KR20070062398A - Rfid tag authentication apparatus and method in rfid system - Google Patents

Abstract

A device and a method for authenticating a tag in an RFID system are provided to reduce quantity of calculations for finding a tag ID in a backend database while protecting privacy of the tag and keeping conventional security functions. A database(431) stores grouped RFID tag information including secret group information and secret tag information. A secret group information searcher(433) finds a group of the tag requesting authentication by repeatedly calculating the secret group information stored in the database through a hash chain based on the hash algorithm and comparing the calculated value with a secret group information conversion value. A secret tag information searcher(435) searches whether the secret tag information of the tag requesting the authentication is found in the database by repeatedly calculating the secret tag information of the found group through the hash chain and comparing the calculated values with the secret tag information conversion value.

Description

Tag authentication apparatus and method in RFID system {RFID tag authentication apparatus and method in RFID system}

1 is a view showing a basic structure of an RFID system,

2 is a view showing an embodiment of a wireless recognition medium of the RFID system according to the present invention;

3 shows the basic structure of a hash chain,

4 is a diagram illustrating an embodiment of a tag authentication device of an RFID system according to the present invention;

5 is a diagram illustrating a DB structure of a backend database;

6 is a view showing an embodiment of a tag authentication method in an RFID system according to the present invention;

7 shows a flow chart of the method according to FIG. 6, FIG.

FIG. 8 is a flowchart showing in more detail the secret group information retrieval step S760 of FIG. 7; and

9 is a flowchart illustrating the secret tag information retrieval step S770 of FIG. 7 in more detail.

The present invention relates to an apparatus and method for tag authentication in a radio frequency identification (RFID) system, and more particularly, to a wireless identification tag authentication device that enables rapid authentication while solving a privacy problem using a hash algorithm. It's about how.

An RFID system is an automatic recognition technology system that uses radio frequency to read or record information about an object without physical contact. The RFID system basically consists of a wireless identification tag, a reader and a back-end database.

However, the RFID system's ability to be recognized without physical contact creates a number of security issues that have not previously occurred in terms of safety and privacy. In other words, in the case of a tag that transmits identifiable information as it is, communication between the tag and the reader is likely to be intercepted by an attacker. In addition, the attacker can perform a tracking attack on the tag location based on the eavesdropping information, which is directly connected to the privacy violation of the consumer. Therefore, a lot of research is being conducted to solve the security problem (particularly the tag privacy problem) in such an RFID system.

There are two methods of tag authentication to solve tag privacy problem.

The first method is a paper entitled "Cryptographic approach to privacy friendly tags" published by RFID Privacy Workshop by M.Ohkubo, K.Suzuki, S.Kinoshita. Presented. This method fully supports privacy protection for tags, but has a problem in that the amount of tag retrieval required for tag authentication on the back-end database is equal to the total amount of irradiation for all tags stored in the database. As a result, tag authentication consumes a lot of time and resources, which reduces efficiency.

The second method is a "Hash-based enhancement of location privacy for radio-frequency identification devices using varying identifiers" paper, published in PerSec 2004 by Dirk Henrici and Paul Muller, which updates tag IDs in both tags and databases based on hash. We proposed a protocol to prevent location tracking attacks. In addition, unlike the previous method, the scheme stores the H (ID) and ID values in the database so that the tags can be quickly searched in the database with the H (ID) values transmitted by the tags. However, if the authentication process is not completed properly between the tag and the database, the ID value inside the tag is not updated, so the tag transmits the same H (ID) value for the repeated query of the reader. Therefore, there is a disadvantage that a location tracking problem of a tag may occur.

The technical problem to be achieved by the present invention is tag authentication in an RFID system that can protect the privacy of the tag and at the same time reduce the amount of computation to find the tag ID stored in the back-end database while maintaining the security of existing techniques To provide a device.

In addition, the present invention provides a tag authentication method in an RFID system that protects the privacy of a tag and at the same time reduces the amount of computation required to find a tag ID stored in a back-end database while maintaining the security of existing techniques.

In order to achieve the above technical problem, a tag authentication medium of an RFID system according to the present invention stores secret tag information used for authentication of a radio recognition tag and secret group information used for searching for a group to which the secret tag information belongs. Memory; And a hash chain operator for encrypting secret group information and secret tag information based on a hash algorithm to obtain a conversion value.

In addition, the tag authentication apparatus of the RFID system according to the present invention for achieving the above technical problem, DB for storing the information of the radio recognition tag including the secret group information and the secret tag information grouped; A secret group information retrieval unit which searches for a group to which a tag requesting authentication belongs by comparing the values generated by iteratively calculating the secret group information in the DB with a hash chain based on a hash algorithm with a received secret group information conversion value; And recursively calculating secret tag information in the group found by the secret group information retrieval unit into a hash chain and comparing the generated values with the received secret tag information conversion value to search whether the secret tag information of the tag requesting authentication exists in the DB. Secret tag information search unit; includes.

In addition, in order to achieve the above technical problem, the authentication information processing method in a wireless recognition medium of the RFID system according to the present invention, based on a hash algorithm (Hash) is configured in the hash recognition chain to perform the encryption inside the wireless identification tag Obtaining an encrypted conversion value using secret tag information used for authentication of the radio recognition tag and secret group information used to search for a group to which the secret tag information belongs; And updating and storing the secret group information and the secret tag information in a memory of the radio recognition tag.

In addition, the tag authentication method in the RFID system according to the present invention for achieving the above technical problem, the step of storing in advance by grouping the information of the radio recognition tag including the secret group information and secret tag information; A secret group information retrieval step of finding a group to which a tag requesting authentication belongs by comparing the values generated by iteratively calculating the secret group information into a hash chain based on a hash algorithm with a received secret group information conversion value; And a secret tag for retrieving the secret tag information of the tag requesting authentication by comparing the values generated by repeatedly calculating the secret tag information in the group found in the secret group information retrieval step with the received secret tag information converted value. Information retrieval step.

Hereinafter, a tag authentication apparatus and method in an RFID system according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing the basic structure of an RFID system.

Referring to FIG. 1, an RFID system basically includes a wireless recognition medium 110, a reader 120, and a back end database 130.

2 is a diagram illustrating an embodiment of a wireless recognition medium of the RFID system according to the present invention.

Referring to FIG. 2, the wireless recognition medium 210 of the RFID system according to the present invention includes a memory 211 and a hash chain calculator 213.

와 자신의 비밀 태그 정보

를 저장하고 있어야 한다.The memory 211 stores a secret tag information used for authentication of the radio recognition tag and a secret group information used to search for a group to which the secret tag information belongs. Any RFID tag initially has its own secret group information.

And own secret tag information

It should be stored.

번 있었다면, 메모리(211)에 저장된 비밀 그룹 정보와 비밀 태그 정보의 쌍은

가 된다.The secret group information and the secret tag information are updated through repetition of the hash chain in the hash chain operation unit 213 upon interaction between the wireless recognition medium 210 and the reader 120 (see FIG. 1 below). The interaction between the wireless recognition medium 210 and the reader 120

Times, the pair of secret group information and secret tag information stored in the memory 211

Becomes

The secret group information and the secret tag information existing in the wireless recognition medium 210 are updated with the same hash chain number for each interaction with the reader 120 so that the secret group information and the secret tag information have the same hash chain number.

The hash chain operation unit 213 is configured inside the wireless recognition medium 210 based on a hash algorithm, and encrypts secret group information and secret tag information to obtain a conversion value to be returned to the reader 120. Do it. The hash chain calculator 213 will be described in detail with reference to FIG. 3.

와 연산한 후의 값

의 배타적 논리합(exclusive OR)에 의해 계산된 비밀 그룹 정보 변환 값

와, 비밀 태그 정보를 해시 연산하기 전의 값

와 연산한 후의 값

의 배타적 논리합에 의해 계산된 비밀 태그 정보 변환 값

의 쌍

이 된다.The converted value of the hash chain operation unit 213 is a value before hashing secret group information.

The value after computing with

Conversion value of secret group information calculated by exclusive OR of

And the value before hashing the secret tag information.

The value after computing with

Conversion value of secret tag information calculated by exclusive OR of

Pair of

Becomes

3 is a diagram illustrating a basic structure of a hash chain in the hash chain calculating unit.

(303)와 연산한 후의 값

(305)의 배타적 논리합(Exclucive OR, 307)에 의하여 비밀 태그 정보 변환 값

(309)이 얻어진다. 이렇게 암호 변환된 값이 출력되므로 태그와 리더 사이의 통신 내용이 공격자에 의해 도청당하더라도 무선 인식 태그의 보안이 보장된다. 또한 인증에 성공할 때마다 반복된 해시 체인을 통하여 비밀 태그 정보가 갱신되므로, 태그의 프라이버시 문제를 해결할 수 있다.Referring to FIG. 3, a value before hashing secret tag information by hash algorithm H 301.

Value after operation with (303)

Secret tag information conversion value by exclusive OR (307) of 305

309 is obtained. Since the encrypted value is output, even if the communication between the tag and the reader is intercepted by the attacker, the security of the wireless identification tag is guaranteed. In addition, since the secret tag information is updated through the repeated hash chain every time the authentication is successful, the privacy problem of the tag can be solved.

Although FIG. 3 illustrates an example of applying a hash chain to secret tag information, the same hash chain using the same hash algorithm may be applied to secret group information. Therefore, the tag authentication scheme proposed in the present invention has an advantage that it can be applied to a tag having extremely limited resources because only one hash algorithm needs to be implemented.

4 is a diagram illustrating an embodiment of a tag authentication device of an RFID system according to the present invention.

Referring to FIG. 4, the backend database 430 serving as an authentication server includes a DB 431, a secret group information retrieval unit 433, and a secret tag information retrieval unit 435. The backend database 430 records information of all the radio recognition tags to be authenticated, and determines whether to authenticate by searching whether a radio identification tag corresponding to the conversion value received from the reader exists in the DB 431.

Fully examining the information of the wireless identification tags in the backend database 430 consumes a lot of time and system resources. Accordingly, the information of the radio recognition tags is grouped in the DB 431 of the back end database 430 for a quick and efficient search. The DB structure of the back end database 430 will be described in detail with reference to FIG. 5.

The secret group information retrieval unit 433 repeatedly calculates all the secret group information in the DB 431 into a hash chain based on a hash algorithm. The hash chain operation is repeated until it finds the secret group information that produces the received secret group information transform value, that is, compares the values computed by the hash chain with the received secret group information transform value and finds a match. . When the secret group information that produces the received secret group information conversion value is found, the information on the group is sent to the secret tag information search unit 435 to perform the following process for authentication. If the secret group information that produces the secret group information conversion value received in the DB 431 is not found, authentication fails.

The secret group information retrieval unit 433 may limit the number of repetitions of the hash chain by setting a threshold value greater than the number of hash chains having the largest value in the corresponding group as a threshold.

The secret tag information retrieving unit 435 searches for secret tag information in the group found by the secret group information retrieving unit 433. Similarly, the hash chain is repeatedly computed to find secret tag information that produces the received secret tag information conversion value.

The secret tag information retrieval unit 435 may reduce the amount of calculation due to the hash chain operation by retrieving only the information of the radio recognition tags having the hash chain number smaller than the hash chain number found by the secret group information retrieval unit 433.

The secret tag information retrieval unit 435 may reduce the amount of calculation required for the search by using the secret tag information that recently succeeded in the authentication of the radio recognition tag to be searched and the number of hash chains when the recent authentication succeeds. The detailed method is described in FIG.

5 is a diagram illustrating a DB structure of a backend database.

에 따라서 태그들이 여러 그룹으로 나뉘어져 있다. DB 구조에서 각각의 행들은 그에 해당하는 서로 다른 태그 정보를 나타낸다.5, group secret information

Depending on the tags, they are divided into several groups. Each row in the DB structure represents different tag information.

, 최근 인증에 성공한 비밀 태그 정보

, 최근 인증에 성공했을 때의 해시 체인 횟수

및 태그 ID 정보

의 쌍

으로 그룹 내에 저장될 수 있다. Also, in the backend database, for all tags, the information of grouped wireless identification tags is the initial secret tag information.

, Recently verified secret tag information

, The number of hash chains when the last successful authentication

And tag ID information

Pair of

Can be stored in a group.

6 is a diagram illustrating an embodiment of a tag authentication method in an RFID system according to the present invention, and FIG. 7 is a flowchart illustrating the method according to FIG. 6.

6 and 7, a method of processing authentication information in a wireless recognition medium of an RFID system according to the present invention includes obtaining a conversion value of a hash chain and updating secret group information and secret tag information.

번째 상호작용(interaction)이라고 가정할 때, 무선 인식 매체(610)는 비밀 그룹 정보

를 이용하여 수학식 1을 계산하며(S720), 비밀 그룹 정보

를 수학식 2와 같이 갱신한다(S730).The operation method of this embodiment is as follows. First, the reader 620 transmits a start query to the wireless recognition medium 610 (S710). This query sent to the wireless recognition medium 610 with the reader

Assume that the first interaction, the wireless recognition medium 610 is a secret group information

To calculate Equation 1 using (S720), secret group information

Is updated as in Equation 2 (S730).

를 이용하여 수학식 3을 계산하고(S720), 그 후 비밀 태그 정보

를 수학식 4에 의하여 갱신한다(S730).Secret tag information as above

Equation 3 is calculated using (S720), and then the secret tag information

Is updated by Equation 4 (S730).

및 비밀 태그 정보 변환 값

를 리더(620)에게 전송한다(S740). 리더(620)는 수신한

,

값을 백엔드 데이터베이스(630)에게 전달한다(S750). The wireless recognition medium 610 converts the secret group information generated during the above operation.

And secret tag information conversion values

Is transmitted to the reader 620 (S740). Reader 620 receives

,

The value is transferred to the backend database 630 (S750).

The tag authentication method in the RFID system according to the present invention includes a grouping step of a DB of the back-end database 630, a secret group information retrieval step, and a secret tag information retrieval step.

As described above, in the DB of the backend database 630, information of all the radio recognition tags to be authenticated is grouped and stored in advance.

,

값을 가지고 비밀 그룹 정보를 검색한 후(S760), 비밀 태그 정보를 검색한다(S770). Based on this, the backend database 630 receives from the reader 620.

,

After retrieving the secret group information with the value (S760), the secret tag information is retrieved (S770).

를 생성해내는 비밀 그룹 정보가 DB 내에 존재하는 여부를 검색하는 것이다(S760). 해당하는 비밀 그룹 정보가 발견되면 이 비밀 그룹 정보를 가지는 그룹을 선택하여 다음 단계의 검색을 준비한다.In the secret group information retrieval, the backend database 630 repeatedly calculates the secret group information of all the groups in its DB as a hash chain, and converts the received secret group information into a converted value.

It is to search whether or not the secret group information to generate the DB in (S760). If the corresponding secret group information is found, the group having the secret group information is selected to prepare for the next step search.

를 생성해내는 비밀 태그 정보가 상기 DB 내에 존재하는지 여부를 검색하는 것이다(S770).The secret tag information retrieval repeats the hash chain calculation of all secret tag information in the previously selected group.

It is to search whether the secret tag information for generating the present in the DB (S770).

The search for the secret group information and the search method for the secret tag information will be described in detail with reference to FIGS. 6 and 7, respectively.

값을 생성해내는 태그의 비밀 정보를 담고 있는 행를 찾은 경우, 그 행에서 최근 인증에 성공한 비밀 태그 정보

를

로 갱신하고, 또한 이에 대응하는 해시 체인의 횟수

을

로 갱신한다(S780). 그 후 백엔드 데이터베이스(630)는 무선 인식 매체(610)를 인증한 것으로 간주하고 리더(620)에게 찾은 태그 ID 정보를 전송한다(S791).Backend database 630 finally

If you find a row that contains the secret information of the tag that generates the value, the secret tag information that successfully authenticated in that row.

To

And the number of hash chains corresponding to

of

Update to (S780). Thereafter, the backend database 630 regards the wireless recognition medium 610 as authenticated and transmits the tag ID information found to the reader 620 (S791).

내의 모든 태그들에 대해서

을 생성해내는 태그가 존재하지 않는 경우는 인증 실패로 간주하고 리더(110)에게 에러를 전송한다(S792).Failed to retrieve secret group information or found group

For all tags in

If there is no tag to generate the authentication is considered an authentication failure and transmits an error to the reader (110) (S792).

In the tag authentication method according to the present embodiment as in the embodiment of the wireless authentication medium according to the present invention described above, the secret group information and the secret tag information are interacted with the radio recognition medium 610 and the reader 620. The hash can be updated through iteration of the hash chain. In addition, the secret group information and the secret tag information may have the same hash chain number.

In the tag authentication method in this embodiment as in the embodiment of the wireless authentication medium according to the present invention described above, the converted value of the hash chain is an exclusive logical sum of the value before and after the hash operation of the secret group information. and a secret group information converted value calculated by exclusive OR) and a secret tag information converted value calculated by an exclusive OR of the value before the hash operation and the value after the hash tag information.

In the tag authentication method according to the present embodiment, as in the above-described embodiment of the wireless authentication medium according to the present invention, the backend for receiving the converted value of the hash chain from the reader 620 and searching for the existence of a corresponding radio recognition tag. The information on the radio recognition tags may be grouped in the back-end database 630. In addition, the information of the grouped wireless identification tags may be stored in the group as a pair of initial secret tag information, secret tag information that has recently been successfully authenticated, hash chain count when tagging has been successfully authenticated, and tag ID information.

8 is a flowchart illustrating in more detail the secret group information retrieval step S760 of FIG.

를 전달받는다(S761). 백엔드 데이터베이스는 자신의 DB에 존재하는 모든 비밀 그룹 정보

에 대하여,

를 생성시키는

을 찾기 위해 수학식 5에 의해

를 계산하고(S762),

와

가 일치하는지 검사한다(S763). 이것은 무선 인증 태그의 해시 체인과 동일한 해시 체인을 백엔드 데이터베이스에서 반복 계산하여 전수 조사하는 것에 해당한다. 8, first, the back-end database converts secret group information from the reader.

Received (S761). The backend database has all the secret group information present in its DB

about,

Generating

By Equation 5 to find

(S762),

Wow

Is checked (S763). This corresponds to a full recursion of the same hash chain in the backend database as the hash chain of the wireless authentication tag.

Preferably, by setting a threshold for the number of iterations of the hash chain, it is possible to restrict the hash chain operation to repeat within a range not exceeding the threshold (S764). The threshold is set larger than the number of hash chains with the largest value in the group. Thresholds can be set dynamically depending on the flexibility of the system.

If the back-end database finds the corresponding secret group information in its DB, the back-end database returns the secret group information and the hash chain count of the group to the next step (S765).

If the corresponding secret group information is not found in the DB of the back-end database, it is regarded as an authentication failure and an error is transmitted to the reader (S766).

FIG. 9 is a flowchart illustrating the secret tag information retrieval step S770 shown in FIG. 7 in more detail.

와, 전 단계에서 찾은 비밀 그룹 정보

에 해당하는 특정 그룹 및

값이

가 될 때까지의 체인의 횟수

를 입력받는다(S771). 이번에는 해당 그룹을 선택하여(S772) 그룹 내에 존재하는 태그들을 조사하게 된다. 여기서 중요한 것은 무선 인식 태그 내에 존재하는 그룹 비밀 정보

와 비밀 태그 정보

는 리더와의 상호작용 때마다 동일한 해시 체인 횟수로 갱신됐다는 것이다. 따라서, 위에서 계산한 해시 체인의 횟수

를 이용하여 전 단계에서 찾은 그룹

내의 DB 에서 최근 인증에 성공한 해시 체인 횟수를 저장한 열을 비교하여, 그 중

보다 작은 해시 체인 횟수를 저장하고 있는 행에서만 비밀 태그 정보 변환 값

을 생성해내는 비밀 태그 정보를 찾으면 된다(S773).Referring to FIG. 9, first, a secret tag information converted value received from a reader

Wow, the secret group information you found in the previous step

Specific groups corresponding to

Value is

The number of chains until

To receive the input (S771). This time, the group is selected (S772) and the tags existing in the group are examined. What's important here is the group secret in the radio tag.

And secret tag information

Is updated with the same hash chain count for each interaction with the leader. Therefore, the number of hash chains calculated above

Use the group found in the previous step

Compares the column that stores the number of hash chains that have been successfully authenticated in DB within

Secret tag information conversion value only on rows that contain fewer hash chains

Find the secret tag information to generate the (S773).

을 생성해내는 비밀 태그 정보를 검색하는데 있어서 검색하려는 무선 인식 태그의 최근 인증에 성공한 비밀 태그 정보와 최근 인증에 성공했을 때의 해시 체인 횟수를 이용하여 상기 해시 체인을 계산할 수 있다. 즉, 백엔드 데이터베이스의 DB에는 최근 인증에 성공했을 때의 갱신된 비밀 정보

를 저장하고 있으며 그와 동시에 최근 인증에 성공했을 때의 해시 체인 횟수

을 저장하고 있다. 따라서

를 계산하기 위해

을 가지고 처음부터

번 해시 체인을 계산할 필요 없이 저장되어 있는

을 가지고 수학식 6과 같이

번 해쉬 체인을 계산하여 빠른 연산을 수행한다(S774).Secret tag information conversion value

In retrieving the secret tag information for generating the Hash chain, the hash chain may be calculated using the secret tag information of the successful authentication of the wireless identification tag to be searched and the number of hash chains of the successful authentication. In other words, the DB of the back-end database has updated secret information when the latest authentication is successful.

At the same time as the number of hash chains when the last successful authentication

Is saving. therefore

To calculate

From the beginning

Stored without having to compute the hash chain

With Equation 6

The fast hash chain is calculated to perform a fast operation (S774).

와 리더로부터 전달받은 비밀 태그 정보 변환 값 가 일치하는지 검사한다(S775).Then

Conversion value of secret tag information received from reader and reader Check whether the match (S775).

를 생성하는 비밀 태그 정보를 찾으면 인증에 성공한 것으로 간주하고 해당 태그 ID를 리턴한다(S776).The backend database converts secret tag information from its group

If it finds the secret tag information to generate a deemed successful authentication and returns the corresponding tag ID (S776).

를 생성하는 비밀 태그 정보를 찾지 못하면 인증 실패로 간주하고 리더에게 에러를 전송한다(S777).If the secret tag information conversion value in the group

If no secret tag information is generated, it is regarded as an authentication failure and an error is transmitted to the reader (S777).

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which may also be implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown not in the above description but in the claims, and all differences within the equivalent and equivalent scope will be construed as being included in the present invention.

According to the present invention, while maintaining the security function of the existing techniques, while protecting the tag privacy, which is an essential element for the security service in the RFID system environment, the amount of calculation to find the tag ID stored in the backend database is greatly reduced. . Therefore, it is possible to quickly and efficiently wireless tag authentication and to build an authentication system suitable for a large capacity RFID system.

In addition, according to the present invention, since only one hash algorithm may be implemented in the radio recognition tag, system resources may be efficiently used. Therefore, there is an advantage that can be applied to the radio recognition tag having an extremely limited resource.

Claims (19)

A memory for storing secret tag information used for authentication of the radio recognition tag and secret group information used for searching for a group to which the secret tag information belongs; And And a hash chain calculator configured to obtain a conversion value by encrypting the secret group information and the secret tag information based on a hash algorithm. 2. The method of claim 1, And the secret group information and the secret tag information are updated through repetition of a hash chain upon interaction between the radio recognition tag and a reader receiving the conversion value. The method of claim 1, And the secret group information and the secret tag information have the same hash chain number. The method of claim 1, The converted value is calculated by calculating a secret group information converted value by an exclusive OR of a value before and after hashing the secret group information, and a value before hashing the secret tag information. And a pair of secret tag information conversion values calculated by an exclusive OR of the following values. A DB in which information on wireless identification tags including secret group information and secret tag information is grouped and stored; A secret group information retrieval unit for searching for a group to which a tag requesting authentication belongs, by comparing the generated secret group information in the DB with a hash chain based on a hash algorithm and comparing the values generated with the received secret group information conversion value; And By comparing the values generated by iteratively calculating the secret tag information in the group found by the secret group information retrieval with the hash chain and receiving the converted secret tag information converted value, whether the secret tag information of the tag requesting authentication exists in the DB. The tag authentication apparatus of the RFID system comprising a; secret tag information search unit for searching. The method of claim 5, The information of the grouped wireless identification tags is stored in the group as a pair of initial secret tag information, secret tag information that recently succeeded in authentication, number of hash chains when successful in recent authentication, and tag ID information. Tag authentication device. The method of claim 5, The secret group information retrieval unit is configured to search by limiting the number of repetitions of the hash chain by setting a value greater than the number of hash chains having the largest value in the corresponding group as a threshold. Tag authentication device. The method of claim 5, The secret tag information retrieval unit, the tag authentication apparatus of the RFID system, characterized in that for searching only the information of the radio recognition tags having a hash chain number less than the number of hash chains found by the secret group information retrieval unit. The method of claim 5, The secret tag information retrieval unit is a tag authentication apparatus of the system, characterized in that the search using the number of hash chains when the last successful authentication and the secret tag information of the wireless identification tag to be searched. Based on a hash algorithm, a hash chain configured inside a wireless identification tag and performing encryption encrypts secret tag information used for authentication of the wireless identification tag and secret group information used to search for a group to which the secret tag information belongs. Obtaining an encrypted conversion value using the method; And And updating and storing the secret group information and the secret tag information in a memory of the radio recognition tag. The method of claim 10, The secret group information and the secret tag information is updated through the repetition of the hash chain upon interaction between the radio recognition tag and the reader receiving the conversion value. How to process authentication information. The method of claim 10, And the secret group information and the secret tag information have the same hash chain number. The method of claim 10, The converted value is calculated by calculating a secret group information converted value by an exclusive OR of a value before and after hashing the secret group information, and a value before hashing the secret tag information. A method of processing authentication information in a radio recognition medium of an RFID system, characterized in that it is a pair of secret tag information conversion values calculated by exclusive OR of later values. Grouping and storing the information of the radio recognition tags including the secret group information and the secret tag information in advance; A secret group information retrieval step of finding a group to which a tag requesting authentication belongs by comparing the values generated by repeatedly calculating the secret group information with a hash chain based on a hash algorithm with a received secret group information conversion value; And A secret for searching for the existence of secret tag information of the tag requesting authentication by comparing the values generated by repeatedly calculating the secret tag information in the group found in the secret group information retrieval with the hash chain and receiving the converted secret tag information converted value Tag information retrieval step; Tag authentication method of the RFID system comprising a. The method of claim 14, In the RFID system, the grouped information of the wireless identification tags is stored in the group as a pair of initial secret tag information, recently successful secret tag information, hash chain number when a recent authentication succeeds, and tag ID information. Tag verification method. The method of claim 14, In the secret group information retrieval step, the number of repetitions of the hash chain is limited by setting a threshold value greater than the number of hash chains having the largest value in the corresponding group as a threshold. Tag verification method. The method of claim 14, In the secret tag information retrieval step, the tag authentication method in the RFID system, characterized in that for retrieving only the information of the radio recognition tags having a hash chain number less than the number of hash chains generated in the secret group information retrieval step. The method of claim 14, In the secret tag information retrieval step, the hash chain is calculated using the secret tag information of the successful authentication of the wireless identification tag to be searched and the number of hash chains of the successful authentication. Authentication method. A computer-readable recording medium having recorded thereon a program for executing the method according to any one of claims 10 to 18.

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