WO2021113295A1

WO2021113295A1 - System and method for transferring asset in a blockchain network

Info

Publication number: WO2021113295A1
Application number: PCT/US2020/062799
Authority: WO
Inventors: Ching Song Wu; Chih-Sheng Wang
Original assignee: Eland Blockchain Fintech Inc.
Priority date: 2019-12-05
Filing date: 2020-12-02
Publication date: 2021-06-10

Abstract

The invention discloses a system and method for transferring an asset in a blockchain network, wherein a smart contract is created in advance, and the smart contract has been signed in advance with a private key of the first account from which the asset is to be transferred out so that the smart contract fulfills the requirements for execution. The smart contract is securely preserved by an intermediate processing node. No matter if an account holder of the first account loses the private key of the first account, is dead, or in a state of incapacity, as long as the verification of the asset transfer is approved, the intermediate processing node will deploy the stored smart contract in the blockchain network for automatic execution, so that the asset is transferred from the first account to the second account.

Description

SYSTEM AND METHOD FOR TRANSFERRING ASSET IN A BLOCKCHAIN NETWORK

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a system and method for transferring an asset in a blockchain network, in particular to a method for dealing with the case where an account holder has lost a private key of his account and the problems associated with inheritance transfer in a blockchain network.

2. Description of the Related Art

[0002] In existing blockchain network technology, the most troublesome issue about the management of virtual assets is to deal with the problems of the loss of the account holder's private key and the inheritance transfer after the account holder's death.

[0003] At present, a variety of methods have been suggested for handling the issue on the loss of an account holder's private key. The most common one is to back up multiple private keys for self-keeping or to be kept by a third-party specific institution. When the account holder loses the private key, he may use a backup private key or retrieve the backup private key from the specific institution. This method is convenient, but there is a risk that the backup private key may be lost, or the third-party specific institution may have frauds in process. Besides, whether or not the specific institution would run for a long period of time is also a critical issue.

[0004] In addition, existing art, for example Taiwan Patent Publication No. TW201931815A, discloses a method of encrypting a private key and storing it in a blockchain. The method as disclosed in Taiwan Patent Publication No. TW201931815A first encrypts the private key (first private key) with the account holder’s biometric data to become the second private key, and then encrypts the second private key with the password set by the account holder to become the third private key. The third private key is then stored in the blockchain. In case the private key is lost, the third private key may be downloaded from the blockchain and decrypted step by step to retrieve the lost private key (first private key).

[0005] Although the method as disclosed in this prior art patent can preserve the backup private key in security, the original private key cannot be retrieved in case there are defects during the decrypting process of the private key, for example the account holder’s biometric data is destroyed or the set password is lose. In addition, this prior art patent still cannot solve the problem of inheritance transfer after the account holder’s death.

SUMMARY OF THE INVENTION

[0006] The primary object of the present invention is to provide a system and method for transferring an asset in a blockchain network, by means of which the asset may be retrieved in cases when the account holder loses the private key, and the asset may be transferred to the inheritor in cases where the account holder is dead or of incapacity.

[0007] To achieve the above objective, the present invention provides a system for transferring an asset in a blockchain network, the blockchain network including a first account node corresponding to a first account, a second account node corresponding to a second account, and an intermediate processing node. The intermediate processing node includes a processor and a memory module for storing at least one application program including a plurality of processor-executable instructions that, when executed, enables the processer to perform a process comprising the steps of: creating at least one smart contract and signing the at least one smart contract with a private key of the first account; and verifying an asset transfer in response to an asset transfer request made by the first account or the second account; after verification of the asset transfer is approved, the processor deploys the at least one smart contract in the blockchain network; and after the at least one smart contract is executed by any one of nodes in the blockchain network, an execution result associated with asset transfer from the first account to the second account is written into a new block.

[0008] Accordingly, according to the present invention, at least one smart contract is created in advance, and the smart contract has been signed in advance with a private key of the first account from which the asset is to be transferred out so that the smart contract fulfills the requirements for execution. The smart contract is securely preserved by an intermediate processing node. In case the first account loses the private key, as long as the verification of the asset transfer is approved (that is, for example the identity of the first account is verified), the intermediate processing node will deploy the stored smart contract in the blockchain network for automatic execution, so that the asset is transferred from the first account (source account) to the second account (backup account). [0009] On the other hand, in case that the account holder of the first account is dead or is of incapacity, that is physically, mentally or legally unable, after the verification of the asset transfer is approved by, for example, the joint signature of multiple predetermined accounts (including, for example, an inheritor account, witness accounts of relatives and/or lawyers, and the account of the intermediate processing node) so that the smart contract fulfills the requirements for execution. Likewise, the intermediate processing node deploys the smart contract in the blockchain network for automatic execution, so that the asset is transferred from the first account (source account) to the second account (inheritor account).

[0010] Therefore, the problems that an asset cannot be retrieved when the account holder's private key is lost and that inheritance cannot be transferred to an inheritor when the account holder is dead or of incapacity can be solved. Moreover, the method and system provided by the present invention are simple, reliable, and applicable to various blockchain networks.

[0011] To achieve the foregoing objective, the present invention provides a method for transferring an asset in a blockchain network having a first account node corresponding to a first account, a second account node corresponding to a second account, and an intermediate processing node. The method comprises the steps of: creating, by the intermediate processing node, at least one smart contract, and signing the at least one smart contract with a private key of the first account; and verifying, by the intermediate processing node, asset transfer in response to an asset transfer request made by the first account or the second account; and after verification of the asset transfer is approved, deploying, by the intermediate processing node, the at least one smart contract in the blockchain network. After executing the at least one smart contract by any one of nodes in the blockchain network, writing an execution result associated with the asset transfer from the first account to the second account into a new block.

[0012] To achieve the above objective, the present invention provides a system for transferring an asset in a blockchain network having a first account node corresponding to a first account, a second account node corresponding to a second account, and an intermediate processing node, the intermediate processing node comprising: a processor; and a memory module configured to store at least one application program including a plurality of processor-executable instructions that, when executed by the processor, enables the processer to perform a process comprising: creating a first smart contract and a second smart contract and signing the first smart contract and the second smart contract with a private key of the first account; encrypting the first smart contract with biometric data of an account holder of the first account and then storing the first smart contract and the second smart contract in the memory module; verifying asset transfer in response to an asset transfer request made by the first account or the second account; after verification of the asset transfer is approved, deploying the first smart contract and the second smart contract in the blockchain network. The verification of the asset transfer associated with the first smart contract is executed by verifying an identity of the account holder of the first account, while the verification of the asset transfer associated with the second smart contract is executed by verifying physiological condition information of the account holder of the first account.

[0013] Accordingly, the system or method according to the present invention, two smart contracts, namely the first and second smart contracts, can be created at the same time in advance. The first smart contract is created for dealing with retrieval of the asset in cases where the account holder of the first account loses the private key. The second smart contract is created for dealing with inheritance transfer in cases where the account holder of the first account is dead or of incapacity. Prior to executing the first smart contract, the identity of the account holder of the first account, for example biometric data such as the account holder's fingerprint, iris, voiceprint, ear profile or body fluid composition, a static password which may be a password generated by the account holder, or an one-time password (OTP) has to be verified. In other words, the identity of the account holder can be verified by using biometric authentication, static password authentication, one-time password (OTP) authentication or combination thereof. The first smart contract may be executed only after the identity of the account is confirmed.

[0014] Prior to executing the second smart contract, physiological condition information of the account holder of the first account, for example a death certificate of the account holder, a doctor’s diagnosis certificate, or disability certificate, etc. has to be provided and verified. The second smart contract may be executed only after the physiological condition of the account holder of the first account is confirmed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 schematically shows an architecture of a system for transferring an asset according to a preferred embodiment of the present invention;

FIG. 2 schematically shows an interaction scenario of an asset transfer preparation phase, wherein a method for transferring an asset according to a preferred embodiment of the present invention is implemented;

FIG. 3 schematically shows an interaction scenario of an asset transfer phase, wherein a method for transferring an asset according to a preferred embodiment of the present invention is implemented when an account holder loses his private key; and

FIG. 4 schematically shows an interaction scenario of an asset transfer phase, wherein a method for transferring an asset according to a preferred embodiment of the present invention is implemented in the course of inheritance transfer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention is related to a system and method for transferring an asset in a blockchain network. In the description, similar elements will be denoted by the same reference numerals. In addition, the drawings of the present invention are only intended to be illustrative, and are not necessarily drawn to scale, and all details are not necessarily be shown in the drawings.

[0017] Generally, the following embodiments are based on the fundamental architecture of existing blockchain network technology, and thus they can be implemented with no modification being made to the existing blockchain network architectures. The present invention can be directly applied on existing blockchain networks for the intended asset transfer.

[0018] Reference is made to FIG. 1 which schematically shows an architecture of a system for transferring an asset according to a preferred embodiment of the present invention. As shown in the figure, in a blockchain network BC such as Stellar Lumens, a first account node Upl, a second account node Up2, a plurality of witness account nodes Ual, Ua2, Ua3, and an intermediate processing node Gp are included. The first account node Upl corresponds to a first account, which is a source account from which the asset is to be transferred out. The second account node Up2 is a destination account to which the asset is to be transferred and which may be a backup account associated with the first account or an inheritor account in connection with the asset associated with the first account. [0019] The witness account nodes Ual, Ua2, Ua3 correspond to accounts of witnesses to inheritance transfer. Typically, the witnesses are lawyers, relatives of the account holder of the first account, or other impartial third parties. The intermediate processing node Gp represents a data processing and management center, which may be a data center where personnel are deployed for processing data. In addition, the intermediate processing node Gp includes a network interface I, a processor Pc, and a memory module M. The network interface I is used for connecting the intermediate processing node Gp to the blockchain network BC, and is responsible for receiving and sending information. An application program P is stored in the memory module M where the first smart contract Scl and the second smart contract Sc2 can also be stored.

[0020] Reference is made to FIG. 1 and FIG. 2 which schematically shows an interaction scenario of an asset transfer preparation phase, wherein a method for transferring an asset according to a preferred embodiment of the present invention is implemented. The present invention allows an account holder in the blockchain network BC to make preparation to solve the problem that his asset cannot be retrieved when the account holder lost his private key or that inheritance transfer cannot be executed in case of accidents upon the account holder. In step SI 00, the first account node Upl (the source account from which the asset is to be transferred out) submits a request to the intermediate processing node Gp to create a smart contract. In the present embodiment, in order to simultaneously solve the two problems associated with loss of the private key and inheritance transfer as mentioned above, two smart contracts have to be created at the same time. At this time, the account holder of the first account (the first account node Upl) must provide a backup account public key, an inheritor account public key and a witness account public key. The backup account may already exist or be newly created at that time.

[0021] Next, in step SI 05, after receiving the request and relevant data sent by the first account node Upl, the intermediate processing node Gp creates a first smart contract Scl and a second smart contract Sc2. The first smart contract Scl is provided for dealing with the problem of loss of the private key and includes information asset transfer from the first account to the second account. The second smart contract Sc2 is provided for dealing with inheritance transfer and includes information about inheritance transfer from the first account to the second account. However, the second smart contract is required to be signed with a plurality private keys. The second smart contract Sc2 can be executed only after the second smart contract Sc2 has been signed with respective private keys of the inheritor account (second account), the witness account, and the intermediate processing node Gp.

[0022] In step SI 10, the intermediate processing node Gp submits a request to the first account node Upl for signing the first and second smart contracts with the private key of the first account. Next, in step SI 15, the account holder (the first account node Upl) signs the first and second smart contracts Scl, Sc2 with his private key. It is to be noted that after the account holder signs with the private key, the first smart contract Scl basically has fulfilled the requirements for execution, and it can be directly executed once it is deployed in the blockchain network.

[0023] Next, the signed smart contracts are encrypted. In step S120, the intermediate processing node Gp makes a request for biometric data to the first account node Upl. In step S125, the account holder provides the intermediate processing node Gp with the biometric data, which may be the account holder’s fingerprint image, iris image, or facial image (for facial recognition). It should be particularly noted that, alternatively, the smart contract can also be encrypted by other methods, for example a static password generated by the account holder.

[0024] After the intermediate processing node Gp receives the account holder’s biometric data, in step SI 30, the first smart contract Scl is encrypted with the biometric data as specifically described below. The image associated with the account holder’s fingerprint, iris or facial profile is hashed with a hash function to generate a 128-bit or 256-bit character string composed of alphabetic characters and Arabic numerals. The character string as generated is used to encrypt the first smart contract Scl.

[0025] In this embodiment, to ensure the security of the contracts, the intermediate processing node Gp also encrypts the first and second smart contracts, as in step SI 35. The existing encryption method such as Advanced Encryption Standard (AES) may be used. Finally, in step SI 40, the encrypted first and second smart contracts are stored in the memory module M.

[0026] Reference is made to FIG. 1 and FIG. 3 which schematically shows an interaction scenario of an asset transfer phase, wherein a method for transferring an asset according to a preferred embodiment of the present invention is implemented when the account holder's private key is lost. The following will explain how to transfer the asset from the source account (first account) to the backup account (second account) in case the account holder loses the private key of the source account. Firstly, in step S200, the first account node makes a request to the intermediate processing node Gp. Then, the intermediate processing node Gp decrypts the account holder’s first smart contract Scl based on the request, as in step S205. In this step, the intermediate processing node Gp is required to perform decryption by itself since the encryption is carried out by the intermediate processing node Gp autonomously, see the step S135 In Fig. 2.

[0027] Next, verification of the asset transfer is started at step S210. In this step, the intermediate processing node Gp makes a request to the account holder, the first account node Upl, for biometric data. In step S215, in response to the request, the account holder (the first account node Upl) provides the same biometric data as that created originally.

[0028] Next, in step S220, the intermediate processing node Gp decrypts the first smart contract Scl with the received biometric data. Now, the decrypted first smart contract Scl basically fulfills all of the requirements for execution. Finally, in step S225, the first smart contract Scl is deployed in the blockchain network BC through the intermediate processing node Gp. In step S230, any one of nodes in the blockchain network BC may execute the first smart contract Scl, and an execution result (transaction) of asset transfer of the first account to the second account, is written into a new block. As such, a process for retrieving the asset from the account of which the private key is lost is accomplished.

[0029] It should be particularly noted that in this embodiment, the account holder shall provide at the beginning the public key of the backup account (second account) which already exists or is newly created at that time. Alternatively, in some other embodiments, creation of the backup account (second account) and provision of the public key of the backup account (second account) may be done after the intermediate processing node Gp has decrypted the first smart contract Scl with the biometric data in step S220. It can be avoided that the private key of the source account (first account) and the private key of the backup account (second account) would be lost simultaneously.

[0030] According to an aspect of this invention in which the first smart contract Scl is not encrypted by the account holder’s biometric data, any information or documents capable of proving the identity of the account holder of the first account, for example a one-time password (OTP) or other features, may be used to verify the asset transfer. [0031] Reference is made to FIG. 1 and FIG. 4 which schematically shows an interaction scenario of an asset transfer phase, wherein a method for transferring an asset according to a preferred embodiment of the present invention is implemented in the course of inheritance transfer. As will be further explained below, the present invention is applicable to the situation where the account holder is unable to transfer his asset due to accidents or other factors causing, disability, or loss of consciousness or the situation where an inherited asset cannot be transferred due to death of the account holder.

[0032] Firstly, in step S300, the second account node (the inheritor account node) Up2 makes a request to the intermediate processing node Gp. Then, in step S305, the intermediate processing node Gp decrypts the stored second smart contract Sc2 in response to the request. In this step, the intermediate processing node Gp only needs to perform decryption by itself since the encryption is carried out by the intermediate processing node Gp autonomously, see the step S135 In Fig. 2. In this embodiment, the second account node (the inheritor account node) Up2 makes an asset transfer request to the intermediate processing node Gp, but the present invention shall not be limited to this. Such a request may be made by other parties.

[0033] Then, the verification of the asset transfer is executed. For the verification, the second account node Up2 and the witness account nodes Ual, Ua2, Ua3 are required to sign the second smart contract Sc2 with their respective private keys. In step S310, the intermediate processing node Gp makes a request to the second account node Up2 for signing the second smart contract. In step S315, the second account node Up2 signs the second smart contract Sc2 with its private key. In step S320, the intermediate processing node Gp makes requests to the witness account nodes Ual, Ua2, Ua3 for signing the smart contract, respectively. In step S325, the witness account nodes Ual, Ua2, Ua3 sign the second smart contract Sc2 with their respective private keys.

[0034] It is to be noted that the witness account nodes Ual, Ua2, Ua3 may represent lawyers, relatives, friends, or other third-party notaries or agencies associated with the account holder of the first account. In this embodiment, although all of the witness account nodes Ual, Ua2, Ua3 are required to sign the second smart contract Sc2 with their respective private keys, a majority rule may be adopted in other aspects of the present invention. For example, if there are three witnesses, the second smart contract being signed by two of the witnesses with their respective private key would be sufficient. Alternatively, the second smart contract being signed by a single one of the witnesses with his private key would be sufficient. In other words, if necessary, it may be not required to sign the second smart contract by all of the witnesses with their respective private key. As such, the situation that the second smart contract cannot become ready to be executed once it is not signed by all of the witnesses due to loss of contact of one or more of the witnesses or other reasons can be avoided.

[0035] Next, in step S330, the intermediate processing node Gp signs the second smart contract Sc2 with its private key, thus fulfills all of the requirements for execution of the second smart contract Sc2. Finally, in step S335, the second smart contract Sc2 is deployed in the blockchain network BC through the intermediate processing node Gp. In step S340, any one of nodes in the blockchain network BC may execute the second smart contract Sc2, and an execution result (transaction) of the asset transfer from the first account to the second account, is written into a new block. As such, a process of inheritance transfer is accomplished.

[0036] The present invention further provides a method of verification of asset transfer executed by checking the physiological condition information of the account holder of the first account. In other words, steps S310 to S325 as shown in FIG. 4 can be replaced with the following steps: providing the intermediate processing node Gp with the death certificate information or doctor’s diagnosis certificate associated with the account holder of the first account issued by a third-party trusted institution (for example a hospital) by the second account node (the inheritor account node) Up2; signing the second smart contract Sc2 with its private key (step S330) by the intermediate processing node Gp and deploying it in the blockchain network BC for execution (steps S335, S340) after verification of the physiological condition information is approved by the intermediate processing node Gp.

[0037] On the other hand, the method of verification of asset transfer as described above may be as follows: a third-party trusted institution (such as a hospital) directly transmits the physiological condition information of the account holder of the first account to the intermediate processing node Gp which then verifies the physiological condition information of the account holder of the first account; the intermediate processing node Gp signs the second smart contract Sc2 with its private key and the private key of the third-party trusted institution; the signed smart contract is then deployed in the blockchain network BC for execution. [0038] The preferred embodiments of the present invention are illustrative only, and the invention is not limited to the details disclosed in the specification and the drawings. Accordingly, it is intended that the invention be not limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.

Claims

What is claimed is:

1. A system for transferring an asset in a blockchain network having a first account node corresponding to a first account, a second account node corresponding to a second account, and an intermediate processing node, the intermediate processing node comprising: a processor; and a memory module configured to store at least one application program; wherein the at least one application program includes a plurality of processor-executable instructions that, when executed by the processor, enables the processer to perform a process comprising: creating at least one smart contract and signing the at least one smart contract with a private key of the first account; and verifying asset transfer in response to an asset transfer request made by the first account or the second account and deploying the at least one smart contract in the blockchain network after verification of the asset transfer is approved; wherein, after the at least one smart contract is executed by any one of nodes in the blockchain network, an execution result associated with the asset transfer from the first account to the second account is written into a new block.

2. The system of claim 1, wherein an identity of an account holder of the first account is verified by using at least one of biometric authentication, static password authentication and one-time password (OTP) authentication for the verification of the asset transfer.

3. The system of claim 2, wherein after the at least one smart contract is signed with the private key of the first account, the processor encrypts the at least one smart contract with at least one of biometric data and a static password and stores the at least one smart contract in the memory module.

4. The system of claim 1, wherein after the at least one smart contract is signed with the private key of the first account, the processor encrypts the at least one smart contract and stores the at least one smart contract in the memory module.

5. The system of claim 1, wherein before the processor creates the at least one smart contract, the processor creates the second account and writes a public key of the second account into the at least one smart contract.

6. The system of claim 1, the processor writes a public key of the second account into the at least one smart contract after the verification of the asset transfer is approved, and deploys the at least one smart contract to the blockchain network.

7. The system of claim 1, wherein the verification of the asset transfer is executed by signing the at least one smart contract with respective private keys of a plurality of predetermined accounts other than the first account.

8. The system of claim 7, wherein the plurality of predetermined accounts comprise an intermediate processing account corresponding to the intermediate processing node, the second account, and at least one witness account.

9. The system of claim 1, wherein the processor creates a first smart contract and a second smart contract and signs each of the first smart contract and the second smart contract with the private key of the first account, the verification of the asset transfer associated with the first smart contract is executed by verifying an identity of an account holder of the first account; the verification of the asset transfer associated with the second smart contract is executed by verifying private key signatures of a plurality of predetermined accounts other than the first account.

10. A method for transferring an asset in a blockchain network having a first account node corresponding to a first account, a second account node corresponding to a second account, and an intermediate processing node, the method comprising: a step (A) of creating, by the intermediate processing node, at least one smart contract, and signing the at least one smart contract with a private key of the first account; and a step (B) of verifying, by the intermediate processing node, asset transfer in response to an asset transfer request made by the first account or the second account; and after verification of the asset transfer is approved, deploying, by the intermediate processing node, the at least one smart contract in the blockchain network; wherein, after executing the at least one smart contract by any one of nodes in the blockchain network, an execution result associated with the asset transfer from the first account to the second account is written into a new block.

11. The method of claim 10, wherein in the step (A), after signing the at least one smart contract with the private key of the first account, the at least one smart contract is encrypted by the intermediate processing node with at least one of biometric data and a static password of the first account.

12. The method of claim 10, wherein in the step (A), the intermediate processing node creates the second account before creating the at least one smart contract, and writes a public key of the second account into the at least one smart contract.

13. The method of claim 10, wherein in the step (B), an identity of an account holder of the first account is verified by using at least one of biometric authentication, static password authentication and one-time password (OTP) authentication for the verification of the asset transfer.

14. The method of claim 10, wherein in the step (B), the verification of the asset transfer is executed by signing the at least one smart contract with respective private keys of a plurality of predetermined accounts other than the first account.

15. The method of claim 10, wherein in the step (A), the intermediate processing node creates a first smart contract and a second smart contract and signs the first smart contract and the second smart contract with the private key of the first account; and in the step (B), the verification of the asset transfer associated with the first smart contract is executed by verifying an identity of an account holder of the first account; and the verification of the asset transfer associated with the second smart contract is executed by verifying private key signatures of a plurality of predetermined holder accounts other than the first account.

16. A system for transferring an asset in a blockchain network having a first account node corresponding to a first account, a second account node corresponding to a second account, and an intermediate processing node, the intermediate processing node comprising: a processor; and a memory module configured to store at least one application program; wherein the at least one application program includes a plurality of processor-executable instructions that, when executed by the processor, enables the processer to perform a process comprising the steps of: creating a first smart contract and a second smart contract and signing the first smart contract and the second smart contract with a private key of the first account; encrypting the first smart contract and the second smart contract and then storing the encrypted first and second smart contracts in the memory module; and verifying asset transfer in response to an asset transfer request made by the first account or the second account and deploying the first second smart contract and the second smart contract in the blockchain network after verification of the asset transfer is approved; wherein the verification of the asset transfer associated with the first smart contract is executed by verifying an identity of an account holder of the first account; the verification of the asset transfer associated with the second smart contract is executed by assessing physiological condition of the account holder of the first account; wherein, after the first smart contract or the second smart contract is executed by any one of nodes in the blockchain network, an execution result associated with the asset transfer from the first account to the second account is written into a new block.

17. The system of claim 16, wherein, after the processor encrypts the first contract with biometric data of the account holder of the first account, the processor encrypts the first smart contract and the second smart contract and stores the smart contracts in the memory module.