TWI574215B - Point-to-point electronic trading system, method and its computer program products - Google Patents

Description

Peer-to-peer electronic trading system, method and computer program product thereof

The invention relates to a technical means of electronic transaction, in particular to a technical means for interactively generating a transaction voucher during a transaction process, and excluding a verification connection with a third-party transaction authentication center.

The current electronic trading system generates undeniable transaction verification information when trading between buyers and sellers. Therefore, both parties need to connect to the third-party transaction certification center during the transaction, and retain the transaction verification information in the third party after completing the transaction. In the event of a transaction dispute in the future, arbitration may be conducted by means of transaction verification information.

In the above-mentioned technical solution, the third-party transaction authentication center will inrush a large number of verification requests, which may result in the third-party transaction authentication center not functioning properly. In this solution, if the third-party verification cannot be obtained at the time of the transaction, The transaction cannot be completed correctly, and thus the overall transaction process is delayed, which seriously affects the development of electronic transactions.

In summary, how to provide a technical means that can be verified by a third-party transaction authentication center during transaction is a technical solution that needs to be solved in the field.

In order to solve the problems disclosed above, the object of the present invention is to provide a technical means for verifying the connection in the transaction and third party authentication.

To achieve the above object, the present invention proposes a peer-to-peer electronic transaction system. The system consists of the buyer and the seller. The two parties obtain the buyer transaction content (BTC) and the seller transaction content (STC) at the time of the transaction, and the seller receives the seller's transaction authentication content (STAC) from the buyer at the time of verification, and decrypts it via the private key to obtain the buyer of the plaintext. Transaction content (BTC) and seller's transaction verification content (STVC) of the signature ciphertext; the buyer receives the buyer's transaction authentication content (BTAC) from the seller at the time of verification, and decrypts it via the private key to obtain the seller of the plaintext. The transaction content (STC) and the buyer's transaction verification content (BTVC) of the signature ciphertext; wherein the buyer and the seller respectively verify the buyer transaction content (BTC) and the seller transaction content (STC), and the verification failure on either side is judged as transaction failed. The buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively encrypted by the seller private key and the buyer private key as an undeniable basis.

To achieve the above object, the present invention provides a peer-to-peer electronic transaction method comprising the steps of: the buyer and the seller both obtain buyer transaction content (BTC) and seller transaction content (STC) at the time of transaction. Then, the seller receives the seller's transaction authentication content (STAC) of the ciphertext from the buyer at the time of verification, and decrypts through the private key to obtain the plain buyer transaction content (BTC) and the seller's transaction verification content of the signature ciphertext (STVC). ). Furthermore, the buyer receives the buyer transaction authentication content (BTAC) of the ciphertext from the seller at the time of verification, and decrypts through the private key to obtain the seller's transaction content (STC) of the plaintext and the buyer transaction verification content of the signature ciphertext ( BTVC). Furthermore, the buyer and the seller each verify the buyer transaction content (BTC) and the seller transaction content (STC), and if the verification fails on either side, the transaction is determined to be a failure. Among them, the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively encrypted by the seller private key and the buyer private key as an undeniable basis.

In order to achieve the above object, the present invention proposes an electric power applied to point-to-point electronic transactions. The brain program product, when the computer device loads and executes the computer program product, can complete the steps as described in the foregoing method.

In order to achieve the above object, the present invention provides a buyer-side electronic transaction method applied to a peer-to-peer electronic transaction system, which is applied to an electronic device at a buyer end, and includes both a buyer side and an external seller side to obtain buyer transaction content (BTC) at the time of transaction and Seller Transaction Content (STC). The seller receives the seller's transaction authentication content (STAC) of the ciphertext from the buyer at the time of verification, and decrypts through the private key to obtain the plain buyer transaction content (BTC) and the signature ciphertext seller transaction verification content (STVC). Triggering the buyer to receive the buyer's transaction authentication content (BTAC) from the seller at the time of verification, and decrypting through the private key to obtain the seller's transaction content (STC) and the buyer's transaction verification content (BTVC) of the signature ciphertext. . And the buyer and the seller each verify the buyer's transaction content (BTC) and the seller's transaction content (STC), and if the verification fails on either side, it is judged as the transaction failure. Among them, the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively encrypted by the seller private key and the buyer private key as an undeniable basis.

To achieve the above object, the present invention provides a buyer-side computer program product for use in a peer-to-peer electronic transaction system. When the computer device loads and executes the computer program product, the steps described in the buyer-side electronic transaction method can be completed.

In order to achieve the above object, the present invention provides a seller-side electronic transaction method applied to a point-to-point electronic transaction system, which is applied to an electronic device at a seller end, and includes the following steps: First, the external buyer and the seller are both engaged in the transaction. Get buyer transaction content (BTC) and seller transaction content (STC). Then, the seller is triggered to receive the seller's transaction authentication content (STAC) of the ciphertext from the buyer at the time of verification, and decrypted by the private key to obtain the buyer transaction content (BTC) of the plaintext and the seller transaction verification of the signature ciphertext. Content (STVC). Then the buyer The buyer transaction authentication content (BTAC) of the ciphertext is received from the seller at the time of verification, and decrypted by the private key to obtain the seller's transaction content (STC) of the plaintext and the buyer transaction verification content (BTVC) of the signature ciphertext. Furthermore, the buyer and the seller each verify the buyer transaction content (BTC) and the seller transaction content (STC), and if the verification fails on either side, the transaction is determined to be a failure. The buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively encrypted by the seller private key and the buyer private key as an undeniable basis.

To achieve the above object, the present invention provides a vendor-side computer program product for use in a point-to-point electronic transaction system. When the computer device loads and executes the computer program product, the steps described in the aforementioned seller-side electronic transaction method can be completed.

In summary, the peer-to-peer electronic transaction system, method and computer program product thereof of the present invention can complete the undeniable verification procedure by exchanging and verifying the transaction credential information encrypted by the private key during the transaction, and can be used at the time of transaction. There is no need to verify the connection with a third-party transaction authentication center.

S101~S113‧‧‧Steps

F101~F106‧‧‧Steps

F201~F203‧‧‧Steps

F301~F304‧‧‧Steps

1‧‧‧ buyer

2‧‧‧Seller

3‧‧‧ Third Party Transaction Certification Center

1 is a schematic diagram of a point-to-point electronic transaction system in accordance with an embodiment of the present invention.

2 is a schematic diagram of a transaction verification process of the present invention.

FIG. 3 is a schematic diagram of a process for generating transaction authentication information by the seller end of the present invention and transmitting the information to the buyer.

4 is a flow chart of decryption and comparison of buyers and sellers of the present invention.

FIG. 5 is a flow chart of verification of a third party transaction center of the present invention.

Specific embodiments will be described below to illustrate embodiments of the invention, but It is not intended to limit the scope of the invention as claimed.

Please refer to FIG. 1, which is a schematic diagram of a peer-to-peer electronic transaction system of the present invention. The system includes a buyer side 1 and a seller side 2, and a third party transaction authentication center 3 that is connected only when arbitration or key is obtained. Both the buyer side 1 and the seller side 2 mentioned above obtain the buyer transaction content (BTC) and the seller transaction content (Seller Transaction Content, STC) at the time of transaction. Both parties are verified according to the process shown in Figure 2, and the process is described as follows:

S101: The seller terminal 2 receives the Seller Transaction Authentication Content (STAC) of the ciphertext from the buyer terminal 1 at the time of verification.

S102: decrypting by a private key to obtain a plaintext transaction content (BTC) of the buyer and a seller transaction verification content (STVC) of the signature ciphertext;

S103: Does the seller determine whether the buyer's transaction content (BTC) is the same as its own transaction content (STC)? If yes, execute S104; if not, execute S105.

S104: Determine that the transaction is completed.

S105: If either party fails, the transaction is judged to be unsuccessful.

S111: The buyer 1 receives the Buyer Transaction Authentication Content (BTAC) of the ciphertext from the seller terminal 2 upon verification.

S112: decrypting through the private key to obtain the seller's transaction content (STC) of the plaintext and the buyer transaction verification content (BTVC) of the signature ciphertext.

S113: Is the buyer transaction content (BTC) the same as the seller transaction content (STC)? If yes, execute S114; if not, execute S105.

End

The aforementioned buyer transaction verification content (BTVC) and seller transaction verification content (STVC) are respectively encrypted by the seller private key and the buyer private key as an undeniable basis.

The aforementioned third party transaction authentication center 3 provides a public key to the buyer side 1 to form a buyer transaction verification content (BTVC), and provides a public key to the seller to form a seller transaction verification content (STVC), wherein the third party transaction authentication center 3 arbitrates Under the operation, the buyer terminal 1 and the seller terminal 2 acquire, decrypt and compare the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) to perform the arbitration operation.

Compared with the prior art, the third party performs verification at the time of transaction, and the present invention holds the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) by the buyer side 1 and the seller side 2, and is in the process of In the event of a dispute, the content will be verified before being delivered to the third party transaction authentication center 3 for arbitration. Therefore, the buyer 1 and the seller 2 of the present invention exclude the connection with the third party for verification at the time of transaction.

In another embodiment, the present invention further provides a peer-to-peer electronic transaction method, the method comprising the following steps:

M101: Both the buyer 1 and the seller 2 acquire the buyer transaction content (BTC) and the seller transaction content (STC) at the time of the transaction;

M102: The seller terminal 2 receives the seller transaction authentication content (STAC) of the ciphertext from the buyer terminal 1 at the time of verification.

M103: The buyer 1 decrypts by the private key to obtain the plain buyer transaction content (BTC) and the signature ciphertext seller transaction verification content (STVC).

M104: The seller terminal 2 receives the buyer transaction authentication content (BTAC) of the ciphertext from the buyer terminal 1 at the time of verification, and decrypts through the private key to obtain the seller's transaction content (STC) and signature in plaintext. Cipher's Buyer Transaction Verification (BTVC).

M105: The buyer and the seller respectively verify the buyer transaction content (BTC) and the seller transaction content (STC), and if the verification fails on either side, it is judged as the transaction failure. Among them, the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively encrypted by the seller private key and the buyer private key as an undeniable basis.

In the foregoing method, a third party transaction authentication center 3 is further included. The aforementioned third party transaction authentication center 3 provides a public key to the buyer side 1 to form a buyer transaction verification content (BTVC), and further provides a public key to the seller to form a seller transaction verification content (STVC), wherein the third party transaction authentication center 3 Under the arbitration operation, the buyer terminal 1 and the seller terminal 2 acquire, decrypt and compare the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) to perform the arbitration operation.

In another embodiment, the present invention further provides a computer program product for point-to-point electronic transaction. When the computer device loads and executes the computer program product, the steps described in the foregoing peer-to-peer electronic transaction method can be completed.

In another embodiment, the present invention further provides a buyer-side 1 electronic transaction method applied to a point-to-point electronic transaction system, which is applied to the electronic device of the buyer terminal 1, and includes the following steps:

M201: Both the buyer 1 and the external seller 2 obtain the buyer transaction content (BTC) and the seller transaction content (STC) at the time of the transaction;

M202: The seller terminal 2 receives the seller transaction authentication content (STAC) of the ciphertext from the buyer terminal 1 at the time of verification.

M203: The buyer 1 decrypts via the private key to obtain the plain buyer transaction content (BTC) and the signature secret The seller's transaction verification content (STVC).

M204: At the time of verification, the buyer 1 receives the buyer's transaction authentication content (BTAC) of the ciphertext from the seller terminal 2, and decrypts through the private key to obtain the seller's transaction content (STC) of the plaintext and the buyer transaction verification content of the signature ciphertext. (BTVC).

M205: The buyer and the seller respectively verify the buyer transaction content (BTC) and the seller transaction content (STC), and if the verification fails on either side, it is judged as the transaction failure. Among them, the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively encrypted by the buyer private key and the seller private key as an undeniable basis.

In another embodiment, the present invention further provides a buyer computer program product for use in a peer-to-peer electronic transaction system. When the computer device loads and executes the computer program product, the steps described in the aforementioned buyer-side electronic transaction method can be completed.

In another embodiment, the present invention further provides a vendor-side 2 electronic transaction method applied to a point-to-point electronic transaction system. The method is applied to the electronic device of the vendor terminal 2, and includes the following steps:

M301: Both the external buyer 1 and the seller 2 acquire the buyer transaction content (BTC) and the seller transaction content (STC) at the time of the transaction.

M302: At the time of verification, the seller terminal 2 receives the seller transaction authentication content (STAC) of the ciphertext from the buyer terminal 2.

M303: Trigger buyer 1 decrypts via private key to obtain plaintext buyer transaction content (BTC) and signature ciphertext seller transaction verification content (STVC).

M304: The buyer 1 receives the buyer's transaction authentication content (BTAC) of the ciphertext from the seller terminal 2 at the time of verification, and decrypts through the private key to obtain the seller's transaction content (STC) and signature in plaintext. Cipher's Buyer Transaction Verification (BTVC);

M305: The buyer and the seller each verify the buyer's transaction content (BTC) and the seller's transaction content (STC), and if the verification fails on either side, it is judged as the transaction failure. Among them, the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively encrypted by the buyer private key and the seller private key as an undeniable basis.

In another embodiment, the present invention further provides a vendor-side 2 computer program product for use in a peer-to-peer electronic transaction system. When the computer device loads and executes the computer program product, the steps described in the aforementioned vendor 2 electronic transaction method can be completed.

The aforementioned computer program products can be implemented by ASP, C/C++/C#, JAVA, Python, PHP, Perl, etc., but the category of the programming language is not limited thereto.

The present invention further clarifies the operation mode by taking the point-to-point electronic transaction system as an example, but the above-mentioned point-to-point electronic transaction method, computer program product of point-to-point electronic transaction, buyer-side electronic transaction method applied to the point-to-point electronic transaction system, and application to point-to-point electronic The buyer-side computer program product of the trading system, the vendor-side 2 electronic trading method applied to the peer-to-peer electronic trading system, and the vendor-side computer program product applied to the peer-to-peer electronic trading system also have the same technical features and functions.

Please refer to FIG. 3 , which is a schematic diagram of the process of generating transaction authentication information by the seller 2 of the present invention and transmitting it to the buyer 1 .

F101: Buyer 1 will use the Buyer Private Key (SK _b ) to encrypt its BTC as a digital signature to ensure that the BTC is signed by itself and no one can tamper with or falsify. And transmitted to the seller side 2.

B→S: Enc _SKb ( BTC' ) Eq(1)

F102: When the seller 2 receives Enc _SKb ( BTC' ), it first obtains the buyer public key (PK _b of the buyer 1 and decrypts the Enc _SKb ( BTC' ) (BTS'). And whether it is consistent with the self-assessment judgment of the STC, if they are consistent, it forms an undeniable transaction evidence for both parties; if it is inconsistent, it judges that the transaction fails.

S:Dec _PKb ( BTC' )→(BTC ' ) Eq(2)

F103: After the verification is successful, the buyer and the seller can determine the correctness of Enc _SKb ( BTC' ), and then the seller 2 also uses the seller's private key (SK _s ) to use the seller's private key (SK _s ) as the digital signature. Encryption to ensure that the STC has signed it for itself and then transmits it to the buyer.

S→B: Enc _SKb ( STC' ) Eq(3)

F104: Next, the seller 2 obtains the public key PK _{t of the} third party transaction center to _encrypt the Enc _SKb ( BTC' ) and its own Enc _SKb ( STC' ) using the RSA mechanism.

S: BTVC=Enc _PKt ((Enc _SKb ( BTC' )∥(Enc _SKs ( STC' )) Eq(4)

F105 and F106: The seller 2 continues to obtain the PK _{b of the} buyer 1 and uses the message authentication code (MAC) encryption mechanism to generate the MAC, and adds the MAC to the message to ensure the integrity of the message, and finally the message of the encryption completion. Transfer to buyer 1 . The practice of buyer 1 is vice versa.

S: BTAC=MAC _PKb ( STC ∥Enc _PKt ((Enc _SKb ( BTC' ) ∥ (Enc _SKs ( STC ))) Eq(5)

Please refer to FIG. 4, which is a flow chart for the buyer and the seller to transmit the transaction authentication messages to each other, and obtain the BTAC and STAC for decryption and comparison.

F201: After the buyer and the seller use their own SK _b and SK _s to unlock the encrypted MAC, the buyer 1 can obtain the other party's plain text (STC), and the seller can obtain the other party's plain text (BTC).

_{B: Dec SKb BTAC = Dec SKb} (MAC PKb (STC ∥ Enc PKt (Enc SKb (BTC ')) ∥ Enc SKs (STC))))) → (STC∥Enc PKt (Enc SKb (BTC')) ∥ Enc _SKs ( STC )) Eq(6)

S:Dec _SKB STAC=Denc _SKs ( MAC _PKS (BTC∥ Enc _PKt (( Enc _SKs ( STC' ))∥ Enc _SKb ( BTC ))))→(BTC∥ Enc _PKt (( Enc _SKs ( STC' ))∥ Enc _SKb ( BTC ))) Eq(7)

F202 and F203: The buyer 1 uses the taken out STC to check with the BTC. The seller 2 checks the taken out BTC and its own STC to determine whether it is consistent. If they are consistent, the transaction is successful, and there is no need to conduct arbitration through a third-party trading center; if they are inconsistent, they need to be processed by a third-party trading center.

Please refer to FIG. 5, which is a decryption and verification process after the third party transaction center receives the BTVC and the STVC. The relevant instructions are as follows:

F301: Buyer 1 and Seller 2 will transmit the PK _t encrypted message from the third party transaction center to the third party transaction center.

B→TTP: BTVC=Enc _PKt ((Enc _SKb (BTC ' ))∥Enc _SKs (STC))) Eq(8)

S→TTP: STVC=Enc _PKt (( Enc _SKs ( STC' ))∥ Enc _SKb ( BTC )) Eq(9)

F302; After receiving the message transmitted by the buyer 1 and the seller 2, the TTP decrypts the message by using its own private key SK _t .

TTP: Dec _SKt BTVC = Dec _SKt ( Enc _PKt (( Enc _SKb ( BTC' )) ∥ Enc _SKs ( STC ))) → ((Enc _SKb ( BTC' )) ∥ Enc _SKs ( STC )) Eq (10)

TTP: Dec _SKt STVC = Dec _SKt ( Enc _PKt (( Enc _SKs ( STC' )) ∥ Enc _SKb ( BTC ))) → (( Enc _SKs ( STC ' ) ) ∥ Enc _SKb ( BTC ) ) Eq (11)

F303: Next, the third-party trading center obtains the PK _{b of} both parties and the Seller Public Key (PKs) to decrypt the messages of both parties to obtain the undeniable transaction information (STC') and (BTC'). .

TTP: Dec _PKb ( Enc _SKb ( BTC' )) ∥ Dec _PKs ( Enc _SKc ( STC )) → ((BTC ' ) ∥ (STC)) Eq(12)

TTP: (Dec _PKs ( Enc _SKs ( STC ' )) ∥ Dec _PKs ( Enc _SKb ( BTC ) → ((STC ' ) ∥ (BTC)) Eq (13)

F304: When the messages are decrypted into plaintext, you can verify that the party forged the transaction message.

Verification Rule 1-1: If STC' and BTC are inconsistent, it is determined that Buyer 1 falsifies the transaction message.

Verification Rule 1-2: If BTC' and STC are inconsistent, it is determined that Seller 2 falsifies the transaction message.

Verification Rule 2-1: If BTC and BTC' are inconsistent, it is determined that Buyer 1 falsifies the transaction message.

Verification Rule 2-2: If the STC and the STC are inconsistent, it is determined that the Seller 2 falsifies the transaction message.

The detailed description above is a detailed description of one of the possible embodiments of the present invention, which is not intended to limit the scope of the invention, which is not Equivalent implementations or changes shall be included in the scope of the patent in this case.

S101~S114‧‧‧Steps

Claims (10)

A peer-to-peer electronic transaction system includes: a buyer and a seller both obtain buyer transaction content (BTC) and seller transaction content (STC) at the time of transaction, and the seller receives the seller transaction authentication content of the ciphertext from the buyer at the time of verification ( STAC), and decrypted by the private key to obtain the plaintext transaction content (BTC) of the buyer and the seller transaction verification content (STVC) of the signature ciphertext; the buyer receives the buyer transaction authentication of the ciphertext from the seller at the time of verification Content (BTAC), and decrypted by private key to obtain the seller's transaction content (STC) of the plaintext and the buyer transaction verification content (BTVC) of the signature ciphertext; and wherein the buyer and the seller respectively verify the buyer transaction content ( BTC) and the seller transaction content (STC), and the failure of the verification on either side is determined as the transaction failure; wherein the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively determined by the seller private key and the The buyer's private key is encrypted as an undeniable basis. The point-to-point electronic transaction system as claimed in claim 1 further includes a third-party transaction authentication center that provides a public key to encrypt the buyer to form the buyer transaction verification content (BTVC) and provides the public The key is encrypted to form the seller transaction verification content (STVC), wherein the third party transaction authentication center arbitration operation acquires, decrypts, and compares the buyer transaction verification content (BTVC) from the buyer side and the seller side, and the Seller Transaction Verification Content (STVC) for arbitration purposes. The peer-to-peer electronic transaction system of claim 1, wherein the buyer and the seller terminate the connection with the third party for verification at the time of the transaction. A peer-to-peer electronic transaction method includes: the buyer and the seller both obtain buyer transaction content (BTC) and seller transaction content (STC) at the time of transaction; the seller receives the seller transaction authentication content of the ciphertext from the buyer at the time of verification (STAC), and decrypted by the private key to obtain the plain buyer transaction content (BTC) and the seller's transaction verification content (STVC) of the signature ciphertext; the buyer receives the ciphertext buyer transaction from the seller at the time of verification Authenticated Content (BTAC), decrypted by private key to obtain the seller's transaction content (STC) of the plaintext and the buyer's transaction verification content (BTVC) of the signature ciphertext; and the buyer and the seller respectively verify the buyer's transaction content (BTC) And the seller transaction content (STC), and the failure of the verification on either side is determined as the transaction failure; wherein the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively determined by the seller private key and the The buyer's private key is encrypted as an undeniable basis. The point-to-point electronic transaction method as claimed in claim 4, further comprising a third-party transaction authentication center, wherein the third-party transaction authentication center provides a public key to encrypt the buyer to form the buyer transaction verification content (BTVC), and provides the The public key encrypts the seller to form the seller transaction verification content (STVC), wherein the third party transaction certification center arbitration operation obtains, decrypts, and compares the buyer transaction verification content (BTVC) from the buyer side and the seller side, and The seller transactions verify the content (STVC) for arbitration purposes. A computer program product for use in a peer-to-peer electronic transaction. When the computer device loads and executes the computer program product, the steps of any one of claims 4 to 5 can be completed. A buyer-side electronic transaction method applied to a point-to-point electronic transaction system, applied to a buyer The electronic device includes: the buyer and the external seller end obtain the buyer transaction content (BTC) and the seller transaction content (STC) at the time of the transaction; the seller receives the seller transaction of the ciphertext from the buyer at the time of verification The content of the authentication (STAC), and decrypted by the private key to obtain the buyer's transaction content (BTC) of the plaintext and the seller's transaction verification content (STVC) of the signature ciphertext; at the time of verification, the buyer receives the ciphertext from the seller The buyer transaction authentication content (BTAC), and decrypted by the private key to obtain the plain seller's seller transaction content (STC) and the signature ciphertext buyer transaction verification content (BTVC); and the buyer and the seller system respectively verify the buyer transaction content (BTC) and the seller transaction content (STC), and the failure of the verification on either side is determined as the transaction failure; wherein the buyer transaction verification content (BTVC) and the seller transaction verification content (STVC) are respectively determined by the seller private key And the buyer's private key is encrypted as an undeniable basis. A buyer computer program product for use in a peer-to-peer electronic trading system, which can perform the steps as recited in claim 7 when the computer device loads and executes the computer program product. A seller-side electronic transaction method applied to a point-to-point electronic transaction system, applied to an electronic device at a seller end, comprising: an external buyer terminal and the seller side obtain buyer transaction content (BTC) and seller transaction content (STC) at the time of transaction The seller receives the seller's transaction authentication content (STAC) of the ciphertext from the buyer at the time of verification, and decrypts the private transaction key to obtain the plain buyer transaction content (BTC) and the seller's transaction verification content of the signature ciphertext ( STVC); At the time of verification, the buyer's transaction authentication content (BTAC) is received by the seller and received by the seller, and decrypted by the private key to obtain the seller's transaction content (STC) of the plaintext and the buyer transaction verification content of the signature ciphertext ( BTVC); and the buyer and the seller respectively verify the buyer transaction content (BTC) and the seller transaction content (STC), and the failure of the verification on either side is determined as the transaction failure; wherein the buyer transaction verification content (BTVC) And the seller transaction verification content (STVC) is encrypted by the seller private key and the buyer private key respectively as an undeniable basis. A vendor-side computer program product for use in a peer-to-peer electronic trading system. When the computer device loads and executes the computer program product, the steps as recited in claim 9 can be completed.