JPH0143343B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for handling a personal identification number (so-called PIN number) used in an identification card (so-called ID card) that records machine-readable data, and in particular, a method for handling a personal identification number (so-called PIN number) used in an identification card (so-called ID card) that records machine-readable data. secret number (along with machine-readable data if necessary)
This invention relates to a method of handling personal identification numbers in which the correct owner is identified by the secret number.

In the case of a personal identification number (hereinafter referred to as PIN) used for automatic cashing services, etc., it is necessary to ensure that no one other than the owner can use the card.

When working with PINs, there are basically two steps involved: personalizing the card and identifying the user.
In other words, during the card personalization process, the PIN
The coded PIN and data specific to the user and bank are recorded on the ID card, and the user identification (user verification) process requires personalization each time the card is used. The code determined at the time is confirmed.

Many ways of encoding PINs are known. For example, in the simple system described in U.S. Patent No. 3,657,521, user-related data such as an account number (hereinafter abbreviated as PAN) and a PIN given by the card issuer are collected using a predetermined function. It is designed to be combined.

To identify the user, the user must enter a PIN into the device.
After entering the PIN, the relationship between the PIN and the account number will be checked.

However, in such conventional systems, if you have several cards at your disposal, it is possible to find the association between card data and PIN and extract the correct PIN from the stolen card. It is.

In recent years, “NBS Data Encryption Standard
(This method is also called DES.)
It has become common practice to link PINs with user-specific data using complex calculation methods such as (U.S. Patent No. 4123747
144640]) Such a coding system is called Clear text data.
It has the characteristic that there is no problem even if the calculation method is revealed as long as the code used to uniquely code the code according to the calculation method is kept secret. Therefore, the calculation method can also be obtained in the form of an IC module. To encode user-specific data,
Supply PAN and PIN to e.g. DES module,
At the same time, secret information (code) is supplied and encoded. The results of the encoding are recorded on a card for later reference. When using such a DES module, the security of the system depends on whether the code is kept secret. That code must be stored in several places (card issuer, cashing machine, etc.) in order to be used in currently known systems.
Once that code is known, any card processed by that code can be counterfeited using the DES module. In order to reduce this risk, it would be possible to divide the issued cards into relatively small groups and use a different code for each group, but this would result in higher costs due to mechanical and technical reasons. There is.

ID to increase safety when handling PIN
The data on the card is encoded in two stages (two-
level coding). (West German Patent Application No. 2901521) In this system, the person who is to become the card owner (hereinafter referred to as the prospective owner) is given a PAN and
A PIN is given (see Figure 1), and the PIN is freely selected by the prospective owner, for example, with a four-digit number. A first encoding of the PAN takes place here. At this time, the PIN is combined with the first secret number and used as a code. The first code number Y ₁ obtained thereby is converted into a second code number Y ₂ by a predetermined conversion. For example, the check number PCN recorded on the card is its second code number Y ₂
obtained by decoding. The second secret number is then used as the code.

The PAN read from the card is used as the PIN (entered by the user) to identify the user.
and a first secret number. At this time, if the data is correct, the first code number _Y1 is obtained. Furthermore, the check number PCN read from the card is encoded using a second secret number. This results in a second code number. The second code number must satisfy the conversion determined by the issuance or personalization of the card.

Since this system uses two secret numbers, ie, two different codes, it is more secure than the previously described systems.

The disadvantage of this system is that it requires a device to store the second code, and the associated increased secrecy.

This is particularly true in offline systems that go beyond a particular bank, ie, where users use not only the particular bank's equipment but also other banks' equipment.

As the number of devices increases, the efficiency of the system decreases because all codes used must be stored within each device. The risk also increases as the number of devices increases, since each device holds all the secrets necessary to operate the system.

In view of these circumstances, it is an object of the present invention to provide a method for handling personal identification numbers that maintains the security of two-step encoding and is more efficient.

The method of the invention is characterized in that the secret information recorded on the ID card is processed in at least one stage of the two-stage encoding.

Thus, by processing the secret information (code) recorded on the card during at least one stage of the two-stage encoding, the storage required by the system becomes acceptable. At this time, another code for further increasing security is recorded on each card without using any extra special measures.

As will be described later, according to the method of the present invention, all secret information is provided in a simple manner to each stage of handling the PIN (setting stage for setting the PIN, personalization stage for issuing the card, and user identification stage). , and
The secret information needed to determine the PIN is not revealed in its entirety at any stage.

Efforts are made to record code information on ID cards in such a way that the information cannot be determined or imitated, or even if it is possible to do so. Use extremely advanced and highly secure technology that does not pay off in terms of profits. Any method may be used to record the code information on the ID card as long as it satisfies the above conditions. For example, it is recorded using difficult-to-specify magnetic materials, electrical recording materials, fluorescent materials, etc.
Similarly, characteristics such as manufacturing tolerances and visually encoded records specific to the card may be used.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing an example of a conventional PIN handling method. This conventional method is divided into two steps: personalization 1 and user identification 2. PAN3 and PIN4 will be given to the prospective owner for personalization.
PIN4 can be selected by the prospective owner as a four-digit number, for example. Here, PAN3 is encoded in the first encoding module 7. At this time, PIN4 is combined with first secret number 5 and used as a code. The so-called first code number Y ₁ thus obtained is converted into a second code number Y ₂ by a predetermined conversion.
For example, the check number recorded on card 9
PCN assigns its second code number Y ₂ to module 1
Obtained by decoding within 0. At this time, the second secret number 11 is used as a code.

When identifying the user, the PAN3 read from the card (entered by the user)
It is encoded (in encoding module 7') using PIN4 and said first secret number. At this time, if the data is correct (obtained code number
Y ₁ ′) corresponds to the first code number Y ₁ . Additionally, the check number PCN read from the card
is encoded within the module 12 using said second secret number 11. This causes the second
The code number Y ₂ is obtained. Both code numbers Y ₁ ′,
Y ₂ must satisfy the transformation determined by the issuance or personalization of the card, which is checked by the comparator 15.

As is clear from FIG. 1, in conventional systems all data, such as secret codes, must be provided to both the personalization device and the user identification device. Therefore, there is a relatively high risk that secrets will be leaked or that data necessary to operate the system will be discovered.

FIG. 2 shows an example of a system implementing the method of the invention.

In the method of the present invention, as shown by the chain line in FIG. 2, the handling of the PIN consists of a setting stage in which the user is given the user's unique data - PAN, and an ID card with the necessary user data and bank data. It takes place in three stages: a personalization stage, which records everything, and a device stage, which reads the data on the ID card and checks whether it corresponds to the entered PIN.

User-specific data PAN at the configuration stage
It is convenient to allocate 18 to the intended user.

For example, the four-digit number PIN19 can be selected by the user himself if desired. A PIN selected by the user and known only to that user.
19 is sent to the first arithmetic module 20 (of the setting device 15) together with the PAN 18, and is processed using the first secret code generated from the code storage device 21, and is made into an intermediate value IV. Its median value IV
and the user's PAN are recorded on the magnetic tape 22.

The magnetic tape 22 created by such a setting device 15 is sent to the central personalization device 16, where an ID card 23 is finally created. At the central personalization device 16, the data on the magnetic tape 22 is read and applied to a second computing module 24. This second arithmetic module 24 may have the same structure as the first arithmetic module 20. A second code for processing the data is obtained from the secret information (recorded on the card) (see hatched area 7) by a reading head 28 attached to the code reader 25.
The code result, ie the code number CN, is recorded on the magnetic track 26 of the card 23, for example, together with the user-specific data PAN.

When identifying a user, the user must
Input PIN 19' into identification device 17. That PIN
is encoded using the first secret code from said code storage device 21 together with the PAN read from the card. The result is immediately sent to arithmetic module 24' and encoded using a second secret code. This second secret code is read from the card 23 by the reading head 28' of the code reader 25'.

The result of such double encoding matches the code number CN recorded on the magnetic track 26 of the card 23 if the sequence is correct. The comparator 27 displays the check result by means of an appropriate electronic signal and sends a YES signal to the display device or electronic device in the device allowing the check to proceed to the next step, such as disbursing the requested amount.

In the device of this embodiment, modules that must be kept secret are indicated by hatching in FIG. As mentioned above and as is clear from FIG. 2, the secret information required to determine the PIN cannot be directly accessed in any of the three steps described above. This fact is combined with the fact that two-step encoding was used to make one of the codes secret (e.g. unique to each card).
The safety of devices that handle PINs has been increased.

In order to prevent the signals between the reading head 28' and the code reader 25' from being stolen, the reading head 28' and the code reader 25' are housed in a common sealed frame in the actual device, and the reading head 28' and the code reader 25' are housed in a common sealed frame. ID card 23 from the slit
is inserted.

As mentioned above, there are several ways to create an ID card with code information that cannot be determined or imitated.

For example, US Pat. No. 3,620,590 discloses a method of using holography to protect confidential information. In this method, the desired visually coded information is recorded in a hologram on the ID card by a special filter (master code filter). This encoded information can only be reproduced using a master code filter. This master code filter is made part of the reading device and is kept inaccessible to outsiders.

Any method for creating information that cannot be reproduced without using special means that is inaccessible to outsiders or that cannot be reproduced without special knowledge can be used in the present invention.

Similar to the above example, information can be recorded on an ID card using magnetic or fluorescent patterns that can only be read with special, generally unavailable equipment and appropriate knowledge. You may also do so.

In the above example, the same encoding principle (NBS data encryption standard calculation method) was used in both encoding stages to simplify the explanation, but the present invention also includes various other encoding methods. can be used. It is also possible to use different calculation schemes in both encoding stages. Irrespective of the encoding principle itself, the essential feature of the invention is that the encoding takes place in two spatially different locations and that secret information specific to the card is used for the encoding. be.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a conventional PIN handling system, and FIG. 2 is a diagram for explaining an example of a system implementing the method of the present invention. 15...setting device, 16...personalization device, 17
...Identification device, 18...PAN, 19...PIN,
20, 20', 24, 24'... calculation module,
21... code storage device, 22... magnetic tape,
23...ID card, 27...comparator.

Claims (1)

[Scope of Claims] 1. A secret number (PIN) is given to the owner of the ID card 23 having machine-readable data, and the secret number (PIN) is encoded in two stages.
Personalize ID cards, and each time the user is verified,
In the method for handling a personal identification number in which the secret number (PIN) is confirmed using the encoding result, secret information 7 is recorded on the ID card 23;
The secret number (PIN) is processed together with the user data (PAN) to obtain an intermediate value (IV) in the first stage of the two-stage encoding during the personalization, and the intermediate value (IV) is In the second stage of the two-stage encoding, the secret information 7 read from the ID card 23 is also used and processed to obtain a code number (CN).
along with the user data (PAN) mentioned above.
D. A method characterized by recording on a card 23. 2. In the user confirmation process, the secret number (PIN) entered by the user is transferred to the ID card 2.
The intermediate value (IV) is processed together with the user data (PAN) read from the ID card 23, and the intermediate value (IV) is immediately converted into a code number (CN). Claim 1, characterized in that the code number (CN) obtained is also compared with the code number (CN) recorded on the ID card 23 using the secret information 7. Method. 3. The method according to claim 1 or 2, characterized in that the two stages of encoding are performed at spatially separate locations. 4. The method according to claim 3, characterized in that the encoding in the first step is performed in a distributed manner at each ID card issuer. 5. The method according to claim 3 or 4, characterized in that the encoding in the second stage is carried out centrally at an institution that personalizes cards. 6. A method according to any one of claims 1 to 4, characterized in that the secret information 7 on the ID card 23 is obtained from characteristics specific to that card. 7. The method of claim 6, wherein the characteristic is at least one of a holographic, magnetic, fluorescent or photoelectric pattern.