阅读说明：本技术 基于区块链的车位管理系统及方法 (Parking space management system and method based on block chain ) 是由 韩晖 于 2021-09-22 设计创作，主要内容包括：本发明实施例涉及计算机数据处理技术领域,公开了一种基于区块链的车位管理系统,该系统包括：目标节点、目标车位设备以及客户端；客户端,用于发送车位授权请求至区块链；目标节点,用于接收车位授权请求,根据智能合约对车位授权请求进行验证；当车位授权请求验证通过时,根据车位授权请求和节点公钥生成授权指令,并对授权指令进行广播；客户端,还用于获取授权指令,根据待验证客户端密钥和授权指令生成授权数据包,将授权数据包发送至目标车位设备；目标车位设备,用于接收授权数据包,对授权数据包进行验证；当授权数据包验证通过时,执行授权动作。通过上述方式,本发明实施例提高了车位管理的安全性。(The embodiment of the invention relates to the technical field of computer data processing, and discloses a parking space management system based on a block chain, which comprises: the system comprises a target node, target parking space equipment and a client; the client is used for sending a parking space authorization request to the block chain; the target node is used for receiving the parking space authorization request and verifying the parking space authorization request according to an intelligent contract; when the parking space authorization request passes the verification, generating an authorization instruction according to the parking space authorization request and the node public key, and broadcasting the authorization instruction; the client is also used for acquiring an authorization instruction, generating an authorization data packet according to the client key to be verified and the authorization instruction, and sending the authorization data packet to the target parking space equipment; the target parking space equipment is used for receiving the authorization data packet and verifying the authorization data packet; and when the authorization data packet passes the verification, executing an authorization action. Through the mode, the embodiment of the invention improves the safety of parking space management.)

1. A parking space management system based on a block chain is characterized by comprising a target node, target parking space equipment and a client; the target node is one of a plurality of selectable nodes in a block chain; the selectable node stores an intelligent contract and a node public key corresponding to the selectable node; the target parking space equipment is one of a plurality of optional parking space equipment; wherein the content of the first and second substances,

the client is used for sending a parking space authorization request to the block chain;

the target node is used for receiving the parking space authorization request and verifying the parking space authorization request according to the intelligent contract;

the target node is further used for generating an authorization instruction according to the parking space authorization request and the node public key when the parking space authorization request passes verification, and broadcasting the authorization instruction;

the client is further used for acquiring the authorization instruction, generating an authorization data packet according to a client key to be verified and the authorization instruction, and sending the authorization data packet to target parking space equipment;

the target parking space equipment is used for receiving the authorization data packet and verifying the authorization data packet;

and the target parking space equipment is also used for executing an authorization action when the authorization data packet passes verification.

2. The system according to claim 1, wherein a first parking space equipment identifier corresponding to each optional parking space equipment and at least one legal client public key associated with each first parking space equipment identifier are stored in the intelligent contract; the parking space authorization request comprises a second parking space equipment identifier and a public key of a client to be authorized; the target node includes:

the first matching unit is used for respectively matching the second parking space equipment identifier with each first parking space equipment identifier and determining the matched first parking space equipment identifier as a parking space equipment identifier to be authorized;

the first matching unit is further configured to match each legal client public key associated with the parking space device identifier to be authorized with the client public key to be authorized;

and when the legal client public key is matched with the client public key to be authorized, the first verification unit is used for determining that the parking space authorization request passes verification and determining the legal client public key matched with the client public key to be authorized as a target client public key.

3. The system of claim 2, wherein the intelligent contract further comprises an available time corresponding to each of the legitimate client public keys; the parking space authorization request also comprises the use time;

the first matching unit is further used for matching the use time with the available time;

when the using time is matched with the available time, the first verification unit is further used for determining that the parking space authorization request is verified.

4. The system of claim 2, wherein the target node further comprises:

the sequence unit is used for determining request sequence information corresponding to the parking space authorization request when the parking space authorization request passes verification;

the first generation unit is used for generating information to be signed according to the request time sequence information, the node public key, the parking space equipment identifier to be authorized and the target client public key;

the signature unit is used for signing the information to be signed according to the node public key to obtain a node signature;

the first generating unit is further configured to generate the authorization instruction according to the node signature and the information to be signed.

5. The system according to claim 4, wherein the client key to be verified comprises a client private key to be verified and a client public key to be verified; the client comprises:

the encryption unit is used for encrypting the authorization instruction according to the private key of the client to be verified to obtain an encrypted instruction;

and the second generation unit is used for generating the authorization data packet according to the encrypted instruction and the public key of the client to be verified.

6. The system of claim 5, wherein the target parking space device comprises:

the analysis unit is used for analyzing the authorization data packet to obtain the public key of the client to be verified and the instruction to be decrypted;

the decryption unit is used for decrypting the instruction to be decrypted according to the public key of the client to be verified, and when the instruction to be decrypted is decrypted successfully, the instruction to be verified is obtained;

the inquiry unit is used for inquiring the public key of the client to be verified in the instruction to be verified;

and when the public key of the client to be verified is inquired, the second verification unit is used for determining that the authorization data packet passes verification.

7. The system of claim 6, wherein the target parking space device further comprises: the storage unit is used for storing all the node public keys;

the analysis unit is also used for analyzing the instruction to be verified to obtain a signature to be verified;

the query unit is further configured to query the node public keys in the to-be-verified instruction respectively;

when the node public key is inquired, the decryption unit is further used for decrypting the signature to be verified according to the inquired node public key;

and when the signature to be verified is successfully decrypted, the second verification unit is also used for determining that the authorization data packet passes verification.

8. The system according to claim 7, wherein the intelligent contract further comprises legal usage time and legal device type corresponding to each legal client public key; the parking space authorization request also comprises time to be authorized and the type of equipment to be authorized;

the first matching unit is also used for matching the time to be authorized with the legal use time corresponding to the target client public key;

when the time to be authorized is matched with the legal use time, the first verification unit is further used for determining that the parking space authorization request is verified;

the first generating unit is also used for writing the time to be authorized and the type of the equipment to be authorized into the information to be signed.

9. The system of claim 8, wherein the storage unit is further configured to store a target device type of the target parking space device;

the analysis unit is also used for analyzing the instruction to be verified to obtain the time to be authorized and the type of the equipment to be authorized;

the target parking space equipment further comprises a second matching unit, and the second matching unit is further used for matching the type of the equipment to be authorized with the type of the target equipment;

when the type of the device to be authorized is successfully matched with the type of the target device, the second verification unit is further used for determining that the authorization data packet is verified;

the target parking space equipment further comprises a charging unit, wherein the charging unit is used for starting timing after the authorization action is executed, executing an authority recovery action and stopping timing when an authorization ending request is received, so that the actual use time is obtained;

the charging unit is also used for determining target charge information according to the actual use time;

the charging unit is further configured to display the target cost information.

10. A block chain-based parking space management method, which is applied to the block chain-based parking space management system according to any one of claims 1 to 7; the method comprises the following steps:

sending a parking space authorization request to the block chain through the client;

receiving the parking space authorization request through the target node, and verifying the parking space authorization request according to the intelligent contract;

when the parking space authorization request passes the verification, generating an authorization instruction by the target node according to the parking space authorization request and the node public key, and broadcasting the authorization instruction;

obtaining the authorization instruction through the client, generating an authorization data packet according to a client key to be verified and the authorization instruction, and sending the authorization data packet to target parking space equipment;

receiving the authorization data packet through the target parking space equipment, and verifying the authorization data packet;

and when the authorization data packet passes the verification, executing an authorization action through the target parking space equipment.

Technical Field

The embodiment of the invention relates to the technical field of computer data processing, in particular to a parking space management system and method based on a block chain.

Background

At present, with the annual increase of automobile keeping volume, safe and effective management of parking spaces is a common goal of users and parking space providers. The parking stall management is generally carried out through the parking stall lock in the existing market, and current parking stall lock generally includes mechanical parking stall lock, remote control parking stall lock and intelligent parking stall lock.

The inventor finds out in the process of implementing the invention that: the current intelligent parking spot lock mainly adopts a third party operation management mode, namely, a user needs to be connected with a third party platform service through a mobile phone to obtain authorization information, so that the parking spot is used or rented. The authorization information of the parking spot lock is usually completely controlled by a third-party platform, so that the problem of low safety exists in the existing parking spot management.

Disclosure of Invention

In view of the above problems, embodiments of the present invention provide a parking space management system and method based on a block chain, which are used to solve the problem of low security of parking space management in the prior art.

According to an aspect of an embodiment of the present invention, a parking space management system based on a block chain is provided, where the system includes a target node, a target parking space device, and a client; the target node is one of a plurality of selectable nodes in a block chain; the selectable node stores an intelligent contract and a node public key corresponding to the selectable node; the target parking space equipment is one of a plurality of optional parking space equipment; wherein the content of the first and second substances,

the client is used for sending a parking space authorization request to the block chain;

the target node is used for receiving the parking space authorization request and verifying the parking space authorization request according to the intelligent contract;

the target node is further used for generating an authorization instruction according to the parking space authorization request and the node public key when the parking space authorization request passes verification, and broadcasting the authorization instruction;

the client is further used for acquiring the authorization instruction, generating an authorization data packet according to a client key to be verified and the authorization instruction, and sending the authorization data packet to target parking space equipment;

the target parking space equipment is used for receiving the authorization data packet and verifying the authorization data packet;

and the target parking space equipment is also used for executing an authorization action when the authorization data packet passes verification.

In an optional mode, a first parking space equipment identifier corresponding to each optional parking space equipment and at least one legal client public key associated with each first parking space equipment identifier are stored in the intelligent contract; the parking space authorization request comprises a second parking space equipment identifier and a public key of a client to be authorized; the target node includes:

the first matching unit is used for respectively matching the second parking space equipment identifier with each first parking space equipment identifier and determining the matched first parking space equipment identifier as a parking space equipment identifier to be authorized;

the first matching unit is further configured to match each legal client public key associated with the parking space device identifier to be authorized with the client public key to be authorized;

and when the legal client public key is matched with the client public key to be authorized, the first verification unit is used for determining that the parking space authorization request passes verification and determining the legal client public key matched with the client public key to be authorized as a target client public key.

In an optional manner, the intelligent contract further includes available time corresponding to each legal client public key; the parking space authorization request also comprises the use time;

the first matching unit is further used for matching the use time with the available time;

when the using time is matched with the available time, the first verification unit is further used for determining that the parking space authorization request is verified.

In an optional manner, the target node further includes:

the sequence unit is used for determining request sequence information corresponding to the parking space authorization request when the parking space authorization request passes verification;

the first generation unit is used for generating information to be signed according to the request time sequence information, the node public key, the parking space equipment identifier to be authorized and the target client public key;

the signature unit is used for signing the information to be signed according to the node public key to obtain a node signature;

the first generating unit is further configured to generate the authorization instruction according to the node signature and the information to be signed.

In an optional mode, the to-be-verified client key comprises a to-be-verified client private key and a to-be-verified client public key; the client comprises:

the encryption unit is used for encrypting the authorization instruction according to the private key of the client to be verified to obtain an encrypted instruction;

and the second generation unit is used for generating the authorization data packet according to the encrypted instruction and the public key of the client to be verified.

In an optional mode, the target parking space device includes:

the analysis unit is used for analyzing the authorization data packet to obtain the public key of the client to be verified and the instruction to be decrypted;

the decryption unit is used for decrypting the instruction to be decrypted according to the public key of the client to be verified, and when the instruction to be decrypted is decrypted successfully, the instruction to be verified is obtained;

the inquiry unit is used for inquiring the public key of the client to be verified in the instruction to be verified;

and when the public key of the client to be verified is inquired, the second verification unit is used for determining that the authorization data packet passes verification.

In an optional mode, the target parking space device further includes: the storage unit is used for storing all the node public keys;

the analysis unit is also used for analyzing the instruction to be verified to obtain a signature to be verified;

the query unit is further configured to query the node public keys in the to-be-verified instruction respectively;

when the node public key is inquired, the decryption unit is further used for decrypting the signature to be verified according to the inquired node public key;

and when the signature to be verified is successfully decrypted, the second verification unit is also used for determining that the authorization data packet passes verification.

In an optional mode, the parsing unit is further configured to parse the to-be-verified instruction to obtain time sequence information to be verified;

the storage unit is also used for storing historical time sequence information; the historical time sequence information is the time sequence information to be verified included in an authorization data packet which is passed by the latest verification of the target parking space equipment;

the target parking space equipment further comprises:

the second matching unit is used for comparing the time sequence information to be verified with the historical request time sequence information;

and when the comparison of the time sequence information to be verified is successful, the second verification unit is further used for determining that the authorization data packet passes verification.

In an optional manner, the intelligent contract further includes legal use time and legal device type corresponding to each legal client public key; the parking space authorization request also comprises time to be authorized and the type of equipment to be authorized;

the first matching unit is also used for matching the time to be authorized with the legal use time corresponding to the target client public key;

when the time to be authorized is matched with the legal use time, the first verification unit is further used for determining that the parking space authorization request is verified;

the first generating unit is also used for writing the time to be authorized and the type of the equipment to be authorized into the information to be signed.

In an optional manner, the storage unit is further configured to store a target device type of the target parking space device;

the analysis unit is also used for analyzing the instruction to be verified to obtain the time to be authorized and the type of the equipment to be authorized;

the second matching unit is further configured to match the type of the device to be authorized with the type of the target device;

when the type of the device to be authorized is successfully matched with the type of the target device, the second verification unit is further used for determining that the authorization data packet is verified;

the target parking space equipment further comprises a charging unit, wherein the charging unit is used for starting timing after the authorization action is executed, executing an authority recovery action and stopping timing when an authorization ending request is received, so that the actual use time is obtained;

the charging unit is also used for determining target charge information according to the actual use time;

the charging unit is further configured to display the target cost information.

According to an aspect of an embodiment of the present invention, a block chain-based parking space management method is provided, where the method is based on the aforementioned block chain-based parking space management system, and the method includes:

sending a parking space authorization request to the block chain through the client;

receiving the parking space authorization request through the target node, and verifying the parking space authorization request according to the intelligent contract;

when the parking space authorization request passes the verification, generating an authorization instruction by the target node according to the parking space authorization request and the node public key, and broadcasting the authorization instruction;

obtaining the authorization instruction through the client, generating an authorization data packet according to a client key to be verified and the authorization instruction, and sending the authorization data packet to target parking space equipment;

receiving the authorization data packet through the target parking space equipment, and verifying the authorization data packet;

and when the authorization data packet passes the verification, executing an authorization action through the target parking space equipment.

The method comprises the steps of firstly calling a preset intelligent contract through a target node in a block chain to verify a parking space authorization request sent by a client, generating an authorization instruction corresponding to the parking space authorization request according to a node public key and returning the authorization instruction to the client under the condition that the authorization is passed, carrying out encryption processing on the authorization instruction again by the client according to a key of the client to be verified to obtain an authorization data packet by the client, sending the authorization data packet to target parking space equipment, finally analyzing and verifying the authorization data packet by the target parking space equipment, and executing a preset authorization action when the authorization is passed.

The parking space management method and the parking space management system are different from the problem that parking space use in the prior art needs to be managed by means of a third-party platform, reliability and usability of the third-party platform are difficult to guarantee, and therefore safety of parking space management in the prior art are low.

The foregoing description is only an overview of the technical solutions of the embodiments of the present invention, and the embodiments of the present invention can be implemented according to the content of the description in order to make the technical means of the embodiments of the present invention more clearly understood, and the detailed description of the present invention is provided below in order to make the foregoing and other objects, features, and advantages of the embodiments of the present invention more clearly understandable.

Drawings

The drawings are only for purposes of illustrating embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 shows a schematic structural diagram of a parking space management system based on a block chain according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram illustrating a parking space management system based on a block chain according to another embodiment of the present invention;

fig. 3 shows a schematic flow chart of the parking space management method based on the block chain according to the embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein.

Before the description of the embodiments of the present invention, the following terms are explained:

blockchain (Blockchain): a novel application mode with the technical characteristics of a computer, such as distributed data storage, point-to-point transmission, node consensus, safe encryption and the like, utilizes a block chain type data structure to verify and store data, utilizes a distributed node consensus algorithm to produce and update data, utilizes cryptography to ensure the safety of data transmission and access, and adopts decentralized block chains, so that the novel application mode has the characteristics of openness and credibility.

Public chain (Public blockchain): namely, a public blockchain means that each node in the blockchain is public, anyone can participate in the calculation of the blockchain, and everyone can obtain complete blockchain data through downloading, which is also called a blockchain account book.

Federation chain (Consortium blockchain): a system between public chain and private chain is controlled by multiple authority nodes assigned by organization, and the nodes manage and operate the whole system together according to a common recognition mechanism. The federation chain can be considered as "partially decentralized", that is, the public can check the reading and the transaction, but the permission of the federation needs to be obtained for verifying the transaction or issuing an intelligent contract.

Smart contract (Smart contract): the digitalized version of the traditional contract is a programmed code in nature, is stored and operated in a blockchain in an open mode, can be automatically executed under the condition that the agreed conditions are met, the intelligent contract allows credible transaction without a third party, and the calling record of the intelligent contract can be tracked and can not be reversed.

Fig. 1 shows a block chain-based parking space management system according to an embodiment of the present invention.

As shown in fig. 1, the system includes the following parts: client 101, target node and target parking space equipment 103.

The client 101 is configured to send a parking space authorization request, where the parking space authorization request is used to authorize a use of a parking space, and the client 101 may include a computer processing device such as a mobile phone and a notebook computer. The target node is one of a plurality of selectable nodes in the blockchain 102 that constitute a blockchain system, and the blockchain type may include a federation chain, a public chain, and so on. Target parking space equipment 103 is one of a plurality of optional parking space equipment, and optional parking space equipment is used for carrying out right of use control to the parking stall, can include intelligent parking stall lock, garage entrance guard's equipment etc..

In an embodiment of the present invention, the client 101 is configured to send a parking space authorization request to the block chain.

In an embodiment of the present invention, the client 101 may connect to the blockchain 102 through a preset proxy gateway, and send the parking space authorization request to the blockchain 102 in a broadcast manner.

In an embodiment of the present invention, the parking space authorization request includes, for example, client identification information of the client, client key information, parking space device identification, request duration information, and the like. The client identification information and the client key information are used for specifically marking the client.

And the target node is used for receiving the parking space authorization request and verifying the parking space authorization request according to the intelligent contract.

In an embodiment of the invention, when the parking space authorization request is randomly sent to one of the optional nodes, the optional nodes verify the request content after receiving the parking space authorization request, determine the target node through a block chain consensus mechanism, run a code for requesting authorization approval of the parking space in the intelligent contract by the target node, respond to the authorization request, and broadcast the response message. The block chain consensus mechanism includes, but is not limited to, POW (Proof Of Work), PBFT (byzantine fault-tolerant algorithm), and the like.

In yet another embodiment of the present invention, a master node may be further disposed in the blockchain 102 as a management node, where the management node is configured to receive a parking space authorization request, select the parking space authorization request according to the computing capability of each selectable node, determine a target node from the selectable nodes, and forward the parking space authorization request to the target node, so as to improve efficiency of parking space management in high-concurrency scenes such as a parking peak period or when the number of selectable nodes is small.

In one embodiment of the invention, the intelligent contract may be pre-deployed in a block chain network, and the intelligent contract includes a plurality of sub-contracts, and the content agreed by each sub-contract is different.

The intelligent contract at least comprises a first sub-contract and a second sub-contract, wherein the first sub-contract is used for completing initialization of parking space equipment, namely specific parking space equipment identification information corresponding to at least one parking space to be managed and legal client identification information associated with the parking space to be managed are written into each optional node of the block chain. The association with the parking space to be managed refers to the right to use the parking space to be managed, and the associated person may be an owner of the parking space to be managed, such as a developer, a parking space owner, or a shared person of the parking space to be managed, such as a carport person.

The second sub-contract is used for verifying the parking space authorization request, namely after the parking space authorization request is responded, matching the identity information of a legal client with the identity information of a client to be verified in the parking space authorization request, determining whether the parking space authorization request is legal or not, generating a corresponding authorization instruction when the parking space authorization request is legal, and broadcasting the node transaction record at the same time, wherein the intelligent contract can be regarded as one node transaction when the intelligent contract is called once.

In an embodiment of the present invention, a node public key corresponding to the optional node is stored in the optional node, and the node public key is used to specifically identify each optional node, and when each optional node performs a transaction or signature, the node public key can be added to a transaction record as its own identity authentication information, and the transaction record is stored in a block chain, so that a transaction process in the block chain can be traced.

In another embodiment of the present invention, the intelligent contract stores a first parking space device identifier corresponding to each optional parking space device and at least one legal client public key associated with each first parking space device identifier; the parking space authorization request comprises a second parking space equipment identifier and a public key of a client to be authorized.

The first parking space device identifier is used for specifically representing each optional parking space device, one optional parking space device corresponds to at least one optional parking space, and the first parking space device identifier may be a hardware identifier of the optional parking space device.

Referring to fig. 2, the target node includes: and a first matching unit 1021, configured to match the second parking space device identifier with each of the first parking space device identifiers, respectively, and determine the matched first parking space device identifier as a parking space device identifier to be authorized.

For example, the target node stores first parking space device identifiers L1, L2, and L3 corresponding to parking spaces to be managed P1, P2, and P3, respectively, and if the second parking space device identifier may be L2, the parking space device identifier to be authorized is L2.

The first matching unit 1021 is further configured to match each legal client public key associated with the parking space device identifier to be authorized with the client public key to be authorized, respectively.

In an embodiment of the present invention, the valid client public key associated with L2 may include K1, K2, and K3, which correspond to the parking owner, the first tenant, and the second tenant of P2, respectively, and the client public key to be authorized may be K3.

When the valid client public key is matched with the to-be-authorized client public key, the first verification unit 1022 is configured to determine that the parking space authorization request passes verification, and determine the valid client public key matched with the to-be-authorized client public key as a target client public key.

In an embodiment of the present invention, when the valid client public key is the same as the to-be-authorized client public key, it is determined that the valid client public key and the to-be-authorized client public key match. When the valid client public key does not match the client public key to be authorized, the first verification unit 1022 is configured to determine that the parking space authorization request verification fails.

And the target node is also used for generating an authorization instruction according to the parking space authorization request and the node public key and broadcasting the authorization instruction when the parking space authorization request passes verification.

In an embodiment of the invention, the node public key and the request parameter passing the verification in the parking space authorization request can be combined to obtain the authorization instruction. The request parameter may include the client identification information, the client key information, the parking space device identification, the request duration information, and the like of the client.

In another embodiment of the present invention, in order to further improve the security of the authorization instruction, the request parameter in the parking space authorization request and the parameter combination of the node public key may also be signed according to the node public key to obtain a node signature, and the node signature and the parameter combination are secondarily combined to obtain the authorization instruction.

Therefore, in a further embodiment of the present invention, referring to fig. 2, the target node further comprises:

and the sequencing unit 1023 is used for determining the request sequence information corresponding to the parking space authorization request when the parking space authorization request passes verification.

In an embodiment of the present invention, the request timing information includes transaction success time and transaction sequence number information in the block link point corresponding to the parking space authorization request. Wherein, the successful transaction refers to the successful execution of the second subcontract used for verifying the parking space authorization request.

And each optional node of the block chain stores historical transaction success times, and each optional node adds one to the historical transaction success times to obtain the transaction sequence number information when the second subcontract is executed once successfully, and stores the transaction sequence number information and the transaction records in the block chain.

For example, when the historical transaction success number is 100, a parking space authorization request sent by an account corresponding to the client public key K3 is received and verified, the transaction sequence number information corresponding to K3 is 101, and the historical transaction success number stored in the block chain is updated to 101.

And the first generating unit 1024 is configured to generate information to be signed according to the request timing sequence information, the node public key, the parking space device identifier to be authorized, and the target client public key.

In an embodiment of the invention, the request timing sequence information, the node public key, the parking space equipment identifier to be authorized and the target client public key are combined to obtain the information to be signed.

In a further embodiment of the present invention, the parameter combination in the information to be signed may be in the form of key-value pairs, such as: requesting timing information: 12. node public key: 123ABC, a parking space device identifier to be authorized: c001 and the target client public key: 456EFG, or string splicing, such as 12/123ABC/C001/456 EFG; each parameter item in the information to be signed is separated by a preset separator.

In still another embodiment of the present invention, a hash calculation may be performed according to the request timing sequence information, the node public key, the to-be-authorized parking space device identifier, and the target client public key to obtain a first hash value, and the first hash value is determined as the to-be-signed information.

And the signature unit 1025 is used for signing the information to be signed according to the node public key to obtain a node signature.

In one embodiment of the invention, the signature algorithm of the node public key can adopt a symmetric encryption algorithm or a digital signature algorithm. The first generating unit 1024 is further configured to generate the authorization instruction according to the node signature and the information to be signed.

In one embodiment of the present invention, the node signature may be combined with the information to be signed to obtain the authorization instruction. The specific combination mode may be character string splicing, or hash calculation according to the node signature and the information to be signed to obtain a second hash value, and the second hash value is determined as the authorization instruction.

The client 101 is further configured to obtain the authorization instruction, generate an authorization data packet according to the client key to be verified and the authorization instruction, and send the authorization data packet to the target parking space device 103.

Since the public chain, the alliance chain and other non-private chains have public property, anyone can acquire an authorization instruction from the block chain, and therefore there is a risk that a counterfeiter impersonates a client to be authorized and sends the acquired authorization instruction to the parking space equipment to acquire authorization.

Therefore, by adding the to-be-verified client key provided by the client 101 on the basis of the authorization instruction, and comparing the to-be-verified client key with the relevant information of the client passing the verification recorded in the authorization instruction, whether the client 101 is a counterfeiter can be judged.

Therefore, in an embodiment of the present invention, the to-be-verified client key includes a to-be-verified client private key and a to-be-verified client public key; the client 101 includes:

and the encryption unit 1011 is configured to encrypt the authorization instruction according to the to-be-verified client private key to obtain an encrypted instruction.

In an embodiment of the present invention, a preset symmetric encryption algorithm or an asymmetric encryption algorithm may be adopted to calculate the authorization instruction according to the private key of the client to be verified, so as to obtain an encrypted instruction.

A second generating unit 1012, configured to generate the authorization packet according to the encrypted instruction and the public key of the client to be verified.

In an embodiment of the invention, the encrypted instruction and the public key of the client to be verified are combined to obtain the authorization data packet. The combination mode may be hash calculation, character string splicing, or key value pair combination.

And the target parking space equipment 103 is used for receiving the authorization data packet and verifying the authorization data packet.

In an embodiment of the present invention, the target parking space device 103 has a communication module, and the communication module is used to implement bluetooth or network communication between the target parking space device 103 and the outside, such as the client 101, so as to receive the authorization data packet sent by the client 101.

In an embodiment of the present invention, the verification process of the target parking space device 103 on the authorization data packet may include two aspects, on one hand, whether a sender of the authorization data packet initiates a parking space authorization request in a block chain and has an authorization instruction to be verified, and on the other hand, whether the authorization instruction to be verified of the sender of the authorization data packet is valid is verified, wherein the authorization data packet may be analyzed to obtain a public key of a client to be verified and an instruction to be decrypted, then the instruction to be decrypted is decrypted according to the public key of the client to be verified, when the decryption is successful, the authorization data packet is proved to be valid and the instruction to be verified is obtained, and then the public key of the client to be verified and parameters included in the instruction to be verified are cross-verified, thereby completing the verification of whether the authorization instruction to be verified is valid.

Therefore, in an embodiment of the present invention, the target parking space device 103 includes:

and an analyzing unit 1031, configured to analyze the authorization packet to obtain the public key of the client to be verified and the instruction to be decrypted.

In an embodiment of the present invention, operations such as format conversion, hash calculation, and the like may be performed on the authorization data packet to obtain the public key of the client to be verified and the instruction to be decrypted.

And the decryption unit 1032 is configured to decrypt the instruction to be decrypted according to the public key of the client to be verified, and obtain the instruction to be verified when the instruction to be decrypted is decrypted successfully.

In one embodiment of the present invention, the decryption unit 1032 stores therein the encryption algorithm and the signature algorithm in the encryption unit 1011, the first generation unit 1024, and the generation unit 1025, which are described above.

In one embodiment of the invention, when the decryption of the instruction to be decrypted fails, the authorization data packet is determined to be not verified.

The query unit 1033 is configured to query the public key of the client to be verified in the instruction to be verified.

When the to-be-verified instruction includes the client public key to be verified, it indicates that the transaction initiation object corresponding to the to-be-verified instruction is consistent with the transmission object of the authorization data packet, and therefore, when the client public key to be verified is queried, the second verification unit 1034 is configured to determine that the authorization data packet is verified.

After the verification that whether the corresponding authorization instruction exists in the sending object of the authorization data packet is completed, in order to improve the safety of parking space management, the second verification can be further performed on whether the authorization instruction is verified and signed by the target node. Therefore, in another embodiment of the present invention, the target parking space device 103 further includes: a storage unit 1035 for storing all the node public keys.

The parsing unit 1031 is further configured to parse the to-be-verified instruction to obtain a to-be-verified signature.

In an embodiment of the present invention, the parsing manner of the instruction to be verified may include hash calculation, key-value pair reading, character string identification, and the like.

The query unit 1033 is further configured to query the node public keys in the to-be-verified instruction respectively.

In an embodiment of the present invention, when any node public key is not queried in the instruction to be verified, it is determined that the authorization packet verification fails.

When the node public key is queried, it indicates that the instruction to be verified is generated by the target node in the block chain when the transaction is successful, that is, the parking space authorization request is legal, and therefore, in a further embodiment of the present invention, the decryption unit 1032 is further configured to decrypt the signature to be verified according to the queried node public key.

When the decryption of the signature to be verified is successful, which indicates that the instruction to be verified is signed by the target node in the blockchain, the second verification unit 1034 is further configured to determine that the authorization packet is verified.

In one embodiment of the present invention, the second verification unit 1034 determines that the authorization packet is not verified when the decryption of the signature to be verified fails.

In another embodiment of the present invention, considering that not every authorization instruction is processed by the client 101, a corresponding authorization data packet is generated and sent to the target parking space device 103 for re-verification, i.e. whether the blockchain transaction is successfully authorized by the parking space device is not completely synchronized.

Therefore, there may be a case where the parking space authorization requests sequentially sent by the clients C1, C2, and C3 respectively pass the verification of the target node, and the time sequence of the clients C1, C2, and C3 sending the authorization data packets is C3, C1 (C2 is not sent).

In this scenario, the authorization of the target parking space device in the embodiment of the present invention is based on the time when the authorization data packet passes the verification, rather than the generation time of the authorization instruction in the authorization data packet in the block chain, so as to avoid the situation that multiple shared legal users exist in one parking space and the parking space authorization requests of the users conflict with each other, and further ensure the security of parking space management.

Therefore, in another embodiment of the present invention, the parsing unit 1031 is further configured to parse the to-be-verified instruction to obtain to-be-verified timing information.

With reference to the foregoing example, the number of successful historical transactions in the blockchain is 101, and the time sequence information to be verified corresponding to the clients C1, C2, and C3 are 102, 103, and 104, respectively.

The storage unit 1035 is further configured to store historical timing information; the historical time sequence information is the time sequence information to be verified included in the authorization data packet which is passed by the latest verification of the target parking space equipment 103.

With reference to the foregoing example, the number of successful historical transactions in the block chain is 101, and the historical timing information is 101, that is, all the clients that have succeeded in the historical transactions in the block chain send authorization data packets, and the target parking space device successfully completes the authorization action.

The target parking space device 103 further includes: a second matching unit 1036, configured to compare the to-be-verified timing sequence information with the history request timing sequence information.

When the comparison of the timing sequence information to be verified is successful, the second verification unit 1034 is further configured to determine that the authorization packet is verified.

In an embodiment of the present invention, when the timing information to be verified is greater than the history request timing information, it is determined that the comparison of the timing information to be verified is successful.

In consideration of the situation that multiple clients share one target parking space device, there are also scenes in which multiple clients share multiple target parking space devices, and at this time, the multiple target parking space devices need to be reasonably and correctly allocated to each client. Therefore, in another embodiment of the present invention, the intelligent contract further includes legal use time and legal device type corresponding to each legal client public key; the parking space authorization request also comprises time to be authorized and the type of equipment to be authorized.

The legal use time may include a legal use time period, such as 2 hours, and/or a legal use time interval, such as monday to friday, 9:00-18: 00. The legal device types refer to the parking space device types corresponding to the public keys of the legal clients, and different parking space device types correspond to different parking space types, such as electric vehicle parking spaces, motor vehicle parking spaces and the like.

The first matching unit 1021 is further configured to match the time to be authorized with the legal use time corresponding to the target client public key.

In one embodiment of the present invention, the time to be authorized may include a time period to be authorized for use, such as 30 minutes, and/or a time interval to be authorized for use, such as monday through friday, 10:00-17:00, and the like.

In one embodiment of the invention, the time length of the use to be authorized is matched with the time length of the legal use, and the time interval of the use to be authorized is matched with the time interval of the legal use.

When the time to be authorized matches the legal use time, the first verification unit 1022 is further configured to determine that the parking space authorization request is verified.

In an embodiment of the present invention, when the to-be-authorized use duration is less than the legal use duration, and when the to-be-authorized use time interval is located in the legal use time interval, it is determined that the to-be-authorized time is successfully matched with the legal use time corresponding to the target client public key.

The first generating unit 1024 is further configured to write the time to be authorized and the type of the device to be authorized into the information to be signed.

In an embodiment of the present invention, when the target node verifies the parking space authorization request, the target node verifies the use permission of the requester, that is, verifies the type of the parking space device that can be used by the client, the time length and the time interval that can be used, in addition to verifying the identity of the requester, that is, verifying the parking space device identifier and the client key information, thereby further improving the security of parking space management.

In yet another embodiment of the present invention, the storage unit 1035 is further configured to store a target device type of the target parking space device.

The parsing unit 1031 is further configured to parse the to-be-verified instruction to obtain the to-be-authorized time and the type of the to-be-authorized device.

The second matching unit 1036 is further configured to match the device type to be authorized with the target device type.

When the matching between the device type to be authorized and the target device type is successful, the second verification unit 1034 is further configured to determine that the authorization packet is verified.

In an embodiment of the invention, when the type of the device to be authorized is the same as the type of the target device, such as both the devices are electric vehicle parking space devices, it is determined that the two devices are successfully matched.

The target parking space device 103 is further configured to execute an authorization action when the authorization data packet is verified.

In an embodiment of the present invention, the authorization action refers to an action that enables the client 101 to use a parking space corresponding to the target parking space device, for example, when the target parking space device 103 is an intelligent parking space lock, the authorization action includes an unlocking action. The specific unlocking action can be unlocking by the intelligent parking space lock control motor driving device. When the target parking space device 103 is a garage access control device, the authorization action may be to display or send a door access control code to the client 101, and the like.

In yet another embodiment of the present invention, after determining that the authorization packet is verified, the storage unit 1035 further updates the history request timing information according to the timing information to be verified. The updating mode can be that the time sequence information to be verified is determined as historical request time sequence information, so that the synchronization degree of the request time sequence information in the parking space equipment and the transaction time sequence in the block chain is improved.

In yet another embodiment of the present invention, considering that in addition to performing the authorization action, the authorization usually has a certain validity period, such as a certain time period paid by the client, the target parking space device needs to charge the usage of the parking space and recover the authority, thereby completing the whole life cycle of the parking space management.

Therefore, in another embodiment of the present invention, the target parking space device further includes a charging unit 1037, where the charging unit 1037 is configured to start timing after the authorization action is performed, and execute the authority recovery action and stop timing when the authorization end request is received, so as to obtain the actual usage time.

The permission recovery action may be locking, access code invalidation, or the like. The authorization ending request can be sent by the client to the target parking space equipment or sent after a third subcontract in the block chain node is triggered, the third subcontract is used for responding to a use ending request sent by the client, the use ending request comprises the target client public key, the actual use time is compared with the time to be authorized corresponding to the target client public key, and when the actual use time is longer than the time to be authorized, the authorization ending request is sent to the target parking space equipment.

The charging unit 1037 is further configured to determine target cost information according to the actual usage time.

In an embodiment of the present invention, the target cost information is determined according to a preset unit time cost for the actual usage time, wherein the unit time cost may be determined according to a parking space device type of the target parking space device, a client level corresponding to the target client public key, and the like.

The charging unit 1037 is further configured to display the target cost information.

In an embodiment of the present invention, the displaying of the target fee information may be performed by a displaying module on the target parking space device, or the target fee information may be sent to the client 101 and the target node by the communication module.

In another embodiment of the present invention, the legal usage time and the account balance corresponding to the target client public key are updated according to the target fee information.

In another embodiment of the present invention, an authorization log corresponding to each valid client public key is further stored in the target node, where the authorization log includes authorization instruction generation time, target parking space device identifier, parking space device authorization time, and the like. The target node also writes the target expense information into an authorization log corresponding to the target client public key, so that the public credible storage of the authorization record is realized, and the account checking and auditing of subsequent parking space authorization transactions are facilitated.

The parking space management method and the parking space management system are different from the problem that parking space use in the prior art needs to be managed by means of a third-party platform, reliability and usability of the third-party platform are difficult to guarantee, and therefore safety of parking space management in the prior art are low.

Fig. 3 shows a schematic flow chart of the parking space management method based on the block chain according to the embodiment of the present invention. As shown in fig. 3, the method includes:

the method is applied to a parking space management system based on a block chain, and the system comprises a target node, target parking space equipment 103 and a client 101; the target node is one of a plurality of selectable nodes in a block chain; the selectable node stores an intelligent contract and a node public key corresponding to the selectable node; the target parking space device 103 is one of a plurality of optional parking space devices; the method comprises the following steps:

step 201: and sending a parking space authorization request to the block chain through the client 101.

In an embodiment of the present invention, the client 101 is configured to send a parking space authorization request to the block chain.

In an embodiment of the present invention, the client 101 may connect to the block chain through a preset proxy gateway, and send the parking space authorization request to the block chain in a broadcast manner.

In an embodiment of the present invention, the parking space authorization request includes, for example, client identification information of the client, client key information, parking space device identification, request duration information, and the like. The client identification information and the client key information are used for specifically marking the client.

Step 202: and receiving the parking space authorization request through the target node, and verifying the parking space authorization request according to the intelligent contract.

In an embodiment of the invention, when the parking space authorization request is broadcast and sent to each optional node, each optional node triggers a judgment code for judging whether the intelligent contract meets the response condition after receiving the parking space authorization request, the optional node meeting the response condition is a target node, and the target node responds to the parking space authorization request and broadcasts the response message. Wherein the response condition may include that the current number of outstanding transactions is less than a preset threshold value, and the like.

In another embodiment of the present invention, a master node may be further disposed in the block chain as a management node, where the management node is configured to receive the parking space authorization request, select the parking space authorization request according to the computing capability of each selectable node, determine a target node from the selectable nodes, and forward the parking space authorization request to the target node, so as to improve efficiency of parking space management in high concurrent scenes such as a parking peak period or in a situation where the number of selectable nodes is small.

In one embodiment of the invention, the intelligent contract may be pre-deployed in a block chain network, and the intelligent contract includes a plurality of sub-contracts, and the content agreed by each sub-contract is different.

The intelligent contract at least comprises a first sub-contract and a second sub-contract, wherein the first sub-contract is used for completing initialization of parking space equipment, namely specific parking space equipment identification information corresponding to at least one parking space to be managed and legal client identification information associated with the parking space to be managed are written into each optional node of the block chain. The association with the parking space to be managed refers to the right to use the parking space to be managed, and the associated person may be an owner of the parking space to be managed, such as a developer, a parking space owner, or a shared person of the parking space to be managed, such as a carport person.

The second sub-contract is used for verifying the parking space authorization request, namely after the parking space authorization request is responded, matching the identity information of a legal client with the identity information of a client to be verified in the parking space authorization request, determining whether the parking space authorization request is legal or not, generating a corresponding authorization instruction when the parking space authorization request is legal, and broadcasting the node transaction record at the same time, wherein the intelligent contract can be regarded as one node transaction when the intelligent contract is called once.

In an embodiment of the present invention, a node public key corresponding to the optional node is stored in the optional node, and the node public key is used to specifically identify each optional node, and when each optional node performs a transaction or signature, the node public key can be added to a transaction record as its own identity authentication information, and the transaction record is stored in a block chain, so that a transaction process in the block chain can be traced.

In another embodiment of the present invention, the intelligent contract stores a first parking space device identifier corresponding to each optional parking space device and at least one legal client public key associated with each first parking space device identifier; the parking space authorization request comprises a second parking space equipment identifier and a public key of a client to be authorized.

The first parking space device identifier is used for specifically representing each optional parking space device, one optional parking space device corresponds to at least one optional parking space, and the first parking space device identifier may be a hardware identifier of the optional parking space device.

Step 203: and when the parking space authorization request passes the verification, generating an authorization instruction by the target node according to the parking space authorization request and the node public key, and broadcasting the authorization instruction.

In an embodiment of the present invention, the second parking space equipment identifier is respectively matched with each of the first parking space equipment identifiers, and the matched first parking space equipment identifier is determined as a parking space equipment identifier to be authorized.

For example, the target node stores first parking space device identifiers L1, L2, and L3 corresponding to parking spaces to be managed P1, P2, and P3, respectively, and if the second parking space device identifier may be L2, the parking space device identifier to be authorized is L2.

And matching each legal client public key associated with the parking space equipment identifier to be authorized with the client public key to be authorized through a target node.

In an embodiment of the present invention, the valid client public key associated with L2 may include K1, K2, and K3, which correspond to the parking owner, the first tenant, and the second tenant of P2, respectively, and the client public key to be authorized may be K3.

And when the legal client public key is matched with the client public key to be authorized, determining that the parking space authorization request passes the verification through a target node, and determining the legal client public key matched with the client public key to be authorized as a target client public key.

In an embodiment of the present invention, when the valid client public key is the same as the to-be-authorized client public key, it is determined that the valid client public key and the to-be-authorized client public key match. And when the legal client public key does not match with the client public key to be authorized, determining that the parking space authorization request verification fails through the target node.

And when the parking space authorization request passes the verification, generating an authorization instruction by a target node according to the parking space authorization request and the node public key, and broadcasting the authorization instruction.

In an embodiment of the invention, the node public key and the request parameter passing the verification in the parking space authorization request can be combined to obtain the authorization instruction. The request parameter may include the client identification information, the client key information, the parking space device identification, the request duration information, and the like of the client.

In another embodiment of the present invention, in order to further improve the security of the authorization instruction, the request parameter in the parking space authorization request and the parameter combination of the node public key may also be signed according to the node public key to obtain a node signature, and the node signature and the parameter combination are secondarily combined to obtain the authorization instruction.

Step 204: the authorization instruction is obtained through the client 101, an authorization data packet is generated according to the key of the client 101 to be verified and the authorization instruction, and the authorization data packet is sent to the target parking space equipment 103.

In an embodiment of the present invention, since a public chain, a alliance chain, and other non-private chains have public property, anyone can acquire an authorization instruction from a block chain, and thus there is a risk that a counterfeiter impersonates a client to be authorized and sends the acquired authorization instruction to a parking space device to acquire authorization.

Therefore, by adding the to-be-verified client key provided by the client 101 on the basis of the authorization instruction, and comparing the to-be-verified client key with the relevant information of the client passing the verification recorded in the authorization instruction, whether the client 101 is a counterfeiter can be judged.

Therefore, in an embodiment of the present invention, the to-be-verified client key includes a to-be-verified client private key and a to-be-verified client public key; and encrypting the authorization instruction according to the private key of the client to be verified through the client 101 to obtain an encrypted instruction.

In an embodiment of the present invention, a preset symmetric encryption algorithm or an asymmetric encryption algorithm may be adopted to calculate the authorization instruction according to the private key of the client to be verified, so as to obtain an encrypted instruction.

And generating the authorization data packet by the client 101 according to the encrypted instruction and the public key of the client to be verified.

In an embodiment of the invention, the encrypted instruction and the public key of the client to be verified are combined to obtain the authorization data packet. The combination mode may be hash calculation, character string splicing, or key value pair combination.

Step 205: and receiving the authorization data packet through the target parking space equipment 103, and verifying the authorization data packet.

In an embodiment of the present invention, the verification process of the target parking space device 103 on the authorization data packet may include two aspects, on one hand, whether a sender of the authorization data packet initiates a parking space authorization request in a block chain and has an authorization instruction to be verified, and on the other hand, whether the authorization instruction to be verified of the sender of the authorization data packet is valid is verified, wherein the authorization data packet may be analyzed to obtain a public key of a client to be verified and an instruction to be decrypted, then the instruction to be decrypted is decrypted according to the public key of the client to be verified, when the decryption is successful, the authorization data packet is proved to be valid and the instruction to be verified is obtained, and then the public key of the client to be verified and parameters included in the instruction to be verified are cross-verified, thereby completing the verification of whether the authorization instruction to be verified is valid.

Thus, in one embodiment of the present invention, step 205 further comprises: and analyzing the authorization data packet through the target parking space equipment 103 to obtain the public key of the client to be verified and the instruction to be decrypted.

In an embodiment of the present invention, operations such as format conversion, hash calculation, and the like may be performed on the authorization data packet to obtain the public key of the client to be verified and the instruction to be decrypted.

And decrypting the instruction to be decrypted by the target parking space equipment 103 according to the public key of the client to be verified, and obtaining the instruction to be verified when the instruction to be decrypted is decrypted successfully.

In one embodiment of the invention, when the decryption of the instruction to be decrypted fails, the authorization data packet is determined to be not verified.

And inquiring the public key of the client to be verified in the instruction to be verified through the target parking space equipment 103.

When the to-be-verified instruction includes the client public key to be verified, it indicates that the transaction initiating object corresponding to the to-be-verified instruction is consistent with the sending object of the authorization data packet, and therefore, when the client public key to be verified is inquired, it is determined that the authorization data packet is verified through the target parking space equipment 103.

Step 206: and when the authorization data packet passes verification, executing an authorization action through the target parking space equipment 103.

In an embodiment of the present invention, the authorization action refers to an action that enables the client 101 to use a parking space corresponding to the target parking space device, for example, when the target parking space device 103 is an intelligent parking space lock, the authorization action includes an unlocking action. The specific unlocking action can be unlocking by the intelligent parking space lock control motor driving device. When the target parking space device 103 is a garage access control device, the authorization action may be to display or send a door access control code to the client 101, and the like.

The specific method steps of the block chain-based parking space management method provided by this embodiment are basically the same as the working process of the block chain-based parking space management system, and therefore are not described in detail again.

The parking space management method and the parking space management system are different from the problem that parking space use in the prior art needs to be managed by means of a third-party platform, reliability and usability of the third-party platform are difficult to guarantee, and therefore safety of parking space management in the prior art are low.

The algorithms or displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Various general purpose systems may also be used with the teachings herein. The required structure for constructing such a system will be apparent from the description above. In addition, embodiments of the present invention are not directed to any particular programming language. It is appreciated that a variety of programming languages may be used to implement the teachings of the present invention as described herein, and any descriptions of specific languages are provided above to disclose the best mode of the invention.

In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the embodiments of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the invention and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim.

Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names. The steps in the above embodiments should not be construed as limiting the order of execution unless specified otherwise.