation program is already stored. Note that the erase program may be downloaded from an external PC or the like immediately before the erase operation. Further, as other nonvolatile memory, a flash memory, an EEPROM, or the like may be used. Further, the ROM 12 may be built in the CPU 10 or the RAM 11 and the ROM 12 may be built in the CPU 10. Furthermore, in order to improve security, the terminals of the RAM 11, ROM 12 and CPU 10 are covered with resin, adhesive, etc. (the entire circuit board may be covered), and the signal cannot be measured with a measuring instrument such as an oscilloscope. Good.

[How to prevent fraud]
FIG. 2 is a flowchart showing a flow of information processing related to the fraud prevention method according to the embodiment of the present invention.

  In FIG. 2, for example, when the card reader 1 is discarded, the card reader 1 accepts a (memory) erase command from an externally connected PC or the like (which may be a host device of the card reader 1) (reception) (Step S1). Then, the CPU 10 of the card reader 1 copies the erasing program stored in the ROM 12 to the RAM 11 (Step S2). Thereafter, the CPU 10 executes an erasing program on the RAM 11 (step S3), and continues the processing until all the stored contents of the ROM 12 storing the operation program and the like are erased (step S4: NO). When erasure of the contents stored in the ROM 12 is completed (step S4: YES), an erasure completion display is performed (step S5). This erasure completion display may be displayed on a screen of an externally connected PC or the like, or may be displayed on an LED or the like on the substrate.

  Thereafter, when the power of the card reader 1 is turned off (step S6), the power supply to the card reader 1 is cut off and the stored contents of the RAM 11 are also erased, so that both the operation program and the erase program are erased from the card reader 1. (Step S7). That is, the card reader 1 is in an unrecoverable state. In this regard, in a general electronic device, even if the power is turned off, the operation program and the erase program are not erased. However, in the card reader 1 according to the present embodiment, when the power is turned off, that is, when the operation program for causing the shutter 13 and the sensor 14 to function is erased by the erase program in order to improve security, the erase is thereafter performed. The program itself is also erased. Thereby, even after the card reader 1 is discarded, high security can be ensured. In particular, a card reader in the electronic device apparatus handles secret information related to a card holder such as an account number. Therefore, even after the card reader 1 is discarded, higher security must be ensured. This is to avoid the risk that the secret information is leaked by analyzing the operation program and the erasure program by a criminal. In this respect, according to the card reader 1 according to the present embodiment, even the operation program and the erasure program are not left, so that these are not analyzed and higher security can be ensured. In addition, about above-mentioned step S6, you may comprise so that the card reader 1 may turn OFF a power supply itself automatically.

  In this embodiment, the erase program is copied to a volatile memory, and the erase program is automatically erased when the power is turned off. However, the erase program may be copied to a nonvolatile memory. In this case, the erase program is stored in a dedicated IC card and the card is read (in this case, the erase program is temporarily expanded in the RAM 11), and the erase program temporarily stored in the nonvolatile memory is stored. It may be erased. Similarly, the operation program stored in the nonvolatile memory may be erased.

  In the present embodiment, the program erasure process is executed in response to the receipt of the erase command (step S1 in FIG. 2). For example, the switch ( For example, this may be executed when a switch for detecting unauthorized unpacking is turned on. The card inserted when the card reader 1 is a card reader may be a contact type IC card or a non-contact type IC card. The card reader may be a motor type that carries a card by a motor, a dip type that manually inserts a card, or a swipe type that swipes a card. The type of the card reader may be an IC card reader or a magnetic card reader.

  Further, in the present embodiment, the operation program and the erasure program are stored in advance in the ROM 12 (separate storage areas), but may be stored in separate memories. When the erase program is executed on the nonvolatile memory, the erase program and the operation program may be separate memories, or one nonvolatile memory is divided and only the operation program area is erased. It is good as well. In this embodiment, attention is focused on the step of erasing the operation program and the erasure program. However, for example, there may be a step of erasing confidential data stored in the nonvolatile memory (this step is a program). Before or after erasure).

[Main effects of the embodiment]
According to the fraud prevention method of the card reader 1 according to the present embodiment, the erasure program for erasing the operation program is also finally erased. Therefore, when the card reader 1 is discarded or recycled, the criminal Analysis of the erasure program can be prevented in advance, and as a result, high security can be ensured.

  Further, not only the card reader 1 cannot be recovered, but also the erase program is erased. Therefore, even when the ROM 12 or the like is removed, the erase program is not analyzed. Also in this point, security can be improved.

  Further, by executing the erasure program stored in the ROM 12 after temporarily saving it in the RAM 11, it is possible to easily improve security using existing hardware resources.

  The fraud prevention method of the card reader 1 according to the present invention is useful as a method that can prevent program analysis for illegal use, which may be performed after product disposal, for example.

It is a block diagram of the electronic device apparatus used with the fraud prevention method which concerns on embodiment of this invention. It is a flowchart which shows the flow of the information processing regarding the fraud prevention method which concerns on embodiment of this invention.

Explanation of symbols

1 Electronic equipment (card reader)
10 CPU
11 RAM (volatile memory)
12 ROM (nonvolatile memory)

Claims (5)

An electronic device device fraud prevention method comprising: a non-volatile memory storing at least an operation program; and a memory storing an erasure program for erasing the operation program,
A first step of erasing the operating program by the erasing program when a memory erasing command is received from a host device;
And a second step of erasing the erasure program. The method of preventing fraud in an electronic device. The first step is a step of copying the erase program from the nonvolatile memory to the memory when a memory erase command is received from a host device;
The method according to claim 1, further comprising: executing the erasure program copied to the memory.   3. The fraudulent electronic device apparatus according to claim 1, wherein the memory is a volatile memory, and the second step is executed by cutting off power supply to the electronic device apparatus. Action prevention method.   4. The method of preventing fraud in an electronic device according to claim 1, further comprising a step of erasing data stored in the nonvolatile memory.   2. The method of preventing fraudulent behavior of an electronic device according to claim 1, wherein the erasing program is downloaded from outside before the erasing operation.

Images