KR100362603B1 - An Electronic Voting Method - Google Patents

Abstract

The present invention relates to an electronic voting method using an encryption protocol to prevent fraud that may occur during a voting process, the first process for each voter to generate an individual session ID to register the voter information, and the first process A second process of confirming the information registered by the member and conducting an electronic voting, a third process of verifying and counting the voting information according to the second process by the Election Commission (hereinafter referred to as "the NEC") and the polling place; And a fourth process of publishing an aggregate result according to the third process.

Description

Electronic Voting Method

The present invention relates to an electronic voting method, and more particularly, to an electronic voting method using an encryption protocol to prevent fraud that may occur during a voting process.

The current voting method is performed as shown in FIG. The list of voters produced by the municipality and the ballots produced by the Election Commission are provided to the polling places (A, B), and the NEC sends voting instructions to each voter (C). On the date of voting, the voter goes to the polling place with his ID and verifies that he is a valid voter. Thereafter, a vote is made according to a predetermined procedure and placed in the ballot box (D). At the time of voting deadline, each polling place will move the ballot box to the counting booth and count the results (E). This type of voting has the precondition that the voter must vote directly at the polling place. This is a way of making the list of voters, because there is no way to prevent double voting if it is plural. Therefore, the current voting method was considered cumbersome when the weather was bad or when personal urgent business had to be made to move out of his or her district. However, as open networks such as the Internet are rapidly developing, if the voting can be applied electronically, the inconvenience of the current voting method can be solved. In other words, since it is possible to vote without having to be concerned with the place or the weather, the troublesomeness can be improved, and the voting and counting of the ballots is electronic, which is a very efficient method in terms of time and cost.

These electronic voting schemes come in many forms. The general progress of the electronic voting takes place as shown in FIG. 2. The process of sending the list of electors from the local government to the NEC (S1), the process of sending notices to the voters from the NEC (S2), the certification and voting process of each voter (S3), and the voting results from the electronic polling station And the process of transmitting the voting result to the NEC (S4), and the process of presenting the voting result to the public database by the NEC (S5).

Secret voting is difficult to guarantee if the voter's correlation with the voting value is exposed. This feature makes it difficult for users to keep safe from voting and selling. In order to prevent this, various types of methods have been proposed since a new method called blind signature has been proposed. The concealed signature method used in electronic voting can be largely divided into an RSA based method and an ElGamal based method using discrete algebra. They also take a message-resilient approach. This is because the data itself to be signed by the NEC and the polling place is the voter's identifier, which is an important means of confirming whether or not to vote on the day of voting.

D. Chaum proposed a secret signature scheme that keeps the contents of the other message confidential and signed based on the RSA cipher. For example, if A wants to sign B the message m, but doesn't want to tell m, using a hidden signature allows A to get a signature on B's m.

The basic requirements for this content concealment signature are as follows:

Message content should not be exposed to signers.

· Even after the messages and signatures have been exposed, the relationship between the message and the person receiving them must be untraceable.

The content concealment signature using RSA ciphers satisfying these conditions is as follows. First, let's say A wants to get a signature while concealing message m from B. Let's say B's public key is (e, n) and the secret key is (d, n).

(1) A generates a random number R and sends it to B with C = mr ^e mod n calculated.

(2) B calculates the signature C ^d = (mr ^e ) ^d mod n for the received C and presents it to A.

(3) A calculates S = C ^d / r = m ^d r ^ed / r = m ^d mod n to obtain S as the signature for message m in B.

In this case, B is the signing authority and, in the case of electronic voting, it is the NEC. The signature is also a content hidden signature because the signer encrypts the message and sends it to B, resulting in a signature that B does not know the content of the signature.

Meanwhile, the (k, n) -Threshold Secret Sharing technique is performed between a trusted distributor who distributes partial information about secrets to n participants and the other n participants. Here, a group of participants smaller than k cannot get any information about the secret, but at least a group of k participants can compute the secret in the polynomial.

For example, if we want a (3, n) -threshold technique with k = 3, which requires three participants to reconstruct M, we create a second-order polynomial of k-1 order.

F (x) = (ax ² + bx + M) mod p

Where p is a random prime number greater than the other coefficients. Coefficients a and b are chosen randomly. The coefficients a and b remain secret only during the distribution process and are discarded after each participant's partial secret, shadow, is distributed. M is the message and prime p is public. The shadow is obtained by obtaining the polynomial value at n different points as follows.

k _i = F (x _i )

The first shadow k ₁ is the result of substituting x = ₁ in the polynomial and the second is the result of substituting x = 2. Since the quadratic polynomial has three unknown coefficients a, b, and M, three shadows can be used to determine three unknown coefficients.

The following is a brief description of the current status of domestic and foreign electronic voting research. In 1985, Koyama of Japan proposed a secure anonymous voting method using RSA public key cryptography. However, this method cannot prevent misconduct by the NEC or by a collusion between the NEC and a third party.

In 1986, Cohen and Benaloh proposed a voting scheme to protect voters' privacy by applying interactive zero-knowledge proof or Secret Sharing, respectively, in the rth redundant cryptosystem. However, Benaloh's approach has the advantage of less traffic to the center. An electronic voting protocol that improved Benaloh's method was proposed by Sakai, Murakami, et al. In 1990, and it is possible to monitor fraud more effectively in the way of secret ballot protection.

D. Chaum et al. Proposed a ballot method that guarantees anonymity using hidden signatures with only one member, but could not provide voter equity. Since then, Asano et al. Proposed a method that satisfies the fairness of voters by using bulletin boards with hidden signatures in communication.

Park Chun-sik, proposed in 1993, assumes an anonymous communication channel. In other words, it is trying to prevent the NEC's fraud by organizing it so that all voters can know when the vote is wrong. However, if the NEC commits more than half of the fraud, there is no way to confirm the fraud, and it is not possible to say that it has secured complete safety because it is possible to exercise the right of the non-registrant to vote through a third party. In addition, the Sako method proposed in 1994 proposed an efficient MIX type electronic voting method using partially compatible homomorphism.

In 1996, Niemi-Renvall pointed out the possibility of buying and selling voting, and proposed a countermeasure. In other words, by generating the voter's secret value when generating the voter's identifier that is shown in the results of the voting, he proposed a way for the third party to prove that the voter is his or her identifier. However, this method has a problem in that there is no countermeasure if the voter is asked for the identifier without checking the result of the vote.

In addition, the CFSY (Cramer-Franklin-Schoenmaker-Yung) method secures fairness through the public board method, and adopts a secret channel method to prevent third-party eavesdropping and tampering. At the same time, it is a way of maintaining secrecy to ensure unity for anyone except voters. However, it is impossible to prevent the voting and selling of voters by voting on behalf of the voting traders, and there is no anti-corruption measure for unregistered voters because the safety of the whole system depends on the NEC.

Conventional electronic voting schemes as described above have problems in preventing voting and selling, ensuring voter confidentiality, and preventing the NEC.

An object of the present invention is to provide an electronic voting method that can reduce the manpower, time and cost required for voting and counting which are pointed out as a problem in the existing voting method, and can provide safety and convenience to voters.

Another object of the present invention is to provide an electronic voting method that can prevent the sale of voting and electoral commission.

It is still another object of the present invention to provide an electronic voting method that can guarantee the confidentiality of voters.

In order to achieve the above objects, the present invention provides a first process of generating individual session IDs through a hidden signature to register voter information so that each voter can be identified from others, and the information registered by the first process. A second process of confirming and performing an electronic voting, a third process of confirming and counting voting information according to the second process at a NEC and a polling place, and a fourth process of publishing a counting result according to the third process; Characterized in that made.

Detailed features of the electronic voting method according to the present invention is that it can be divided into a normal mode and a security mode for the prevention of voting and selling in the voting stage, the verification stage and the publication stage.

1 is a configuration diagram briefly showing a conventional general election method,

2 is an operation example of a general electronic voting method,

3 is a flowchart illustrating an operation procedure of the electronic voting method according to the present invention;

4 is an exemplary view showing the registration progress procedure of FIG. 3 in detail;

5 is a flowchart illustrating a voting procedure of FIG. 3 in detail;

6 is a flowchart illustrating the verification procedure of FIG. 3 in detail.

Hereinafter, the present invention will be described with reference to the accompanying drawings. First, the requirements of the electronic voting method that can be implemented by the present invention will be described.

First, what is usually required

① Confidentiality: Only the parties know the voter's response.

② Unity of Voting Rights: One voter has only one vote.

③ Voting Rights Certification: Only those who have the right to vote may vote.

4. Equity: No one can determine his or her own voting result from another person's voting result.

⑤ Impossible forgery: It is impossible to change the voting result by a third party.

⑥ Accuracy: The count of voting results must be accurate.

Second, requirements for preventing electronic voting

① The voter must be able to check the result of his vote.

② The third party can never confirm the result of the vote without the help of the voter.

③ The NEC cannot match the voter with the contents of the vote.

(4) The NEC is independent and shall not commit any fraud related to the vote.

3 is a flow chart showing the overall flow of the present invention. The registration step (S10) that the voter authenticates himself from the NEC and the polling place through the registration process, the voting step (S20) of confirming that the voter is a valid voter in the polling place and performing the voting, and the information provided by each voter at the NEC and the polling place Confirmation step (S30) of confirming the result through, the confirmation step is made of a publication step (S40) to announce the counted vote results through the procedure.

In the present invention, two votes per person are made and a secure hash function and public key encryption technique are applied to inform the seller of both the voter's own identifier and the result of the vote. It is possible to prevent trafficking, and to strengthen the function of the polling station to monitor the fraud that the NEC can commit when it collects.

Symbols displayed in the present invention are defined as follows.

R _i1 , r _i2 : Hidden signature secret coefficients (r _i1 * r _i1 '= 1 mod n, r _i2 * r _i2 ' = 1 mod n)

A ₁ , A ₂ , ... A _n : NEC

V _i : Voter i (i = 1, 2, ..., n)

A _s , A _p : NEC's private and public keys

A _sj , A _v : Distribution secret keys and public key for voting confirmation by the NEC (using Secret Sharing, j = 1, 2, ..., k)

G _s , G _p : Private and public keys of the polling place

V _i1 , v _i2 : Two votes the voter can choose from (only one of them is registered when counting)

R _i1 , R _i2 : random numbers generated by voters

ID _i : Session ID of voter i

H: one-way hash function

H (Sig _i ): hashed signature of voter i

Since the present invention relates to an electronic voting method, in the following description, the Election Commission (hereinafter referred to as the "Election Commission") and the "voting booth" mean each electronic voting management server, and the "vote" through a communication means such as the Internet. It refers to an operation performed in a computer of a plurality of clients that can transmit and receive data in a computer-readable form by accessing a server of the NEC and a polling place. Therefore, the action by each operating entity takes place through each server and computer, and the result is a computer-readable data format. First, the registration step S10 will be described in detail. Figure 4 is a flow chart illustrating in detail the registration step of the electronic vote according to the present invention. The NEC identifies the voters, creates a list of voters, and provides them to the voters and polling places. (S11 course)

Each voter authenticates himself and herself through the registration process and registers a random session ID. The voter selects the secret signature secret coefficients r _i1 and r _i2 to hide the session ID and send it to the NEC and polling place. That is, r _i1 (ID _i ) is generated and transmitted to the NEC, and r _i2 (ID _i ) is generated and registered at the polling place.

On the transmitted data, the NEC jointly authenticates, signs with a representative secret key, and transmits it to the voter. The polling station also authenticates, signs with its private key, and provides it to the voter. A _s (r _i1 (ID _i )) at the NEC and G _s (r _i2 (ID _i )) at the polling place to the voter (step S13).

The voter will verify the signatures received from the NEC and the polling place. The voter removes his secret count to obtain his identifier, S _A , signed by the NEC and S _G , signed by the polling place. r _i1 '(A _s (r _i1 (ID _i ))) = A _s (ID _i ) = S _A, r _i2 ' (G _s (r _i2 (ID _i )) = G _s ((ID _i )) = S _G (S14 course)

After that, the signature is checked using the public key A _p of the NEC and the public key G _p of the polling place, and it is checked whether its identifier is correctly registered. A _p (S _A ) = A _p (A _s (ID _i )) = ID _i, G _p (S _G ) = G _p (G _s (ID _i )) = ID _i (S15 process)

Voting process (S20) according to the present invention will be described using the flow chart of FIG. When the voting date is reached, the voter physically checks himself in the polling place and performs the voting (S21 process). (S22 process)

First, a case in which the voter selects the general mode will be described as an example. The voter creates his first choice value FIR and dummy value DUM as follows: (v _i1 ∥R _i1 ) = FIR, (ID _i ∥R _i2 ) = DUM (where R _i1 and R _i2 are random values chosen by the voter) (step S23-1)

Then, using the general mode value FIR, dummy value DUM, and the hash value of the voter's signature {H (Sig _i )} to calculate the following. H (FIR∥DUM∥H (Sig _i )) = J (S24-1 course)

The voter concatenates the general mode value FIR, the dummy value DUM and the hash value H (Sig _i ) hashed with his signature and encrypts it with the NEC's public key. A _v (FIR∥DUM∥H (Sig _i )) = E (S25-1 process)

The voter transmits the signatures of the polling place and the committee in conjunction with the cryptographic results. S _A E sends to the NEC and stores S _G J in the DB of the polling place (S26-1 process).

If the voter votes by selecting a security mode as a measure to prevent voting and selling, the process proceeds as follows. The voter generates the primary selection value FIR and the secondary selection value SEC as follows. (v _i1 ∥R _i1 ) = FIR, (v _i2 ∥R _i2 ) = SEC (where R _i1 and R _i2 are random values chosen by the voter) (step S23-2)

Subsequently, the hash value H is used to concatenate the first selection value FIR, the second selection value SEC, and the hash value H (Sig _i ) of the signature. H (FIR∥SEC∥H (Sig _i )) = K (S24-2 process)

The voter concatenates the first-choice FIR, the second-choice SEC and the hash of his signature, H (Sig _i ), with the public key of the NEC. Av (FIR ∥ SEC ∥ H (Sig _i )) = E '(S25-2 course)

The voter transmits the signatures of the polling place and the NEC in conjunction with the cryptographic results. S _A E 'sends the NEC and saves S _G K in the DB of the polling place (step S26-2).

Confirmation step (S30) according to the present invention is as shown in the flow chart of FIG. As in the voting step of Figure 5 is divided into a normal mode and a security mode (S31 process).

If the voter chooses to vote in normal mode, the NEC and the polling place verify the signature with their public key. A _p (S _A ) = ID _i, G _p (S _G ) = ID _i (S32-1 process)

The NEC decrypts the voting information with their distributed secret keys and aggregates the results. A _sj (E) = A _sj (A _p (FIR∥DUM∥H (Sig _i ))) = FIR∥DUM∥H (Sig _i ) (S33-1)

The NEC sends the final counting result to a private database that only the polling place can access and temporarily stores it (step S34-1).

The polling place checks the final counting result collected by the polling place and the result sent by the NEC to confirm the contents match (S35 process), and notifies the NEC to the comparison result. (S36 process)

If the comparison result according to step S35 does not coincide with the final counting result (step S37), the NEC transmits the result of the vote encrypted by using the public key of the polling place (step S38).

The polling station checks the voting information received from the NEC with its private key and takes the hash. G _s (G _p (FIR ∥ DUM ∥ H (Sig _i ))) = FIR ∥ DUM ∥ H (Sig _i ) (S39 process)

It then compares the contents with those stored in a private database. H (FIR∥DUM∥H (Sig _i )) = J (S40 course)

If the result is the same, it is regarded as a legitimate vote value, and R _i1 is omitted, and v _i1 and H (Sig _i ) are concatenated and counted. In order not to expose the voter's voting result to the third party, hashing ID _i ∥R _i2 is connected. ID _i v _i1 H (Sig _i ) H (ID _i R _i2 ) (S41 process). If the results do not match, the NEC will request the voting results again to perform the process again from S38.

If the voter selects the security mode to vote, the verification process (S30) is performed as follows. NEC and polling stations verify signatures with their public keys. A _p (S _A ) = ID _i , G _p (S _G ) = ID _i (step S32-2)

The NEC decrypts the voting information with their distributed secret keys and aggregates the results. A _sj (E ') = A _sj (A _p (FIR ∥ SEC ∥ H (Sig _i ))) = FIR ∥ SEC ∥ H (Sig _i ) (S33-2 process)

The NEC temporarily stores the final counting result by sending it to a private database that only the polling place can access (step S34-2).

The polling place compares the final counting results collected by the polling places with the results sent by the NEC (S35 process) and notifies the NEC of the contents match (S36 process).

As in the general mode, if the final counting result does not match (step S37), the NEC encrypts and sends the ballot result with the public key of the polling place (step S38).

The polling station checks the voting information received from the NEC with its private key and takes the hash. G _s (G _p (FIR ∥ SEC ∥ H (Sig _i ))) = FIR ∥ SEC ∥ H (Sig _i ) (S39 process)

Compares with what is stored in a private database. H (FIR∥SEC∥H (Sig _i )) = K (S40 process) If the same result is obtained, the result is recognized. (S41 process)

When the voter chooses the normal mode, instead of using R _i1 and then concatenating v _i1 and H (Sig _i ) for aggregation, v _i2 enters the aggregation. Then write the result as follows: ID _i ∥v _i1 H (ID _i ∥H (Sig _i ) ∥H (v _i2 ∥R _i2 )). At this time, the result of the first choice shall not be the same as the result of the second choice and shall not expose the voter's vote result from the third party.

On the other hand, after the verification and counting process of the voting result is completed, the process of publishing the result (S40) is as follows. The NEC saves the voters' votes and publishes them on the public board. At this time, it is divided into the normal mode and the security mode. If the general mode is selected, ID _i ∥v _i1 ∥H (Sig _i ) ∥H (ID _i ∥R _i2 ) is stored, and the voting value v _i1 is calculated. do. If the security mode is selected, ID _i ∥v _i1 ∥H (ID _i ∥H (Sig _i ) ∥H (v _i2 ∥R _i2 )) is stored, and the voting value v _i2 is the counting result. At this time, the number of votes of the candidates is counted and announced according to the voter's vote value on the public board.

Each voter can check the publicity on the public board to ensure that his or her vote has been reflected. Voters who choose normal mode need only check v _i1 , and voters who have used voting prevention measures choose a secure mode, so they combine their identifiers, secondary choices, and random numbers they generate. By comparing one value with the result of the vote, we confirm that our vote result v _i2 has been counted. ID _i ∥v _i1 ∥H (ID _i ∥H (Sig _i ) ∥H (v _i2 ∥R _i2 )) ==> H (ID _i ∥H (Sig _i ) ∥H (v _i2 ∥R _i2 ))

As described above, the present invention is safer than the conventional voting method, saves money, manpower, time, and can vote without having to be weather or place, thus improving not only the turnout rate but also our lives. It is effective to provide the convenience and to contribute to the development by establishing the basic concept of the encryption protocol upon which the proposal of the efficient and secure electronic voting method is based. In addition, the present invention satisfies all of the general requirements, requirements for preventing voting and selling, and requirements for preventing the fraudulent elections, as described in the technical problem, and sufficiently covers the security elements required by the electronic voting method.

The technical spirit of the present invention has been described above with reference to the accompanying drawings. In addition, it is obvious that any person skilled in the art may make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (9)

A computer-readable data can be transmitted and received by accessing the servers of the Election Commission and the Polling Place through electronic voting management servers (hereinafter referred to as servers) of the Election Commission and the Polling Place, and through communication means such as the Internet. An electronic voting method using an electronic voting system comprising a plurality of voter computers (hereinafter referred to as voters); A first step of generating a computer-readable form of voter roster data using a server of an election management committee and transmitting the data to a computer of each voter and a plurality of polling stations accessible through a communication means such as the Internet; A second step in which the voter receiving the voter roster data from the NEC generates a session ID in the form of computer-readable data using a secret signature secret coefficient other than the real name, and transmits the session ID to the NEC and the server of the polling place; A third step of authenticating the received session ID data using the server of the NEC and the polling place, and forming the data signed by each secret key and transmitting the data to the voter computer; A fourth step in which each voter removes his secret coefficient from the data received from the server of the NEC and the polling place to extract its identifier including the NEC signature and the identifier information including the signature of the polling place; A registration step (A) comprising a fifth step of confirming the voter's identifier registration by confirming the signature of each voter using the information extracted through the fourth step using the public key of the NEC and the public key of the polling place; When the voter sets the general mode in the mode setting divided into the general voting mode and the security mode to prevent the voting traffic, A 6-1 step in which the voter generates a first selection value and a dummy value in the form of computer-readable data using random values; A seventh step of obtaining a hash function for which the voter hashes the voter's signature, the first selection value, and a dummy value; A step 8-1 in which the voter concatenates the voter's first selection value and the dummy value generated in step 6-1 and the hash value of the voter's signature and encrypts it with the public key of the NEC; A 9-1 step in which the voter generates data obtained by concatenating the NEC's signature with the cipher result generated in the 8-1st step and transmits the data to the NEC server; A general mode voting process (B-1) comprising a step 10-1 of storing data in a database connected to the polling place server, the data concatenating the polling place signature with the hash function result value generated in the step 7-1; ; A step 11-1 of checking the signature information included in the voting information data using the respective public key at the NEC and the polling place; 12-1 step of decrypting the voting information with the respective secret key in the NEC and the polling place to aggregate the results; Step 13-1 of the NEC transmitting the final counting result to a private database accessible only to the polling place server; A step 14-1 of checking, at the polling place, whether or not the final result aggregated by the polling place according to the step 12-1 coincides with the final counting result provided by the NEC through the step 13-1; A general mode election result processing process (C-1) including a fifteenth step of informing the election committee of the polling place according to the step 14-1; When the voter sets the security mode in the mode setting divided into the general voting mode and the security mode for preventing the voting traffic, A 6-2 step in which the voter generates the first selection value Fir and the second selection value Sec in the form of computer-readable data by using the random value; A step 7-2 in which a voter calculates a hash function having the data value hashing the voter's signature, the first selection value (Fir), and the second selection value (Sec) as parameters; An eighth voter concatenating the voter's primary selection value (Fir), the voter's primary selection value (Sec), and the voter's signature hashed with the public key of the NEC; -2 steps; A step 9-2 in which the voter generates data obtained by concatenating the NEC's signature with the cipher result generated by the step 8-2 and transmits the data to the NEC server; Security mode voting process (B-2) comprising the step 10-2 of storing the data concatenated with the signature of the polling place to the hash function result value generated in step 7-2 in a database connected to the polling place server and ; 11-2 step of confirming the signature information contained in the ballot information data provided with the respective public key by the NEC and the polling place; Step 12-2, in which the election committee and the polling place decrypt the voting information with the respective secret keys and aggregate the result; Step 13-2 of sending the final counting result to a private database accessible only to the polling place by the NEC; A 14-14 step of checking, at the polling place, whether or not the final result aggregated by the polling place according to the step 12-2 and the final aggregation result provided by the NEC through the step 13-2; And an electronic voting method (C-2) comprising a security mode election result processing step (C-2) comprising a step 15-2 of notifying the NEC of the verification result according to the step 14-2 at the polling place. delete delete delete delete delete The method of claim 1; If the notification result is negative in the step (15-1, 15-2) of notifying the NEC at the polling place during the process of processing the election results for each mode, A sixteenth step in which the NEC encrypts the voting result with the public key of the polling place and sends it to the polling place; A seventeenth step in which the polling place checks the voting information received through the sixteenth step with the secret key of the polling place and takes a hash; An eighteenth step of determining whether or not the polling place matches the result of the seventeenth step with the voting information stored in the database of the polling place; If it is recognized as a valid vote value as a result of step 18, the first vote value selected by the voter, the voter's signature hash value, and the voter's session ID and the voter's random number of hash values are concatenated. Electronic voting method characterized in that a series of processes including the nineteenth step is added. delete delete