KR100896342B1 - Money embedding RFID tag, Method for encrypting money embedding RFID tag, Method for verifying counterfeited money embedding RFID tag, User tracking method for money embedding RFID tag and Record medium thereof - Google Patents

Abstract

Disclosed are a currency with an RFID tag, a method for encrypting a currency with an RFID tag, a method for verifying and forgery of a currency with an RFID tag, a user tracking method for a currency with an RFID tag, and a recording medium recording the same.

According to the present invention, a RFID-embedded currency includes a first ciphertext storage unit for storing a first ciphertext randomly generated according to a tag key stored in advance in a tag, and a counter unit for updating a counter value whenever a query of a reader occurs. A second ciphertext generator configured to generate a second ciphertext by using the first ciphertext updated at the counter and randomly selected for each currency and storing a random number value as an input value of a hash function; and the generated second ciphertext And a currency embedded with an RFID tag including a transmitter for transmitting the counter value whenever a query of a reader occurs, and a memory for storing information about the currency.

According to the present invention, it is possible to identify whether the forgery of the currency through the reader using the RFID reader, not the naked eye through the RFID tag embedded in the currency, the general public can easily determine whether the forgery of the currency, the RFID The use of tags has the effect of protecting the privacy of monetary holders.

Description

Money with RFID tag, encryption method with RFID tag, method for verifying forgery of money with RFID tag, user tracking method with RFID tag embedded, and recording medium {Money embedding RFID tag, Method for encrypting money embedding RFID tag, Method for verifying counterfeited money embedding RFID tag, User tracking method for money embedding RFID tag and Record medium according}

1 illustrates a currency in which an RFID tag is embedded according to an embodiment of the present invention.

2 is a flowchart illustrating a method of encrypting money with an RFID tag according to another embodiment of the present invention.

3 is a flowchart illustrating a method for verifying forgery and alteration of money with an RFID tag according to another embodiment of the present invention.

4 is a flowchart illustrating a user tracking method of money with an RFID tag according to another embodiment of the present invention.

The present invention relates to RF communication, in particular, it is possible to identify the forgery and modulation of the currency information in the currency embedded RFID tag, as well as to protect the privacy of the user who owns the currency RFID embedded currency, The present invention relates to a method for encrypting a currency with an RFID tag, a method for verifying and forgery of a currency with an RFID tag, a user tracking method for a currency with an RFID tag, and a recording medium recording the same.

Radio Frequency Identification (RFID) system is an automatic recognition technology that reads information of an object from a distance using RF communication. This system is attracting attention as a system that will replace the barcode system because it can read the information of the object quickly without physical contact. Recently, this system has been used in part in logistics systems, traffic management systems, animal management systems and the like.

When an RFID reader (hereinafter referred to as a "leader") sends a query to an RFID tag, the tag sends its information to the reader, which is sent to a database. In this way, a service provider can easily obtain information of a tagged consumer anytime, anywhere, and provide various convenient services to such a consumer. However, since tags and readers communicate on the Insecure Channel, an attacker can eavesdrop on messages that are sent and can expose sensitive information such as credit, purchase patterns, and health information to consumers. Can be. The attacker can also analyze this message to track the location of the consumer who has the tag.

One of the biggest features of RFID systems is that tags have limited resources. Therefore, there is a need to protect the privacy of consumers while reducing the amount of computation of tags. There are physical and cryptographic methods for this purpose. Cryptographic methods are classified into a method using a hash function and a method of re-encryption.

Early inventions used physical techniques such as Kill Command. Kill Command is a method of clearing tag information from a purchased product and not reactivating it.

The cryptographic method is the authentication protocol technique using a hash function. 'Hash Lock' can hide ID of tag by using one-way property, which is a characteristic of hash function, but location information is exposed. 'Hash-Chain' provides forward security while hiding location information, but to check tag information, database must execute hash operation as many as maximum number of tags. The protocol is also vulnerable to replay attacks and spoofing attacks.

Another cryptographic method is a re-encryption technique, which periodically re-encrypts tag information using an external device using a public key or a symmetric key. This technique prevents exposure of tag information through encryption and hides location information of tag users through re-encryption. However, since the tag always responds the same value to the reader's query until the next re-encryption step is executed, it is necessary to frequently re-encrypt with the external device to hide the location information.

Considerations for privacy protection in RFID tag lead systems include: There are various vulnerabilities in tag reader system (RFID system) such as message eavesdropping, analysis, alteration, etc. Using these vulnerabilities, an adversary would try to expose sensitive information on a tag and track the location of the tag to violate the privacy of the consumer with the tag.

First is Information Leakage. In a ubiquitous environment, most people will have several informational tags on their bodies. Some of the information in the tag may be very personal and not desired to be exposed to others. For example, most people don't want their name, expensive product, or book name exposed to others. If a tag with such sensitive information is widely used, the tag will send such information to a reader who does not know it is authenticated through an incomplete channel. Therefore, the tag's information is easily exposed to the attacker, and the privacy of the tag user will be violated.

Second is traceability. When a tag sends a response to a reader's query, if the attacker can distinguish whether or not the response is from the target tag, the tag's location can be tracked. Also, even if the attacker does not understand the content of the tag response, if the attacker can create a link between the target tag and the response, the attacker can track the target tag's location. In other words, the attacker could track the location of the target consumer with the tag.

In this regard, when looking at the financial transaction method using conventional banknotes and securities, first of all, when making banknotes and securities, various patterns and patterns are formed in order to prevent counterfeiting and duplication, and a special pattern that is exposed by light is revealed. It may be configured. In the case of banknotes in particular, a very fine mark, which is identified by a magnifying glass, may be inserted into the pattern.

The banknotes and securities produced as described above are visually checked by the general public and traded with each other. Most financial institutions also identify with the naked eye and perform deposit and withdrawal using the corresponding trading account.

Such existing banknotes and securities systems, such as a color copying machine, a computer scanner, an inkjet printer, an offset printing machine can be easily forged by various computer-related devices, and financial accidents are frequently caused by this.

In fact, as can be seen in the recent case of counterfeit bills, there is a serious problem that conventional banknotes, checks and securities can be easily forged by anyone using computer-related devices. There is this.

First of all, no matter how many different marks and colors are inserted in order to prevent forgery, forgery and duplication technology has recently advanced considerably, so that forgery or duplication of fine color copiers, computer scanners, offset presses and inkjet printers can It is possible that even adolescents can make counterfeit bills.

In addition, since the counterfeit or duplication must be checked with the naked eye, especially in a night-time transaction, it is not easy for the public to discern the use of the forgery or duplication. It occurs frequently at night.

In addition, even the finely crafted banknotes and securities, it is difficult to distinguish whether the general public is real or a counterfeit. This is often the case even when ordinary people don't even know what special signs and pictures are inserted into real bills, and it's hard to tell the tricks of counterfeit bills, checks and securities on the deal, In some cases, looking directly at the authenticity of counterfeiting gives the impression of distrusting the customer, making it difficult to identify forgery in a transaction.

That is, the conventional method of checking forgery of money is difficult to check forgery of money by using a method of checking forgery of money by the naked eye, and furthermore, the money with RFID tag detects forgery of money. Although it is possible to read the encrypted information of the currency, other third parties can obtain the secret value of the encrypted information and use the information to find out the user's location information. There is a problem that can be.

Accordingly, the first technical problem to be achieved by the present invention is not only to detect forgery and alteration of money by using the RFID tag embedded money, but also by updating the cipher text transmitted from the money in the tag embedded in the money. It is to provide money with RFID tag that can prevent privacy invasion.

In addition, a second technical problem to be achieved by the present invention is to provide a method for encrypting a currency with an RFID tag using a currency with the RFID tag.

In addition, a third technical problem to be achieved by the present invention is to provide a method for verifying forgery and alteration of money embedded with an RFID tag using the money with the RFID tag embedded therein.

In addition, the fourth technical problem to be achieved by the present invention is to provide a user tracking method of the RFID tag embedded currency using the RFID tag embedded currency.

In addition, the fifth technical problem to be achieved by the present invention can be read by a computer recording the encryption method of the currency embedded with the RFID tag, the forgery verification method of the currency embedded with the RFID tag, and the user tracking method of the currency embedded with the RFID tag To provide a recording medium.

The present invention to achieve the first technical problem,

A first ciphertext storage unit for storing a first ciphertext randomly generated according to a tag key previously stored in a tag, a counter unit for updating a counter value each time a query of a reader occurs, and updating the first ciphertext at the counter unit A second ciphertext generation unit for generating a second ciphertext using a randomly selected counter value and a randomly stored value as a hash function as an input value of the hash function, whenever the query of the reader occurs using the generated second ciphertext and the counter value; Provides a currency embedded with an RFID tag, including a transmitting unit for transmitting, and a memory for storing information about the currency.

The present invention to achieve the second technical problem,

Generating a signature of each currency by a signature algorithm based on a monetary unit of each currency to which a unique number has been assigned; a unique value of the currency, the monetary unit, the generated signature, and a verification value stored in a tag of the currency Generating a first ciphertext by using the first ciphertext, generating a randomized second ciphertext using the first ciphertext from the tag of the currency, and when the user withdraws a currency storing the generated second ciphertext. The method provides a method for encrypting a currency with an RFID tag, which comprises storing the information of the withdrawn money and the information of the withdrawn user in a database of a central server.

The present invention to achieve the third technical problem,

Generating a first ciphertext using a unique number of a currency, a currency unit, a signature generated by a signature algorithm when issuing the currency, a tag key randomly generated and stored in a tag of the currency, and a public key publicly disclosed in advance; 1 generating a randomized second cipher text using a cipher text and storing the second cipher text in a tag of the currency; when the RFID reader queries the tag, the unique number of the currency stored in the optical memory area of the tag, the signature, Transmitting a randomly selected random number value for each currency, a verification value generated by a tag key and a public key of the currency, and a counter value which updates its own value according to a query of the second cryptogram and a reader to the reader; And a hash function using the second ciphertext transmitted from the reader as an exclusive logical sum of the counter value and the random number as an input value. W comprising the steps of: generating a first cipher text, and provides a forgery verification of an RFID tag is built currency comprises the step to determine whether the forgery of the currency using the first cipher the created.

The present invention to achieve the fourth technical problem,

Generating a first cipher text using a unique number of a currency, a currency unit, a signature generated by a signature algorithm when issuing the currency, a public key and a tag key of the currency, and a second randomized second text using the first cipher text. Generating a cipher text and storing it in a tag of the currency, When an RFID reader queries a tag, a unique number of the optical memory area of the tag, the signature, a random number randomly selected for each currency, the verification value stored in the currency And transmitting a counter value which updates a value by itself according to a query of the second cipher text and a reader to the reader, and extracts an exclusive logical sum of the counter value and the random number from the transmitted second cipher text. A first cipher text is generated using a hash function, and a verification value stored in the optical memory area is generated from the first cipher text. Checking whether the forgery of the lung is altered, when the currency is forged, the reader transmits the second cipher text, the counter value, and the random number value to a trust authority, and the trust authority uses the hash function. Calculating a cipher text, using a secret key of the trust authority from the first cipher text, calculating a unique number and a signature of the bill, and tracking a user of the money according to the unique number; Provides a user tracking method of embedded currency.

The present invention to achieve the fifth technical problem,

The present invention provides a recording medium recording the RFID tag-embedded money, the encryption method of the RFID-embedded money, the forgery verification method of the RFID-embedded money, and the user tracking method of the RFID-embedded money.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, embodiments of the present invention illustrated below may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the invention are provided to more fully illustrate the invention to those skilled in the art.

1 illustrates a currency in which an RFID tag is embedded according to an embodiment of the present invention.

Referring to FIG. 1, the RFID tag 100 of the currency includes a first cipher text storage unit 110, a counter unit 120, a second cipher text generation unit 130, a transmission unit 140, and a memory 150. It is composed.

First, the first cipher text storage unit 110 stores the first cipher text randomly generated according to the tag key stored in advance in the tag.

In fact, the information stored in money at the time of money issuance is generated based on the public key of a specific trust authority. Based on this, if the forgery of money occurs, the information of the forgery money can be found together with the central bank, which plays a role of supplying money without physical contact with the forgery.

,

을 선택하고,

에서 위수(order)가

인 부분군(subgroup), G의 생성자

를 선택한다.In more detail, trust institutions are two prime numbers

,

Select it,

The order in

Subgroup, constructor of G

Select.

를

에서 랜덤하게 생성하여

의 연산결과에 따라 공개키

를 연산한다. The trust authority then generates a key for use in encrypting the message. This is a secret key

To

Randomly generated from

Public key depending on the result of

Calculate

를 공개하고, 상기 비밀키

를 비밀로 유지하며, 해쉬 함수

를 공개한다.Accordingly, the public key

Reveal the secret key

Secrets and hash functions

To the public.

Practically, the central bank can issue a currency with a tag embedded in it, create and store a signature for each currency to prevent forgery of the currency, and store the data in encrypted form to provide confidentiality of the value transmitted by the tag. Save it.

Specifically, the central bank generates a pair of signing keys SK _B and PK _B. Then, the central bank assigns a unique number (S _i ) to each currency (i), and generates a signature (∑ _i ) together with the currency unit (D _i ).

The equation for obtaining the signature is shown in Equation 1 below.

In Equation 1, Sig means a public key signature algorithm, and in detail, may mean an RSA signature algorithm, SK _B means a signature key, S _i indicates a unique number, and D _i indicates a monetary unit. Indicates.

In addition, the central bank may use the following values to protect the privacy of money users.

First, the hash function h is a function that outputs a value of a certain length to an input value of an arbitrary length. The hash function h generates a value transmitted by each tag i differently.

)은 해수 함수에 입력값으로 사용되며, 태그가 매번 다른 값을 생성하기 위해 리더의 질의에 대하여 자체적으로 값을 증가시킨다.Counter value (

) Is used as input to the seawater function, and the tag increments itself for the reader's query to generate a different value each time.

)은 태그가 리더로 전송한 메시지의 도청자라도 태그에 저장된 값을 알 수 없도록 하기 위해 사용되며, 화폐마다 랜덤하게 선택되어 저장된다.And a random value (

) Is used to prevent the eavesdropper of the message sent by the tag to the reader, but to know the value stored in the tag.

Meanwhile, the central bank generates the first cipher text using the public key of the trusting authority to ensure the confidentiality of the data to be stored in the currency.

에서 랜덤하게 생성하여, 이를 기반으로 상기 제 1 암호문을 생성하고 상기 화폐의 태그에 내장된 제 1 암호문 저장부에 저장한다.This means that K _i , the tag key of tag (i) of each currency (i),

Randomly generates a, and generates the first cipher text based on the first cipher text and stores the first cipher text in a first cipher text storage unit embedded in a tag of the currency.

Meanwhile, the first cipher text is shown in Equation 2 below.

에서

는 공개키를 의미하고,

는 각 화폐(i)의 태그(i)의 태그키을 의미하고,

는

에서 위수(order)가

인 부분군(subgroup), G의 생성자를 의미한다.In Equation 2 above, S _i represents a unique number of money, ∑ _i means a signature generated by a public key signature algorithm, Di means a currency unit of each currency,

in

Means public key,

Means a tag key of tag (i) of each currency (i),

Is

The order in

Subgroup, which means the constructor of G.

On the other hand, the counter 120 updates the counter value whenever a query of the reader occurs. As described above, the tag increments itself with respect to the reader's query in order to always generate a different value each time the reader has a query.

Thereby, the basis for preventing the infringement of the privacy of the money holders by updating the cryptography of the money.

In addition, the second cipher text generation unit 130 hashes the first cipher text stored in the first cipher text storage unit 110 and a randomly selected counter value updated by the counter unit 120 and the random number stored for each currency. The second ciphertext is generated as the input value of the function.

The second cipher text is generated by Equation 3 below.

는 제 2 암호문을 의미하며,

는 제 1 암호문 저장부에 저장된 제 1 암호문을 의미하고,

는 해쉬 함수에 입력값으로 사용되며, 태그가 매번 다른 값을 생성하기 위해 리더의 질의에 대하여 자체적으로 값을 증가시키는 카운터값을 의미하고,

는 각 화폐마다 랜덤하게 생성되어 저장된 난수값을 의미한다.In Equation 3

Means the second cipher text,

Means the first cipher text stored in the first cipher text storage unit,

Is used as input value to hash function, and it means counter value that tag increments itself for query of reader to generate different value every time.

Is a randomly generated random value for each currency.

That is, the second cipher text is the input value of the hash function, and the exclusive logical sum of the counter value and the random number that increases the value itself for the query of the reader in order to generate a different value every time. Compute the exclusive OR of the first ciphertext to compute the second ciphertext.

The transmitter 140 transmits the generated second cipher text and the counter value to the reader each time a query of the reader occurs.

The tag also includes a memory 150 that stores information about the currency.

In more detail, the memory may include an optical memory area 151, a transfer memory area 152, and an internal memory area 153.

The optical memory area 151 stores a unique number of the currency, a signature and a verification value generated based on the unique number and the currency unit of the currency. The verification value may be generated by a tag key stored in the tag and a public key publicly disclosed in advance.

The transmission memory area 152 stores the second cipher text generated by the second cipher text generator and the counter value of the counter, and transmits the second cipher text and the counter value to the transmitter when an inquiry of the reader occurs. do.

The internal memory area 153 stores the random number value and the hash function.

2 is a flowchart illustrating a method of encrypting money with an RFID tag according to another embodiment of the present invention.

Referring to FIG. 2, first, a signature of each currency is generated by a signature algorithm based on a monetary unit of each currency assigned a unique number (step 210).

As described above, the signature is generated by using a signature algorithm according to a signature key generated by the central bank, a unique number assigned to each currency, and a currency unit. The signature generation method by the signature algorithm may be generated by Equation 1 above.

Next, a first cipher text is generated using the unique number of the currency, the currency unit, the generated signature, a tag key stored in a tag of the currency, and a public key publicly disclosed in advance (step 220).

In order to prevent forgery of money, a signature is generated and stored for each currency, and data is stored in an encrypted form to provide confidentiality of the value transmitted by the tag.

Specifically, the central bank generates a pair of signing keys SK _B and PK _B , and the central bank assigns a unique number S _{i to} each currency ( _i ) and signs it with the monetary unit (D _i ). Create (∑ _i ).

에서 랜덤하게 생성하여, 상기 태그키, 공개키, 상기 화폐의 고유번호, 상기 화폐단위, 상기 생성된 서명을 이용하여 제 1 암호문을 생성하게 되며, 제 1 암호문은 상기의 수학식 2에 의하여 생성될 수 있다.Then, K _i which is a tag key of tag (i) of each currency (i)

Generate randomly from the tag key, public key, the unique number of the currency, the currency unit, using the generated signature to generate a first cipher text, the first cipher text is generated by the equation (2) Can be.

In operation 230, a randomized second cryptogram is generated using the first cryptogram in the tag of the currency.

The second cipher text, as described above, generates a second cipher text by using the updated cipher text as the input value of the hash function using the updated counter value and randomly selected random currency for each currency as described above. The second cipher text may be generated by Equation 3 above.

That is, the second cipher text is the input value of the hash function, and the exclusive logical sum of the counter value and the random number that increases the value itself for the query of the reader in order to generate a different value every time. Compute the exclusive OR of the first ciphertext to compute the second ciphertext.

Finally, when the user withdraws the currency in which the generated second cipher text is stored, the information of the withdrawn currency and the information of the withdrawn user are stored in a bank database (step 240).

When a problem arises with the use of money, it obtains the user's information related to the money, and not only identifies the counterfeit money but also uses the unique number of the forged money to search the user's information using the forged money. Will be sent to the database.

3 is a flowchart illustrating a method for verifying forgery and alteration of money with an RFID tag according to another embodiment of the present invention.

Referring to FIG. 3, a first cipher text is generated using a unique number of a currency, a currency unit, a signature generated by a signature algorithm when issuing money, a public key publicly disclosed, and a tag key stored in a tag (step 310). .

Next, a second randomized cipher text is generated using the first cipher text and stored in a tag of the currency (step 320).

Since this overlaps with the above description, a detailed description thereof will be omitted.

Then, the RFID reader inquires the tag, according to the unique number of the currency stored in the optical memory area of the tag, the signature, a randomly preselected random number for each currency, the second cryptogram and the query of the reader. The counter value is updated to transmit its value to the reader (step 330).

, 서명인 ∑_i, 화폐마다 랜덤하게 미리 선택된 난수값인

, 태그의 전송 메모리 영역에 저장된 제 2 암호문인

및 카운터 값인

를 전송한다.This means that when a reader queries a tag, the tag embedded in the currency is the unique number of the currency stored in the optical memory area in response to the reader.

, The signature ∑ _i , the random random preselected random value for each currency,

, The second ciphertext stored in the transmission memory area of the tag.

And the counter value

Send it.

In operation 340, the reader generates a first cipher text using a hash function that uses an exclusive logical sum of the counter value and a random number as the input value.

를 이용하여 상기 카운터 값 및 난수값의 배타적 논리합을 입력값으로 하여 해쉬함수의 결과값을 연산하고, 상기 해쉬함수의 결과값과 제 2 암호문에 논리적 배타 합을 수행함으로써 제 1 암호문을 생성한다.This process is a hash function

By using the exclusive logical sum of the counter value and the random number as an input value to calculate the result of the hash function, and generates a first cipher text by performing a logical exclusive sum of the result of the hash function and the second cipher text.

를 이용하여

를 생성하고, 이 값과

값에 배타적 논리합을 수행하여 제 1 암호문인

값을 생성한다.In detail, the hash function

Using

Is generated, and this value

Perform an exclusive OR on the value

Create a value.

 Finally, it is checked whether the currency is forged using the generated first cipher text (step 350).

This may determine whether the currency is forged by the public key obtained from the first cipher text and the tag key stored in the tag of the currency.

In practice, currency tags increment the counter value each time a query is received from the reader. If currency i communicates with reader j, the tag of currency performs the following process.

이 된다. 상기 카운터 값과 난수값인

를 해쉬함수의 입력값으로 하여

를 생성한다. 그러면,

를 이용하여 j번째 응답으로

값을 생성하여 리더에 전송한다.First, the currency tag increments the counter value each time a query is received from the reader. For jth communication, the counter value is

Becomes The counter value and the random number

As the input value of the hash function

Create then,

To the j response using

Create a value and send it to the reader.

In the present invention, in order to confirm the forgery of money, a verification value is calculated from the public key obtained from the first cipher text and the tag key of the money, and whether the forgery of the money is checked using the calculated verification value.

라하고, 화폐의 태그키를

라 하고, 이로부터 연산되는 검증값은

라 하면,

=

라고 할 때, 상기 검증값인

값을 이용하여 하기의 수학식 4의 성립여부를 확인한다. That is, the public key obtained from the first cipher text

And tag tag of money

The verification value calculated from

Say,

=

Is the verification value

By using the value it is confirmed whether the following equation (4).

If Equation 4 does not hold, it is determined that a forgery of information of money has occurred.

4 is a flowchart illustrating a user tracking method of money with an RFID tag according to another embodiment of the present invention.

Referring to FIG. 4, first, a unique number of a currency, the monetary unit, and a signing key are generated in the currency when the currency is issued, and a unique number is assigned to each currency to generate a signature based on the currency unit of the currency. Based on the signature, the first cipher text is generated using the public key publicly disclosed (step 410).

Next, a second randomized cipher text is generated using the first cipher text and stored in a tag of the currency (step 420).

Next, when the RFID reader queries the tag, the RFID reader updates its own value according to the unique number of the optical memory area of the tag, the signature, a randomly selected random value for each currency, the second cipher text and the query of the reader. The counter value is transmitted to the reader (S430).

In operation 440, the reader generates a first ciphertext using a hash function that uses an exclusive logical sum of the counter value and the random number as the input second ciphertext.

In operation 450, the currency is forged or not by using a verification value calculated by a public key and a tag key stored in a tag.

The process of generating the first cipher text (step 410) or the step of checking whether the currency is forged (step 450) is the same as described above, and thus duplicated details will be avoided.

Then, when the currency is forged, the reader transmits the second cipher text, the counter value and the random number value to the trust authority, and the trust authority generates the first cipher text using the hash function ( 460 courses).

That is, a second cryptographic text, which is a value transmitted in a trust period, a randomly selected random value for each currency, and a signing key for the currency when a currency is issued, and a unique number is assigned to each currency based on the currency unit of the currency. A first cipher text is generated from the second cipher text using the signature generated by the signature algorithm.

값을 연산하고, 상기 연산된 값과 제 2 암호문에 배타적 논리합을 수행함으로써 제 1 암호문

을 생성한다.This is done using a hash function

Calculating a value and performing an exclusive OR on the calculated value and the second ciphertext.

Create

Finally, the unique number and signature of the currency are calculated using the first cipher text and the secret key, and the user of the currency according to the unique number is tracked (step 470).

)를 이용하여 화폐의 고유번호와 서명을 구하는 과정이다.This means that the encryption key (

) Is the process of obtaining the unique number and signature of money.

The unique number and signature of the currency can be obtained by Equation 5 below.

와

를 알 수 있으므로, 화폐의 서명(

)과 화폐 단위(

)를 기반으로 위변조된 화폐의 고유번호를 알아낼 수 있다.Looking at Equation 5, the encryption key of the trusted authority, the first cipher

Wow

As you can see, the signature of the currency (

) And monetary units (

), You can find the unique number of the forged currency.

Therefore, based on this, the trust authority can track the user who uses the currency through a database stored in the trust authority through the unique number of the forged currency.

In practice, the user tracking method of money embedded with the RFID tag can be utilized as follows.

After the store's leader communicates with the currency's tags, the store's own database stores the unique number of the currency and the user's identification number. The store's database sends information to the central bank on a daily basis, including a unique number and user information.

It then stores the unique number of the currency and the user's identification information in the store's own database. The store's database transmits the unique number and user information to the central bank on a daily basis.

If a forgery occurs in the currency, the store sends information about the forgery generated currency to the trusting authority, which stores and manages the information in a database.

The trust authority can then track the user using that number through the unique number of the forged currency.

The present invention can be embodied as code that can be read by a computer (including all devices having an information processing function) in a computer-readable recording medium.

The computer-readable recording medium includes all kinds of recording devices in which data is stored which can be read by a computer system. Examples of computer-readable recording devices include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, etc. Computer-readable recording media are also distributed and distributed over networked computer devices. Computer readable code may be stored and executed in such a manner.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical details of the appended claims.

As described above, according to the present invention, whether the forgery of money can be identified through the reader using the RFID reader instead of the naked eye through the RFID tag embedded in the money, so that the general public can easily determine whether the forgery of the money. In addition, it is possible to protect the privacy of money holders, which can be generated by using the RFID tag, and to reduce the amount of computation in the process of encrypting and decrypting because the encryption is performed using an exclusive logical sum.

Claims (14)

A first cipher text storage unit for storing a first cipher text randomly generated according to a tag key previously stored in a tag; A counter unit for updating a counter value each time a query of a reader occurs; A second ciphertext generation unit configured to generate a second ciphertext using the first ciphertext updated at the counter and randomly selected for each currency and a stored random number as an input value of a hash function; A transmission unit which transmits the generated second cipher text and the counter value whenever an inquiry of the reader occurs; And Money embedded with an RFID tag including a memory for storing information about the money. The method of claim 1, The memory, An optical memory area for storing a signature and a verification value generated based on the unique number of the currency, the unique number of the currency and the currency unit of the currency; A transmission memory area for storing a second ciphertext generated by the second ciphertext generator and a counter value of the counter unit, and transmitting the second ciphertext and the counter value to the transmission unit when an inquiry of the reader occurs; And Money with an RFID tag, characterized in that the internal memory area for storing the random value and the hash function. The method of claim 2, And the verification value is generated by a tag key stored in the tag and a public key publicly disclosed in advance. The method of claim 1, The second cipher text, And a RFID tag embedded money generated by an exclusive logical OR of the result of the first cipher text and the hash function. Generating a signature of each currency by a signature algorithm based on the monetary unit of each currency to which a unique number is assigned; Generating a first cipher text using the unique number of the currency, the currency unit, the generated signature, a tag key stored in a tag of the currency and a public key previously disclosed; Generating a randomized second cryptogram using the first cryptogram in the tag of the currency; And When the user withdraws the currency stored the generated second cipher text, the encryption method of the RFID tag embedded currency comprising storing the information of the withdrawn currency and the information of the withdrawn user in a database of a central server . The method of claim 5, wherein Generating the second cipher text, Whenever a query of a reader occurs, the second ciphertext is generated based on a value generated by using an updated counter value and a randomly selected random number value for each currency as an input value of a hash function. Encryption method. The method of claim 6, And the input value of the hash function is a value generated by an exclusive logical sum of the counter value and the random number value. The method of claim 6, And the second cipher text is a value generated by an exclusive logical sum of the first cipher text and a result value of the hash function. Generating a first cipher text using a unique number of a currency, a currency unit, a signature generated by a signature algorithm when issuing the currency, a tag key randomly generated and stored in a tag of the currency, and a public key; Generating a second randomized cipher text using the first cipher text and storing the randomized second cipher text in a tag of the currency; When the RFID reader inquires the tag, verification generated by the unique number of the currency stored in the optical memory area of the tag, the signature, a randomly preselected random number for each currency, the tag key and the public key of the currency Transmitting a counter value which updates a value by itself according to a value, the second cipher text, and a query of a reader, to the reader; Generating a first ciphertext using the hash function in which the transmitted second ciphertext is an exclusive logical sum of the counter value and the random number as an input value; And A method of verifying forgery and tampering with embedded RFID tag, comprising: checking whether the money is forged or forged using the generated first cipher text. The method of claim 9, Determining whether the currency is forged, And verifying whether the money is forged or altered by the verification value of the money transmitted from the optical memory region of the tag. Generating a first cryptogram using a unique number of a currency, a currency unit, a signature generated by a signature algorithm when issuing the currency, a public key and a tag key of the currency; Generating a second randomized cipher text using the first cipher text and storing the randomized second cipher text in a tag of the currency; When the RFID reader inquires a tag, the tag itself may be generated according to a unique number of the optical memory area of the tag, the signature, a randomly selected random value for each currency, a verification value stored in the currency, the second cipher text and a query of the reader. Transmitting the updated counter value to the reader; A verification value stored in the optical memory area from the first cipher text by generating a first cipher text by using a hash function having the transmitted second cipher text as an input value using an exclusive logical sum of the counter value and the random number; Checking whether the currency is forged using; If the currency is forged, transmitting the second cipher text, the counter value, and the random number value to a trust authority in the reader, and calculating the first cipher text using the hash function in the trust authority; And Calculating a unique number and signature of the currency from the first cipher text using a secret key of the trust authority, and tracking a user of the currency according to the unique number; Way. The method of claim 11, And the signature is a value calculated by a signature algorithm using a unique number and a currency unit assigned to each currency. The method of claim 11, The verification value is, And a value generated by the public key and a tag key stored in the tag. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 5 to 13.

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