JPH03224046A - Portable electronic device - Google Patents

Abstract

PURPOSE:To ensure a security level of higher flexibility in each area of a memory by deciding the propriety of accesses for each area of the memory based on the result of mutual confirmation. CONSTITUTION:An IC card 1 consists of a part where such basic functions are carried out as a read/write part 11, an identification number setting/collating part 12, a ciphering/deciphering part 13, etc., and a supervisor 14 which controls these basic functions. The card 1 receives a telegram from a terminal equipment 8 and carries out selectively a mutual confirmation preparatory flow based on the function code of the telegram. Then the comparison is performed between the confirmation information contained in the telegram and that stored previously in an internal RAM. The result of this comparison is stored and at the same time the attribute information showing the propriety of accesses is added to each area of a data memory based on the stored result of comparison. Thus the propriety of access is decided based on the result of comparison and the attribute information. Thus a security level of higher flexibility is secured in each area of the data memory.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to erasable non-volatile memory and C
The present invention relates to a portable electronic device called an IC card, which has a built-in IC (integrated circuit) chip having a control element such as a PU.

(Prior Art) As a function required of recent IC cards, external devices (
A mutual authentication function with a terminal device that handles IC cards (such as a terminal device that handles IC cards) has been proposed. In this case, an access control method has been used in which access is not possible unless mutual authentication is performed with the external device.

(Problem to be Solved by the Invention) In this case, it is impossible to set an area that can be accessed without performing mutual authentication depending on the application, and there is a problem that the security level lacks flexibility.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a portable electronic device that can provide more flexible security levels to each area of its memory.

[Structure of the Invention] (Means for Solving the Problems) The present invention has at least a memory and a control element that accesses the memory, and selectively exchanges data with the outside. and a portable electronic device in which the memory is divided into a plurality of areas, a receiving means for receiving first encrypted data obtained by encrypting at least first data using first key data; an encryption means for encrypting data using first key data to generate second encrypted data; and second encrypted data generated by the encryption means and first encrypted data received by the receiving means.
and means for determining whether or not each area of the memory can be accessed based on the comparison result of the comparison means.

(Operation) In connection with mutual authentication, a more flexible security level can be given to each area of the memory by determining whether or not each area of the memory can be accessed based on the authentication result.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 6 shows an example of the configuration of a terminal device that handles an IC card as a portable electronic device according to the present invention. That is, this terminal device 8 allows the IC card 1 to be connected to a control section 3 consisting of a CPU, etc. via a card reader/writer 2, and also connects the control section 3 with a keyboard 4, a CRT, etc.
It is constructed by connecting a display device 5, a printer 6, and a floppy disk device 7.

The IC card 1 is held by the user and is used to refer to a personal identification number known only to the user when purchasing a product, for example, and to store necessary data. Its functional blocks are shown in Fig. 5. It is further comprised of parts that execute basic functions such as a read/write section 11, a password setting/password verification section 12, and an encryption/decryption section 13, and a supervisor 14 that manages these basic functions. The read-write section 11 has the function of reading, writing, or erasing data from a data memory 16, which will be described later. The password setting/password verification unit 12 has a function of storing the password set by the user and prohibiting reading of the password, as well as verifying the password after setting the password and granting permission for subsequent processing. The encryption/decryption unit 13 performs encryption and encryption of encrypted data to prevent leakage and forgery of communication data when transmitting data from the control unit 3 to another terminal device via a communication line, for example. This is for decoding. The supervisor 14 uses a card reader/
This is a function of decoding a function code input from the writer 2 or a function code to which data is added, and selecting and executing a necessary function among the basic functions.

In order to perform these various functions, the IC card 1 has a control element (for example, a CPU) 1, as shown in FIG.
5, it is composed of a data memory 16, a program memory 17, and a contact part 18 for obtaining electrical contact with the card reader/writer 2, and the part within the broken line (control element 15, data memory 16, The program memory 17) is composed of one IC chip (or a plurality of IC chips) and is embedded within the IC card body.

The program memory 17 is composed of, for example, a mask ROM, and stores a control program for the control element 15 including subroutines for realizing each of the basic functions described above.

The data memory 16 is used to store various data, and is composed of erasable nonvolatile memory such as EEFROM.

For example, as shown in FIG. 3, the data memory 16 includes one common data file (hereinafter abbreviated as CDF) 21 that is commonly used by all applications, and a plurality of application data files that are used individually for each application. (hereinafter abbreviated as ADF) 22a, 2
2b and 22c, each ADF 22
a22b and 22c each have the data file name - (
D F N) is given.

In the example shown in FIG. 3, the CDF 21 contains designation key data a indicated by the key data number KIDOI.
aa, and internal key data bbb indicated by key data number KIDO2, and which is activated by DFN-AAA, includes designation key data CCC indicated by key data number KIDO3, and internal key data bbb indicated by key data number KIDO4. The specified key data ddd is included. The ADF 22b indicated by DFN-BBB contains internal key data eee indicated by key data number KIDO5.
, and a data area indicated by area number AIDS5. In particular, the data area is given attribute information indicating that it can be accessed if authentication is confirmed through authentication processing using internal key data within the ADF 22b. Also, D
The ADF 22c indicated by FN-CCC has internal key data f indicated by key data number KID80.
f, a data area indicated by area number AIDS6, and a data area indicated by area number AIDS7. In particular, the data area indicated by the area number AIDS6 is given attribute information that allows access if authentication is confirmed through authentication processing using internal key data in the CDF21, and the data area indicated by the area number AIDS7 is , attribute information indicating that access is possible when authentication is confirmed through authentication processing using internal key data in the CDF 21 or internal key data in the ADF 22C is given.

Here, the designation key data is key data for the terminal device 8 to authenticate the IC card 1, and the internal key data is the key data for the IC card 1 to authenticate the terminal device 8.

Next, an overview of the operation of the IC card 1 will be explained using FIG. When the IC card 1 receives the message shown in FIG. 2(a) from the terminal device 8, it selectively reads the message shown in FIG. 1(a) from the function code.
Execute the mutual authentication preparation flow in a). These processes are performed by the control element 15 according to the program in the program memory 17. That is, first, it is determined whether the ADF is a selective flow or not by checking the internal RAM (RAM in the control element 15).
) in the selected ADF specific information. At this time, if it is not the selected flow, the key data number (K
ID), and if it is a selective flow, then CDF21
Find the KID within and also within the selected ADF. If it is not found at this point, an error status will be output.

If found, the corresponding key data is internally read and checked to see if it is normal. At this time, if it is not normal, an error status is output. If normal, the random number information A in the message and the key data are stored in a predetermined area of the internal RAM.

Next, random number information B is generated according to a predetermined algorithm using this random number information A, the card-specific number set at the time of card issuance, and card random number information stored in advance as an initial value in the data memory 16. ,
Rewrite this as new card random number information.

Next, check again whether the ADF is a selective stream, and if it is not a selective stream, find the KID of the internal key data from the CDF21, and if it is a selective stream, check the internal key data KID in the CDF21 and the selected ADF.
Find KID from inside (ADF is prioritized). If not found, output an error status. If found, the corresponding key data is read internally and checked to see if it is normal. At this time, if it is not normal, an error status is output.

Now, if normal, the previously generated random number information B is encrypted using the found internal key data as an encryption key, and the result is stored in a predetermined area of the internal RAM as authentication information C2X. Then, the internal key data KID and random number information B are output, and this flow ends.

Through this flow, random number information and key designation information can be shared in mutual authentication between the terminal device 8 and the IC card 1.

Next, when the message shown in FIG. 2(b) is received, the flow shown in FIG. 1(b) is selectively executed from the function code. That is, first, it is checked whether the mutual authentication preparation command described above has been executed, and if not, an error status is output.

If it has been executed, the authentication information C2 in the next input message
and the authentication information C2X that was previously stored on the internal RAM.
If they match, turn on the match flag, otherwise turn it off. At this time, depending on whether the internal key data belongs to ADF or CDF, either the ADF correspondence match flag or the CDF correspondence match flag is turned on or off. Next, the random number information A previously stored in the internal RAM is encrypted using the specified key data as the encryption key, and the result is output as the authentication information CIX together with the result of the matching flag above, and this flow is executed. finish.

This flow enables mutual authentication with the terminal device 8.

Next, when the message shown in FIG. 2(c) is received, the ADF selection flow shown in FIG. 1(C) is selectively executed from the function code. That is, first, it is checked whether the DFN in the message is registered in the data memory 16 of the IC card 1, and if it is not found, an error status is output.

If found, the ADF compatible match flag among the C2/C2X match flags is turned off. Next, the specified DFN
It holds the unique information corresponding to in the internal RAM and outputs the normal completion status.

Next, when the read command message shown in FIG. 2(d) or the write command message shown in FIG. 2(e) is received, the flow shown in FIG. 1(d) is selectively executed from the function code. That is, first determine whether the ADF has been selected,
If it is not selected, find the area number (AID) in the input message from CDF21, and if it is selected, select A
Find AID in DF and CDF21.

At this time, if it is not found, an error status is output.

If found, it is determined whether or not it is necessary to check the previous match flag by referring to the attribute information of the correspondingly stored area. If necessary, it is determined whether it is an ADF compatible match flag, a CDF compatible match flag, or either one.

If the ADF compatible match flag is required or if either is acceptable, refer to the ADF compatible match flag and check whether it is turned on. If off, output error status.

Furthermore, if the CDF correspondence match flag is required or either is acceptable, the CDF correspondence match flag is referred to and checked to see if it is turned on. If it is off, it will output an error status.

Then, according to the function code in the message, the corresponding read or write processing is performed and the processing result is output.

Next, the operation of the IC card 1 with respect to the key data and area configuration as shown in FIG. 3, for example, will be explained. In Fig. 3, as described above, in this state, for mutual authentication when ADF selection is not performed, the key data of KIDOI is used as the designated key data, and the key data of KIDO2 is used as the internal key data. is used.

In addition, when ADF22g is selected by DFN-AAA, the specification key data is KID03 or KID03.
IDO4 key data or KIDOI key data is used, and KIDO2 key data is used as internal key data.

Similarly, when the ADF 22b is selected by DFN-BBB, the key data of KIDOI is used as the specification key data, and the key data of KIDO5 is used as the internal key data.

Now, in order to access the area of AIDS5 in the ADF 22b, the attributes of this area require internal key data in the ADF. Therefore,
Mutual authentication must be performed after selecting the ADF 22b. If ADF22b is selected after mutual authentication, the internal key data used for this mutual authentication is KIDO2.
This is because it becomes the key data.

Furthermore, in order to access the area of the AI DS 6 in the ADF 22c, the attributes of this area require internal key data in the CDF 21. Therefore, it is necessary to select the ADF 22c and access the area after mutual authentication. Furthermore, the AIDS7 area can be accessed even if the ADF 22c is selected after mutual authentication or vice versa.

Further, in particular, if the ADF 22b is selected and the ADF 22c is selected after mutual authentication is executed, access to the AIDS7 area becomes impossible.

In this way, it is possible to compare cards internally in mutual authentication, obtain the comparison results, store the comparison results, and access each area of the data memory using the comparison results. Attribute information indicating the information is added, and at the time of access, it is determined whether access is possible based on the comparison result and the attribute information. Therefore, a more flexible security level can be provided to each area of the data memory.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide a portable electronic device that can provide a more flexible security level to each area of the memory.

[Brief explanation of drawings]

The figures are for explaining one embodiment of the present invention, and FIG. 1 is a flowchart explaining an overview of the operation of the IC card, FIG. 2 is a diagram showing examples of various command message formats input to the IC card, and FIG. 3 is a diagram showing the file structure of the data memory, FIG. 4 is a block diagram showing the schematic configuration of the IC card, and FIG. 5 is a diagram showing the functional blocks of the IC card.
FIG. 6 is a block diagram showing the configuration of the terminal device. °1...IC card (portable electronic device), 8,
...Terminal device, 15... Control element, 16
・・・・・・Pig memory (non-volatile memory), 17...
...Program memory, 21...Common data file (CDF), 22 a, 22
b, 22c...-7 Briquection data file (ADF).

Claims (1)

[Claims] The device has at least a memory and a control element that accesses the memory, selectively transmits and receives data to and from the outside, and the memory is divided into a plurality of areas. A portable electronic device comprising: receiving means for receiving first encrypted data obtained by encrypting at least first data using first key data; 2
an encryption means for generating encrypted data; a comparison means for comparing second encrypted data generated by the encryption means with first encrypted data received by the receiving means; and a comparison result of the comparison means. A portable electronic device characterized by comprising means for determining whether or not each area of the memory can be accessed based on the above-mentioned information.