KR20230053990A - Survey methods and system on blockchain that perform personal information collection of respondents using survey token - Google Patents

Abstract

A survey method and system using a survey token and blockchain is provided. The survey method using a survey token and blockchain comprises the steps of: creating a survey and recording the survey on a blockchain; receiving data for identification of a respondent from the respondent participating in the survey, generating a survey token signed with the private key of an issuer, and providing the survey token to the respondent; providing a survey token signed with the private key of the respondent as a transaction to the blockchain along with the survey results; and verifying a valid transaction among the transactions, recording the transaction in the blockchain, and tallying the survey results. Accordingly, the integrity of answers can be guaranteed.

Description

A survey method capable of collecting personal information of a respondent on a blockchain using a survey token and a system for performing it

The present invention relates to a survey method capable of collecting metadata of a respondent on a blockchain using a survey token and a system for performing the same, and more specifically, to a block using a survey token containing personal information and metadata. It relates to a method and system capable of conducting a survey secured by recording it as an on-chain transaction.

Blockchain originated from Satoshi Nakamoto's Bitcoin: A Peer-to-Peer Electronic Cash System in 2008, where blocks are connected to each other. Blockchain is a generic term for a distributed database that shares data bound by hash links on a distributed network composed of multiple network nodes.

Data recorded in the blockchain is virtually impossible to forge and alter, and by using the characteristics that anyone can check the data with guaranteed integrity by connecting to the blockchain, the introduction is progressing in the field of data operation that requires reliability and transparency. It is becoming.

The reliability and transparency of these blockchains can also be used in surveys to collect opinions or responses from multiple respondents. In particular, a method of conducting a survey using a survey token by recording respondents' answers in a blockchain and transparently disclosing them, while applying encryption so that only the issuer of the survey can access personal information that requires anonymity. development is required.

The technical problem to be solved by the present invention is to provide a method and system capable of conducting a survey with security secured by recording it as a transaction on a blockchain using a survey token containing personal information and metadata.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

A method of conducting a survey on a blockchain using a survey token to solve the above-described technical problem includes generating and recording a survey in a blockchain, identifying a respondent from respondents participating in the survey. Receiving the data, generating a survey token signed with the issuer's private key and providing it to the respondent, providing the survey token signed with the respondent's private key to the blockchain along with the survey results as a transaction; and verifying that the transactions are valid, recording them in the blockchain, and aggregating survey results.

In some embodiments of the present invention, the survey includes a public survey, and generating the survey token and providing the survey token to the respondent results in signing a hash of the respondent's public key with the issuer's private key. It may include generating a survey token using

In some embodiments of the present invention, providing the survey token signed with the respondent's private key to the blockchain along with the survey results as a transaction includes signing the transaction data including the survey token with the respondent's private key. and providing the generated transaction to the blockchain.

In some embodiments of the present invention, the survey includes an anonymous survey, data for identification of the respondent is provided from a respondent participating in the survey, and a survey token signed with an issuer's private key is generated to In the step of providing the responder, a hash of the responder's public key blinded with a nonce is provided together with data for identification of the responder, and the blinded hash is generated by signing with the issuer's private key. and providing a survey token to the respondent.

In some embodiments of the present invention, the method may further include, after providing the survey token to the respondent, unblinding the survey token to the nonce by the respondent.

In some embodiments of the invention, the data for identification of the respondent includes metadata of the respondent, and the survey token includes information about the metadata. can be

In some embodiments of the present invention, the survey may include an open survey, and the puzzled survey token may include a result of encrypting an internal database address in which the metadata is stored.

In some embodiments of the invention, the survey comprises an anonymous survey;

The step of receiving data for identification of the respondent from the respondent participating in the survey, generating a survey token signed with the issuer's private key, and providing the survey token to the respondent is blinded with a nonce from the respondent. Receiving a package including a hash of the public key of the respondent and metadata of the respondent, and providing the respondent with a survey token generated by signing the blinded hash and metadata with the private key of the issuer. .

In some embodiments of the present invention, the step of verifying that the transaction is valid, recording it in the blockchain, and aggregating the survey results includes providing a survey token signed with the respondent's private key included in the transaction to the issuer. This may include verifying with a public key.

In some embodiments of the present invention, providing a result of providing the signed survey token as a transaction to a blockchain to a vendor as a result of the survey; and verifying the survey participation evidence and providing a reward to a respondent whose verification is completed.

Details of other embodiments are included in the detailed description and drawings.

According to the method and system for conducting a survey on a blockchain using a survey token according to an embodiment of the present invention, personal information or metadata included in the survey token is not exposed to the outside world except for the issuer. Since it is possible to submit and aggregate answers to surveys, the anonymity of surveys can be guaranteed, and since survey responses are recorded as transactions in the blockchain, the integrity of answers can be guaranteed.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a block diagram of a system for conducting a survey on a blockchain using a survey token, in accordance with some embodiments of the present invention.
2 is a data flow diagram illustrating a survey method performed on a blockchain using a survey token according to some embodiments of the present invention.
3 is a diagram for explaining initialization of a survey according to some embodiments of the present invention.
4A is a diagram for explaining generation of a survey token for an open survey according to some embodiments of the present invention.
4B is a diagram for explaining generation of a survey token for an anonymous survey according to some embodiments of the present invention.
5A is a diagram for explaining generation of a puzzled survey token for an open survey according to some embodiments of the present invention.
5B is a diagram for explaining generation of a puzzled survey token for an anonymous survey according to some embodiments of the present invention.
6A is a diagram for explaining immediate response submission of a respondent included in a survey method according to some embodiments of the present invention.
6B is a diagram for explaining a respondent's delayed response submission included in a survey method according to some embodiments of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

A component is said to be "connected to" or "coupled to" another component when it is directly connected or coupled to the other component or through another component in between. include all cases. On the other hand, when one component is referred to as “directly connected to” or “directly coupled to” another component, it indicates that another component is not intervened. “And/or” includes each and every combination of one or more of the recited items.

Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" means that a stated component, step, operation, and/or element is present in the presence of one or more other components, steps, operations, and/or elements. or do not rule out additions.

Although first, second, etc. are used to describe various constituent elements, these constituent elements are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may also be the second component within the technical spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

1 is a block diagram of a system 1 for conducting a survey on a blockchain using a survey token, in accordance with some embodiments of the present invention.

Referring to FIG. 1, a system 1 for conducting a survey on a blockchain using a survey token according to some embodiments of the present invention includes an issuer 100, a respondent 200, a vendor 300, and a blockchain (500). Components such as the issuer 100, the responder 200, and the vendor 300 described below are blockchains such as smartphones, personal computers (PCs), server computers, tablet PCs, and hardware wallets. On 500, a computing device capable of generating a survey or submitting answers may be included.

The issuer 100 may manage the entire process of the survey 110 performed in the present invention. The issuer 100 may generate the survey 110 , authenticate respondents 200 who wish to participate in the survey, and aggregate the results of the survey 110 .

The survey 110 created by the publisher 100 may be defined to have various characteristics according to its purpose. For example, the survey 110 may be an open survey or an anonymous survey, with immediate response submissions allowing immediate counting of votes, or encrypted responses allowing delayed counting. may be a submission.

In addition, the survey 110 is a vote in which a survey token including only personal information for identification of the respondent 200 is used, or a puzzled survey token including metadata of the respondent 200. This may be the vote used.

A puzzled survey token refers to a survey token that can be generated by combining only information required by the issuer 100 conducting the survey 110 like a puzzle. The respondent 200 may be provided with a puzzled survey token by authenticating qualifications based on information previously input about the issuer 100 . When the issuer 100 generates a puzzled survey token, it can create a unique token for each respondent 200 who receives a puzzled survey token, since it can be created by combining only the necessary information among the personal information for identification of the respondent. will be provided. As described below, the personal information combined for the generation of the puzzled survey token may be encrypted.

Not only can the respondent 200 use the puzzled survey token provided to the survey described below, but also the respondent 200's unique qualification or identity by providing the puzzled survey token to a third party. can be used as a kind of ID that can be verified.

At this time, the puzzled survey token issued by the issuer 100 does not include personal information related to the respondent 200 .

In addition, the respondent 200 may participate in the survey by combining the puzzled survey token with the survey results and personal information about the respondent 200 expressed as metadata. The issuer 100 may obtain more detailed survey results by analyzing the metadata along with the survey results included in the puzzled survey token.

The issuer 100 may generate an issuer-specific private key (Priv _I ), a unique key (Pub _I ), and the like. As described later, when the survey token 120 used in the survey 110 is a puzzled survey token, the issuer 100 provides a symmetric key (Key _I ) for encrypting and decrypting the puzzled survey token. and a pair of keys (Enc _M , Dec _M ) necessary for encryption and decryption of metadata included therein.

The issuer 100 verifies the qualification of the respondent 200 in response to a survey participation request including personal identification data or metadata from the respondent 200, and the respondent 200 who has successfully passed the verification A survey token 120 may be provided for.

In this process, one or more signatures may be generated by using a key to generate the survey token 120 or the like.

In addition, the issuer 100 announces the start and end of the survey 110, or collects valid transactions for the survey results recorded in the form of transactions on the blockchain 500 and posts them to the block chain. Aggregation of surveys can be performed.

The responder 200 may provide the issuer 100 with a survey participation request including personal identification data or metadata, and may perform the survey using the survey token 120 provided in response to the request. The survey may be performed by recording a transaction in the blockchain to send the survey token 120 to an address on the blockchain 500.

In the embodiment of FIG. 1 , respondent 200 is illustratively shown using survey application 400 to conduct survey 110 . The survey application 400 may include an application program executed on a computing device such as a smart phone, a tablet PC, a desktop computer, or a notebook computer to perform the survey 110 and submit answers, but the present invention is limited thereto. it is not going to be

Although FIG. 1 shows a system 1 for conducting a survey on a blockchain using a survey token as including one respondent 200, the present invention is not limited thereto. It goes without saying that a survey on a plurality of respondents 200 can be performed to meet the purpose of the survey performed by the present system 1 .

In addition, the respondent 200 may present evidence of participation in the survey to the vendor 300, receive a reward provided when the verification of the evidence is completed, and store it. The vendor 300 verifies the claim for the reward provided by the responder 200 and, if the claim is valid, may provide the reward to the wallet address of the responder 200 or the address specified in the claim.

The blockchain 500 may include a network in which nodes composed of a plurality of computing devices are connected to each other. A plurality of nodes constituting the blockchain 500 can mutually verify transactions or smart contracts executed to proceed and record the entire process of the survey. In the blockchain 500, the survey 110 generated by the issuer 100, the survey responses generated by the respondent 200, and the result of aggregating the answers may be recorded.

2 is a data flow diagram illustrating a survey method performed on a blockchain using a survey token according to some embodiments of the present invention.

Referring to FIG. 2 , a survey method performed on a blockchain using a survey token according to some embodiments of the present invention includes generating and announcing a survey from an issuer 100 (S110), a respondent 200 ) performs registration for a survey with the issuer 100 using personal identification data or metadata (S120), the issuer 100 verifies the qualifications of the respondent 200, and as a result of the verification, the respondent 200 ) has valid qualifications, generating a survey token and providing it to the respondent 200 (S130), and submitting the survey answer to the blockchain 500 using the survey token from the respondent 200 ( S140), the issuer 100 aggregating the survey answers recorded on the blockchain 500 (S150), the issuer 100 storing the survey results in the blockchain 500 based on the aggregated survey answers (S150) Recording (S160), the respondent 200 providing the survey participation evidence to the vendor 300 (S170), the vendor 300 verifies the survey participation evidence and rewards the respondent's wallet on the blockchain The step of providing (S180) and the like may be included. Each step of a survey method according to an embodiment of the present invention will be described with reference to the following drawings.

3 is a diagram for explaining initialization of a survey according to some embodiments of the present invention.

Referring to FIG. 3 , the issuer 100 may initialize a survey by generating and announcing a survey 110 . Issuer 100 may generate one or more public and private key pairs (Pub _I , Priv _I ) for use in signing survey tokens 120 .

In addition, as described later, when the survey token 120 is a puzzled survey token including metadata of the respondent 200, a key (Key _I ) for encrypting and decrypting the puzzled survey token is generated. can do. The key (Key _I ) may be used in a symmetric key encryption algorithm, and such an algorithm may include an Advanced Encryption Standard (AES) algorithm, but the present invention is not limited thereto.

The issuer 100 may declare an identifier (SurveyID) for identifying the survey to create the survey 110 . The identifier (SurveyID) may include, for example, a hash of a string included in the string identifier of the survey, and an algorithm for calculating the hash may include, for example, SHA-2, SHA-3, etc., but the present invention This is not limited to this.

The survey 110 created by the publisher 100 may include, for example, JSON, YAML, TOML, XML, or structured documents in a format that can be processed by the survey app 400 . Such documents may contain at least one or more questions. In addition, the survey 110 may include contact point information that a respondent who wants to participate accesses to request a survey token along with personal data.

In addition, the survey 110 may include a structured query document (RespondentDoc) capable of recording personal information (hereinafter referred to as metadata) about the respondent 200 . When the survey 110 including the document (RespondentDoc) is provided to the respondent 200 from the issuer 100, the respondent 200 may create metadata by filling out the form of the document (RespondentDoc). The metadata may include, for example, various questions related to personal information such as age, place of birth, and gender of the respondent 200 .

In this case, the issuer 100 may assign certain conditions to qualifications for participating in the survey 110 . For example, restrictions on a specific gender, age group, region of residence, etc. are added, and then, when a survey token including metadata is provided from the respondent 200, response results are filtered according to the predetermined conditions, and survey aggregation is performed. available.

The issuer 100 may define a survey method of the survey 110 together with the creation of the survey 110 . The survey 110 may include, for example, an open survey in which the identity of the respondent 200 is disclosed and responses can be traced, or an anonymous survey in which no trace of the respondent is possible.

In addition, the issuer 100 may define a method of aggregating the survey 110 together with the creation of the survey 110 . The aggregation of answers to the survey 110 may include immediate aggregation immediately after submission by the respondents 200 and delayed aggregation that can be checked only after all respondents 200 complete their submission of answers.

If the answers of the survey 110 are counted by delayed counting, the respondent 200 may generate a key pair (Enc _I , Dec _I ) for encrypting the answers of the respondent 200 .

The issuer 100 may publish the survey 110 by completing the creation of the survey 110 and recording the generated survey 110 in the blockchain 500 . The survey 110 recorded on the blockchain 500 may be accessible by any respondent by being public.

In some embodiments of the present invention, before the survey 110 is created by the issuer 100, an unspecified number of participants who are targets of the survey 110, that is, a respondent who can be provided with a survey token ( 200) Predetermined information may be provided from the candidate. Predetermined information on the provided respondent 200 candidates may be used to verify respondent qualifications when the respondent 200 provides a survey participation request to the issuer 100 .

4A is a diagram for explaining generation of a survey token for an open survey according to some embodiments of the present invention.

Referring to FIG. 4A , the respondent 200 recognizes the survey 110 generated by the issuer 100, provides a survey participation request to the issuer 100 for an open survey, and verifies the respondent's qualifications. Upon completion, the survey token is shown being provided to the respondent 200 .

Respondent 200 may extract contact information capable of accessing issuer 100 from survey 110 recorded in blockchain 500 . The respondent 200 may request the survey token 120 from the issuer 100 by transmitting personal data and a hash through the corresponding contact. Meanwhile, the respondent 200 may generate a wallet address on the blockchain 500 used as the source address of the transaction before requesting the survey token 120 . Afterwards, the vendor 300 may provide a reward for participating in the survey to the wallet address of the respondent 200 .

Respondent 200 may generate a public key (Pub _V ) for verifying survey 110 transactions and a private key (Priv _V ) used to sign survey 110 transactions. The public key (Pub _V ) and the private key (Priv _V ) of the responder 200 may match each other.

The responder 200 may provide the responder's public key (Pub _V ) to the issuer 100 together with personal identification data for identifying the responder's identity. In addition, the respondent 200 may sign the survey participation request including the personal identification data with the respondent's private key (Priv _V ) and provide it to the issuer 100 .

Personal identification data of the respondent 200 may include, for example, the respondent's 200 wallet address, affiliation, title, security level, and the like.

Upon receiving the survey participation request from the respondent 200, the issuer 100 may check the personal identification data of the respondent 200 included in the request and evaluate eligibility to participate in the survey. This evaluation may be based on, for example, whether the personal identification data of the respondent 200 matches the respondent list previously stored by the issuer 100, but the present invention is not limited thereto.

When the evaluation of the respondent 200 is completed, the issuer 100 may generate a survey token. The survey token (SurveyToken _I ) may contain the result of signing the hash of the respondent's public key (Pub _V ) with the issuer's private key (Priv _I ) (SurveyToken _I = Sign(hash(Pub _V ), Priv _I ). Here, Sign(bytes, privKey), which performs the operation of signing the byte string bytes with the private key privKey, is, for example, DSA (Digital Signature Algorithm) signature, ECDSA (Elliptic Curve Digital Signature Algorithm) signature, or Ed25519 or other known A digital signature algorithm can be used.

In addition, the issuer 100 may generate a survey token by combining the personal identification data of the respondent 200 previously provided. The token generated in this way may function as a kind of NFT by becoming a unique token of the responder 200 .

The generated survey token 120 may be provided to the respondent 200 through a secure channel. The responder 200 may keep the token 120 provided for a later step as it is without separate processing.

4B is a diagram for explaining generation of a survey token for an anonymous survey according to some embodiments of the present invention.

The anonymous survey illustrated by FIG. 4B includes a survey process in which the identity of the respondent 200 is not disclosed even by the issuer 100 . That is, a series of processes in which the issuer 100 signs with its own private key and provides it to the responder 200 without knowing information about the responder's private key provided by the responder 200 will be described below.

Referring to FIG. 4B, the respondent 200 recognizes the survey 110 generated by the issuer 100, provides a request to participate in the survey to the issuer 100 for an anonymous survey, and verifies the qualifications of the respondent. Upon completion, the survey token is shown being provided to the respondent 200 . As will be described later, separate steps for preventing identification of respondents may be additionally performed when an anonymous survey is performed, unlike an open survey.

Extracting the contact information of the issuer 100 by the respondent 200 and generating the private/public keys (Priv _V and Pub _V ) may be the same as in the case of the public survey described above.

Meanwhile, the responder 200 may generate a blind hash of the public key of the responder and provide it to the issuer 100 together with personal identification data of the responder 200 .

Specifically, the responder 200 may calculate the hash (hpk) of the responder's public key (Pub _V ) (hpk = hash(Pub _V )). In addition, the responder 200 may calculate a blinded result (bpk) of the hash (hpk) of the public key using the issuer's public key (Pub _I ) and a randomly generated nonce (bpk = Blind (hpk, Pub _I , nonce)).

Here, "blind" may refer to a protocol capable of safely signing a byte string without disclosing the contents of the byte string, such as Blind RSA signature. In such a blind signature, the sender's message is blinded until the recipient signs it, and the signing party does not know the contents of the message. The sender can obtain a properly signed message by unblinding the signed message.

Responder 200 may provide a blind hash (bpk) of the responder's public key along with the responder's personal identification data to issuer 100 over a secure communication channel. The issuer 100 may generate a survey token (SurveyToken _I ) when the evaluation of the respondent 200 is completed. The survey token (SurveyToken _I ) may include a result of RSA signing the provided blind hash (bpk) with the issuer's private key (Priv _I ) (SurveyToken _I = SignRSA(bpk, Priv _I )). Here, SignRSA(bytes, privKey), which performs the operation of RSA signing the byte string bytes with the private key privKey, calculates the large integer m obtained from the array of byte strings as the exponent e and modulo N (num(bytes)^e mod N) can mean that.

The responder 200 may unblind the survey token (SurveyToken _I ) provided from the issuer. That is, an unblinded survey token (SurveyTokne _V ) is generated (SurveyToken _V = Unblind (SurveyToken _I , nonce) using the nonce used when generating the blind hash (bpk) of the public key earlier.

The key feature of the series of processes through the above blind and unblind operations is that the unblinded survey token (SurveyToken _V ) obtained by the respondent 200 is SignRSA (hash(Pub _V ), Priv _I ), that is, the respondent's public key. It is identical to the publisher's signature for (Pub _V ). Thanks to the blind signing process, the issuer 100 signs without knowing the value of the responder's public key (Pub _V ). If the respondent 200 uses its key (Priv _V ) to sign the survey transaction, no one, including the issuer 100, will be able to trace the actual respondent.

5A is a diagram for explaining generation of a puzzled survey token for an open survey according to some embodiments of the present invention. The puzzled survey token described in FIGS. 5A and 5B may refer to a survey token including some additional information about the respondent 200, such as age, region of origin, gender, and the like, that is, metadata. By including such metadata in the puzzled survey token, verifiable information about the respondent 200 can be provided to the issuer 100 without infringing on the personal information of the respondent 200 . That is, the survey can be conducted based on the minimum personal information voluntarily provided by the respondent 200, and personal information leakage is prevented by using metadata that can be identified and decrypted only by the issuer 100 as will be described later. And it is possible to secure the data owner of the subject of personal information.

Metadata may be composed of documents in a structured format such as, for example, JSON, YAML, TOML, XML, and the like.

The metadata may be stored in an internal database of the issuer 100, and the internal database may include an EntryID to uniquely identify the stored metadata. The puzzled survey token may also contain an EntryID, or oeid, encrypted with an opaque reference to its metadata.

Referring to FIG. 5A, a respondent 200 recognizes a survey 110 generated by an issuer 100, provides a survey participation request to the issuer 100 for an open survey, and verifies the respondent's qualifications. When this is completed, the puzzled survey token is provided to the respondent 200 .

If survey 110 is an open survey, respondent 200 may provide personal information to publisher 100 that may be included in metadata along with personal data for identification. The issuer 100 may complete the metadata of the respondent 200 by referring to the provided personal information and store it in an internal database.

While the respondent 200 extracts the contact information of the issuer 100 included in the survey 110, a structured query document (RespondentDoc) capable of recording personal information about the respondent 200 may be completed.

The respondent 200 signs the request to participate in the survey with the respondent's private key (Priv _V ) along with a document (RespondentDoc) including his/her public key (PubV), personal identification data, and metadata, and the issuer (100) can be provided to

The issuer 100 may check the personal data of the respondent 200 among the provided data and evaluate eligibility to participate in the survey. In addition, the metadata of the responder 200 may be stored in the internal database of the issuer 100 so that it can be identified with a unique EntryID.

The issuer 100 may encrypt the EntryID to generate an opaque metadata ID (oeid) (oeid = Enc(EntryID, Key _I ). Here, asymmetric encryption of a bytes string is calculated using the specified key. Enc(bytes, key) may include using a known encryption algorithm.

In addition, the issuer 100 signs the hash of the respondent's public key (Pub _V ) with the issuer's private key (Priv _I ) (sk = Sign(hash(PubV), Priv _I ) and puzzles for the progress of the public survey. It is possible to calculate the hash (hd) of the data structure of the de survey key (sk) (hd = hash (oeid || sk). Finally, the issuer 100 includes a pair of data in which the digital signature of the issuer is written. A puzzled survey token (PuzzSurveyToken _I ) can be created (PuzzSurveyToken _I = [oeid, sk, Sign(hd, Priv _I )).

The issuer 100 may keep the generated puzzled survey token (PuzzSurveyToken _I ) as the issuer's puzzled survey token (PuzzSurveyToken _V = PuzzSurveyToken _I ).

5B is a diagram for explaining generation of a puzzled survey token for an anonymous survey according to some embodiments of the present invention.

Using the hash blinded by the respondent 200 to perform an anonymous survey using a puzzled survey token including metadata is similar to the description of FIG. 4B above.

Specifically, referring to FIG. 5B , the respondent 200 extracts the contact information of the issuer 100 included in the survey 110 and generates metadata (md) using personal information about the respondent 200. can be created directly. That is, unlike the previous public survey in which the issuer 100 constructed metadata from the respondent 200's personal information, in the anonymous survey using the puzzled survey token, the respondent 200 uses his or her metadata (md). can be created directly.

Subsequently, the responder 200 may construct a merkel tree (mt) using the metadata (md) and the responder's public key (Pub _V ) (mt = hash(hash(Pub _V ) || hash (md))). That is, the responder 200 configures the merkle tree mt by forming a hash of a value obtained by combining the hash of the responder's public key (Pub _V ) and the hash of the metadata (md).

The responder 200 generates a value (bmt) obtained by blinding the public key (Pub _V ) of the responder and the Merkle tree (mt) of the metadata (md). Specifically, the responder generates two random nonces (nonce1, nonce2), and uses the issuer's public key (Pub _I ) and the nonce (nonce1) to blind the hash (hpk) of the responder's public key (bpk). ) can be calculated (bpk = Blind(hpk, Pub _I , nonce1).

Subsequently, the responder 200 may calculate a result (bmt) of blinding the Merkle tree root (mt) using the issuer's public key (Pub _I ) and the nonce (nonce2) (bmt = Blind(mt, Pub _I , nonce2).

Responder 200 provides a package containing the blinded hash of the public key (bpk), the blinded merkle tree root (bmt), the metadata (md) and the responder's private data to the issuer 100 via a secure communication channel. can do.

The issuer 100 may evaluate the qualification of the responder 200 by verifying the personal identification data of the respondent 200 and comparing it with the provided meta data md. When the qualification of the responder 200 is verified, the issuer 100 may issue a signed puzzled survey token (PuzzSurveyToken _I ) from the issuer and provide it to the responder 200 . The signed puzzled survey token (PuzzSurveyToken _I ) uses the issuer's private key (Priv _I ) to generate an RSA signed hash (sbpk = SignRSA (bpk, Priv _I )), a Merkle tree (sbmt = SignRSA (bmt, Priv I )) _I )) and the signed metadata (smd = Sign(hash(md), Priv _I )) and the signature of the sum of the above three values (Sign(hash(sbpk || sbmt || smd), Priv _I )) can include

The responder 200 may generate a puzzled survey token (PuzzSurveyToken _V ) using a puzzled survey token (PuzzSurveyToken _I ) signed by the issuer.

Specifically, the puzzled survey token (PuzzSurveyToken _V ) is the result of unblinding the hash (sbpk) of the RSA signed public key and the blind Merkle tree root (sbmt) using the nonces (nonce1, nonce2) used during blinding. The issuer _'s encryption key (Enc It may include the result of encryption with _M ) (ekey = Enc(Key _V , Enc _M )) and the result of symmetric key encryption using AES key (Key _V ) (emd = EncSym(md, Key _V )). .

What is noteworthy here is that the values of spk, smt, smd, ekey, and emd of the puzzled survey token (PuzzSurveyToken _V ) generated by the respondent 200 are SignRSA (hpk, Priv _I ), SignRSA (mt, Priv _I ) and Sign(hash(md), PrivI), corresponding to encrypted metadata that can only be decrypted by the issuer 100. That is, the signature of the public key signature of the respondent by the issuer and the Merkle tree root of the public key combined with the metadata is included in the puzzled survey token (PuzzSurveyToken _V ). Blind signing allows issuer 100 to sign hashes of the responder's and issuer's public keys without knowing the data itself. Accordingly, if a respondent 200 signs a survey transaction with the respondent's private key (Priv _V ), no one can trace the actual respondent.

The rationale for metadata encryption is to keep the metadata private from outside observers so that only the issuer 100 can access the metadata of the responder 200 . To this end, the issuer 100 generates a decryption result (key') of the ekey using the private key (Priv _I ) of the issuer (key' = Dec(ekey, Priv _I )).

Subsequently, the issuer 100 generates a result (md') of decrypting the metadata using the decrypted key (key') (md' = DecSym(emd, key')).

The issuer 100 may verify the decrypted metadata md'. Specifically, the issuer 100 uses the issuer's public key (Pub _I ) to verify the issuer's puzzled survey token (PuzzSurveyTokenI) smd (metadata (md) signed using the private key (Priv _I )). hash) matches the hash of the decrypted metadata (md') (Verify(hash(md'), smd, Pub _I ). If the verification result matches, the issuer 100 issues the decrypted meta data (md'). Data (md') can be stored in an internal database.

In summary, since there is no link from the public key (Pub _V ) of the respondent 200 to the personal information or metadata of the actual respondent 200, the metadata (md') is anonymous, and the respondent (200 ) may not reveal any personally identifiable information.

The respondent 200 may combine survey responses to form a structured document, sign the resulting data structure to which the survey token (SurveyToken _V or PuzzSurveyToken _V ) is attached, and record it as a transaction in the blockchain 500. there is. At this time, the submission of answers can be classified into two types: submission of immediate answers that can be counted immediately after submission, and submission of encrypted answers that can be counted with delay.

6A is a diagram for explaining immediate response submission of a respondent included in a survey method according to some embodiments of the present invention.

Referring to FIG. 6A, the respondent 200 generates transaction data (VoteTx_Data) including a survey token (SurveyToken _V ) and the like, and a transaction (VoteTx) including a result of signing the data with the respondent's private key (Priv _V ). can create The responder 200 may provide the transaction (VoteTx) to the blockchain 500.

Each node included in the blockchain 500 may verify the validity of the transaction (VoteTx) submitted by the responder 200 .

First, it may be checked whether a survey having an identifier (SurveyID) is currently in progress. If the transaction (VoteTx) is submitted before the progress period or submitted after the progress period ends, the transaction (VoteTx) may be rejected.

In addition, whether the answer included in the transaction (VoteTx) corresponds to the document (SurveyDoc) included in the survey 110 announced by the respondent and the public key (pk = Pub _V ) included in the transaction data (VoteTx_Data) It can be confirmed whether the signature of the transaction (VoteTx) can be verified by (Verify(data, sign, pk)).

Alternatively, a process in which the public key (Pub _V ) of the responder 200 is approved by the issuer 100 may proceed. Specifically, in the case of a public survey, since the survey token (SurveyToken _V ) is the signature of the hash of the public key (Pub _V ) of the respondent, it can be verified by the public key (Pub _I ) announced by the issuer. For an anonymous survey, the survey token (SurveyToken _V ) may contain an RSA signature (SignRSA(hash(Pub _V ), Priv _I ) of the respondent's public key (Pub _V ) by the issuer's key (Priv _I ); , which can be verified by the issuer's public key (Pub _I ).

Finally, the transaction (VoteTx) must be the first transaction (VoteTx) signed by the responder's private key (Priv _V ). If there is another transaction signed with this key (Priv _V ) for a given survey identifier (SurveyID), this corresponds to double answering and can be rejected.

When the transaction (VoteTx) completes validation by the above-described procedure, the block chain 500 may record the corresponding transaction (VoteTx).

6B is a diagram for explaining submission of an encrypted answer by a respondent included in a survey method according to some embodiments of the present invention.

Referring to FIG. 6B, the respondent 200 encrypts encrypted transaction data (EncryptedVoteTx_Data) including a survey token (SurveyToken _V ) and the like, and a result of signing the data with the respondent's private key (Priv _V ). You can create an encrypted transaction (EncryptedVoteTx).

Here, the encrypted transaction data (EncryptedVoteTx_Data) may include an encrypted answer of the responder 200. The respondent's answers may be included in the transaction data (EncryptedVoteTx_Data) encrypted by one of the key pairs (Enc _I , Dec _I ) generated by the issuer 100 in the survey generation step (Enc _I ) to encrypt the answers. there is. When an encrypted answer is submitted, a delayed tally begins after the survey has ended. As the encrypted answer is submitted, the subjects involved in voting cannot know the counting status during voting.

The responder 200 may provide the encrypted transaction (EncryptedVoteTx) to the blockchain 500.

Each node included in the blockchain 500 may verify the validity of the encrypted transaction (EncryptedVoteTx) submitted by the responder 200. That is, the survey progress period, which is the validation step of the transaction (VoteTx) described above with reference to FIG. 6A, the format of the answer, signature verification of the delayed transaction, approval by the issuer 100 of the respondent's public key (Pub _V ), It may be verified whether the encrypted transaction (EncryptedVoteTx) is the first transaction signed with the responder's private key (Priv _V ).

The issuer 100 may perform survey aggregation by aggregating transactions of answers submitted by the respondents 200 and recorded in the blockchain 500 (S150).

In the case of immediate answer submission described with reference to FIG. 6A , when the survey period ends, the issuer 100 may count valid transactions and collect and process answer documents included in the transactions.

In the case of the delayed answer submission described with reference to FIG. 6B, since the answer is encrypted by the key (Enc _I ), a procedure for decrypting it is required. Issuer 100 may write another key (Dec _I ) to blockchain 500 at the end of the survey period so that other participants with access to blockchain 500 can decrypt the encrypted answer. . Other participants with access to the blockchain 500 can repeat all encrypted transactions (EncryptedVoteTx) in the blockchain and decrypt the encrypted answer document included in each transaction using the key (Dec _I ). The issuer 100 may collect decrypted answer documents and generate an aggregate result. The aggregation result may be signed by the issuer 100 and recorded in the blockchain 500 (S160).

In addition, the issuer 100 may aggregate the metadata included in the survey token by using the aggregate result collected through the decrypted answer document as a ratio. As described above, when creating the survey 110, the issuer 100 may assign conditions regarding a specific gender, age group, region of residence, etc., and may filter the survey results based on the conditions when aggregating the survey results. there is. In addition, the issuer 100 can separately aggregate the metadata of the respondents 200 who participated in the survey and use it as a kind of big data, and additionally utilize the information previously entered by the participant when analyzing the survey results, thereby providing more accurate respondent data. Analysis and survey result analysis can be performed.

The respondent 200 may present evidence of participation in the survey to the vendor 300 (S170). When the public survey was conducted, the respondent 200 sent an identifier (txID) generated by recording the survey transaction (VoteTx or DelayedVoteTx) on the blockchain 500 and a message signed with his/her private key (PrivV) to the vendor ( 300) can be provided. The vendor 300 may verify the signed message using the public key (pk = Pub _V ) of the respondent 200 included in the survey transaction (VoteTx or DelayedVoteTx). When verification is complete, the vendor 300 may transmit a reward to a wallet on the blockchain 500 connected to the user's public key (Pub _V ).

In the case of an anonymous survey, if the respondent 200 simply presents his/her public key (Pub _V ) and the survey transaction (VoteTx or DelayedVoteTx) to the vendor 300, a direct link between the respondent 200 and the answer is established. Anonymity can disappear because of exposure. Therefore, a group signature may be used to ensure anonymity.

Group signatures are a class of cryptographic protocols that ensure secure group membership relationships without disclosing the signature's identity. A group signature consists of a set of public keys (Pub ₁ , Pub ₂ , ??, Pub _n ) and a private key (Priv _i ) corresponding to one of the corresponding public keys. A group signature (GS(Privi, Pub1, ??, Pubn)(bytes)) is a string of bytes (bytes) that corresponds to one of the public keys (Pub ₁ , Pub ₂ , ??, Pub _n ) and a private key (Priv _i) . ), but it is not disclosed by which. The validity of the signature can be verified if the signature is constructed by a private key corresponding to one of the public keys.

The responder 200 may read random transactions (tx ₁ , ??, tx _n ) recorded in the blockchain 500 and extract public keys (Pub ₁ , ??, Pub _n ) of other respondents. n may be about 20 or less, for example. The responder 200 adds its own transaction tx to the random transactions tx ₁ , ??, tx _n , shuffles these transactions, and provides them to the vendor 300 .

The reward request provided to the vendor 300 includes the wallet address (dst) to provide the reward, the shuffled transaction set (tx ₀ , tx ₁ , ??, tx _n ), the wallet address and transaction set to provide the reward, and the responder's It may include a group signature using a private key (sign=GS(Priv _V , Pub _V , Pub1, ??, Pubn)(hash(dst||tx0, ??, txn)))).

The vendor 300 verifies the set of transactions (tx ₀ , tx ₁ , ??, tx _n ) included in the claim, respectively, and checks whether the transactions are included in the same survey, while the public key ( Extract Pub ₀ , ??, Pub _n ) to verify the group signature (GV(hash(dst, txs), sign, {Pub ₀ , ??, Pub _n }).

Through this process, the vendor 300 can confirm that the respondent 200 has participated in the survey through a transaction and provide a reward without knowing the actual answer of the respondent 200 at all.

The present invention can also be implemented as computer readable codes on a computer readable recording medium. A computer-readable recording medium includes all types of recording devices in which data that can be read by a computer device is stored. Examples of computer-readable recording media include hard disks, ROMs, RAMs, CD-ROMs, hard disks, magnetic tapes, floppy disks, and optical data storage devices. It also includes what is implemented in the form of.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. you will be able to understand Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

100: Issuer 200: Responder
300: vendor 400: survey application

Claims (10)

Creating a survey and recording it on the blockchain;
receiving data for identification of the respondent from a respondent participating in the survey, generating a survey token signed with an issuer's private key, and providing it to the respondent;
providing a survey token signed with the respondent's private key along with survey results to the blockchain as a transaction; and
Including verifying that the transaction is valid, recording it in the blockchain, and aggregating the survey results,
Survey method using survey token and blockchain. According to claim 1,
The survey includes an open survey,
Generating the survey token and providing it to the respondent,
Generating a survey token using a result of signing the hash of the respondent's public key with the issuer's private key,
Survey method using survey token and blockchain. According to claim 2,
The step of providing the survey token signed with the respondent's private key together with the survey results to the blockchain as a transaction,
Including providing a transaction generated by signing the transaction data including the survey token with the respondent's private key to the blockchain,
Survey method using survey token and blockchain. According to claim 1,
The survey includes an anonymous survey,
The step of receiving data for identification of a respondent from a respondent participating in the survey, generating a survey token signed with an issuer's private key, and providing the survey token to the respondent,
Receiving a hash of a public key of a responder blinded with a nonce together with data for identification of the responder,
And providing the respondent with a survey token generated by signing the blinded hash with the issuer's private key.
Survey method using survey token and blockchain. According to claim 4,
After providing the survey token to the respondent,
Further comprising the responder unblinding the survey token with the nonce.
Survey method using survey token and blockchain. According to claim 1,
The data for identification of the respondent includes metadata of the respondent,
The survey token is a puzzled survey token containing information about the metadata,
Survey method using survey token and blockchain. According to claim 6,
The survey includes an open survey,
The puzzled survey token includes a result of encrypting an internal database address in which the metadata is stored.
Survey method using survey token and blockchain. According to claim 6,
The survey includes an anonymous survey,
The step of receiving data for identification of a respondent from a respondent participating in the survey, generating a survey token signed with an issuer's private key, and providing the survey token to the respondent,
A survey generated by receiving a package including a hash of the respondent's public key blinded with a nonce and metadata of the respondent from the respondent, and signing the blinded hash and metadata with the private key of the issuer. Including providing a token to the responder,
Survey method using survey token and blockchain. According to claim 1,
The step of verifying that the transaction is valid, recording it in the blockchain, and aggregating the survey results,
verifying, with the issuer's public key, a survey token signed with the respondent's private key included in the transaction;
Survey method using survey token and blockchain. According to claim 1,
providing a result of providing the signed survey token as a transaction to a blockchain to a vendor as a result of the survey; and
Further comprising the step of verifying the evidence of participation in the questionnaire survey and providing a reward to a respondent whose verification has been completed.
Survey method using survey token and blockchain.

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