A homomorphic signcryption-based smart grid data encryption transmission method and system

Abstract

The application discloses a kind of smart grid data encryption transmission method and system based on homomorphic sign cipher, belongs to smart grid data transmission technical field, including power operation center generates public parameter and sends to user;User generates private key based on the public parameter, and the public parameter and the private key are used to the power data to be transmitted in user to sign and cipher, generate user report and send to gateway;Gateway uses the homomorphism of sign and cipher to aggregate the user report, obtain aggregated report, and send aggregated report to power operation center;Power operation center is decrypted to power data by aggregated report, and completes smart grid data encryption transmission;The application uses sign and cipher scheme, and the encryption and signature of data are completed by one calculation, effectively solve the problem of low encryption and decryption efficiency and large communication overhead in traditional method by superimposing encryption and signature steps to realize privacy and authentication.

Description

Technical Field

[0001] This invention relates to a method and system for encrypted data transmission in smart grids based on homomorphic signature cryptography, belonging to the field of smart grid data transmission technology. Background Technology

[0002] The smart grid is considered the next-generation approach to providing electricity to millions of homes. Its concept originated from the 2003 U.S. blackout, where communication delays in the control system prevented it from providing accurate information to grid workers in a timely manner. With advancements in information and communication technologies, developing a smarter grid infrastructure has become a viable option. Currently, the smart grid is one of the most promising solutions for next-generation grid systems. It utilizes information and communication technologies to collect and process information in an automated manner. Compared to the centralized, unidirectional transmission of traditional grids, the smart grid combines traditional grids with information and control technologies. It allows for decentralized, bidirectional transmission and emphasizes reliability and efficiency-driven response, aiming to provide stronger reliability, including self-healing, self-activation, and automatic outage management. It also pursues higher efficiency, including generation, transmission, and distribution. In terms of sustainability, the smart grid is committed to accommodating future renewable energy sources and improving network security.

[0003] Smart grids integrate computing and communication technologies into traditional power grids, making them intelligent and interconnected. Embedding processing and storage units in traditional meters, and communicating with household appliances and power generation and management facilities, provides excellent connectivity for smart grids. Through intelligent, networked smart meters, smart grids can monitor power transmission and consumption information in real time, subscribe to power usage, operate remotely, manage advanced demand and outages, and manage usage.

[0004] Because smart grids can monitor the electricity information of all users within the grid, this places higher demands on grid information security. Once attackers obtain this information, they can track and understand users' habits or lifestyles, violating their personal privacy. Furthermore, attackers could potentially falsify large-scale electricity consumption data to attack the smart grid, such as by overloading power plants. Therefore, ensuring secure data transmission within the smart grid has become a crucial problem that needs to be solved.

[0005] Most of the proposed solutions are based on homomorphic encryption algorithms. Through the homomorphism of ciphertext, data can be aggregated without decryption, effectively preventing information from being leaked during gateway processing. However, the integrity and authenticity of the information need to be guaranteed by additional signing steps, which greatly increases the computational overhead and places high demands on the computing power of smart meter devices.

[0006] CN112202544A presents a smart grid data security aggregation method based on the Paillier homomorphic encryption algorithm. By introducing the Paillier homomorphic encryption algorithm to encrypt data in the power grid, it effectively protects the privacy of power grid users and ensures that cloud computing centers cannot access the specific content of user data. It utilizes key-related hash-based message authentication codes (HMACs) to encrypt plaintext data. The validity of the message authentication code is verified during decryption, thereby effectively preventing tampering.

[0007] CN113078993A presents a third-party privacy protection method for smart grids based on an improved homomorphic encryption algorithm. This method modifies the Paillier homomorphic encryption algorithm, using a modified public key to encrypt electricity data to protect user privacy. The encrypted data and the signed ciphertext are sent to the gateway. After verifying data integrity, the gateway merges the encrypted electricity data and sends it along with the merged signature to the control center. The control center verifies data integrity again and finally decrypts the data using the modified private key to obtain the plaintext user electricity data. This method improves upon the Paillier homomorphic encryption algorithm and can be used for privacy protection in smart grids, safeguarding the confidentiality of user electricity consumption data.

[0008] To ensure confidentiality and authentication during data transmission, the above methods typically employ a sequence of encryption followed by signing. However, this approach incurs high computational costs and is inefficient. Summary of the Invention

[0009] The purpose of this invention is to provide a smart grid data encryption transmission method and system based on homomorphic signature encryption, which solves the problems of low encryption and decryption efficiency and high communication overhead in the existing technology.

[0010] To achieve the above objectives, the present invention employs the following technical solution:

[0011] In a first aspect, the present invention provides a method for encrypted data transmission in a smart grid based on homomorphic signature cryptography, comprising:

[0012] The power operation center generates public parameters and sends them to users;

[0013] The user generates a private key based on the public parameters, and uses the public parameters and the private key to signify the power data to be transmitted in the user's data, and generates a user report to send to the gateway.

[0014] The gateway aggregates the user reports using the homomorphism of the signature encryption to obtain an aggregated report, and then sends the aggregated report to the power operation center.

[0015] The power operation center decrypts the aggregated report to obtain power data, thus completing the encrypted transmission of smart grid data.

[0016] In conjunction with the first aspect, further, there are multiple users, and the public parameters are shared among the users as public values.

[0017] In conjunction with the first aspect, the power operation center further generates public parameters, including:

[0018] Obtain preset security parameters;

[0019] Randomly select a set of private keys from the power operation center and calculate the corresponding public key;

[0020] Obtain the preset cryptographic hash function;

[0021] The set of security parameters, public key, and cryptographic hash function is used as the public parameters.

[0022] In conjunction with the first aspect, the corresponding public key is further calculated using the following formula:

[0023] pk r =(Y0,Y1,Y2)=(x0P,x1P,x2P)

[0024] Among them, pk r is the public key, Y0, Y1 and Y2 are the three elements of the public key, x0, x1 and x2 are the first, second and third elements of the private key, P is the generator of the group -, and - is a cyclic group of prime order q, where q represents the order of the group.

[0025] In conjunction with the first aspect, furthermore, the signature encryption of the power data to be transmitted from the user based on the public parameters and the private key is performed using the following formula:

[0026] C i =(c i,0 ,c i,1 ,c i,2 )

[0027] c i,0 =t i P,c i,1 =m i P+t i Y0,c i,2 =w i Y0+sk RA m i Y1+t i Y2

[0028] Among them, C i This is the i-th user report, c i,0 c i,1 and c i,2These are the first, second, and third elements in the user report, t i It is the first random number, t i ∈Z q Z q It is an additive group modulo q, m i It's electricity data, w i It's the private key. It is a multiplicative group modulo q, sk RA It is a public-private key.

[0029] In conjunction with the first aspect, the gateway further aggregates the user reports using the homomorphism of the signature encryption to obtain an aggregated report, which is calculated using the following formula:

[0030] C = (c0, c1, c2)

[0031]

[0032]

[0033]

[0034] Where C is the aggregate report, and c0 is the aggregate report composed of c i,0 The elements derived from aggregation, c1 is the result of aggregation in the report. i,1 The aggregated element, c2, is from the aggregation report. i,2 The aggregated elements, where n is the number of electricity data.

[0035] In conjunction with the first aspect, furthermore, after completing the encrypted transmission of smart grid data, the process also includes a step where the power operation center verifies the power data, including:

[0036] The electricity data obtained from decryption is substituted into the following formula for verification:

[0037] c2=x0h+x1m′pk RA +x2c0

[0038] If the equation is true, the verification is successful and the power data has not been tampered with during transmission; if the equation is false, the verification fails and the power data has been tampered with during transmission.

[0039] Where m′ is the electricity data obtained from decryption, and c2 is the data obtained from the aggregation report by c i,2 Elements formed by aggregation, c i,2 It is the third element in the user report; c0 is the aggregated report containing c i,0 Elements formed by aggregation, c i,0The first element in the user report is x0, x1, and x2, which are the first, second, and third elements in the private key, respectively. h is the user's public key, and pk is the user's public key. RA It is the shared public key for the residential area.

[0040] In conjunction with the first aspect, furthermore, after verifying the power data, if the power data has been tampered with during transmission, the process also includes steps for the power operation center to trace the report's origin, including:

[0041] Send the verification failure message to the corresponding gateway;

[0042] When the gateway receives a verification failure message, it sends the user report to the power operation center one by one;

[0043] The power operation center verifies each user report, identifies tampered reports, and uses the private key of the tampered report to find the user who sent the report, thus tracing the report's origin.

[0044] In a second aspect, the present invention also provides a smart grid data encryption transmission system based on homomorphic signature encryption based on the method described in any one of the first aspects, including a user, a gateway, and a power operation center, wherein the gateway is communicatively connected to the user and the power operation center respectively;

[0045] The user is used to generate a private key based on the public parameters, to sign the power data to be transmitted in the user based on the public parameters and the private key, and to generate a user report to send to the gateway.

[0046] The gateway is used to aggregate the user reports using the homomorphism of the signature to obtain an aggregated report, and then send the aggregated report to the power operation center.

[0047] The power operation center is used to generate public parameters and send them to users, and also to decrypt aggregated reports to obtain power data, thus completing the encrypted transmission of smart grid data.

[0048] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0049] This invention provides a method and system for encrypted data transmission in smart grids based on homomorphic signature cryptography. Utilizing a signature cryptography scheme, data encryption and signing are completed in a single computation, effectively solving the problems of low encryption / decryption efficiency and high communication overhead inherent in traditional methods that rely on stacking encryption and signing steps to achieve confidentiality and authentication. Furthermore, this signature cryptography scheme is homomorphic, enabling the aggregation of regional data during data transmission while simultaneously decrypting. This avoids the computational waste and ciphertext leakage that often occur in smart grid scenarios where data aggregation requires decryption before transmission.

[0050] In summary, the beneficial effects can be summarized as follows:

[0051] First, this invention can prevent intentional tampering and forgery. The signature technology of this invention rigorously verifies the system's messages, ensuring that attackers cannot impersonate a legitimate smart meter device to intentionally tamper with or forge data.

[0052] Second, the encryption method of the present invention is based on homomorphic signature encryption technology, which can perform calculations without decryption during the power report aggregation process of the gateway, thereby avoiding data leakage that may occur when the gateway performs calculations and ensuring the security of the system.

[0053] Third, this invention has lower performance requirements for smart meter devices. Compared to the original method of encrypting first and then signing, the homomorphic signature encryption technology of this invention completes encryption and signing in a single calculation process, reducing the performance requirements of the device and also reducing communication overhead during transmission. Attached Figure Description

[0054] Figure 1 This is one of the flowcharts of a smart grid data encryption transmission method based on homomorphic signature encryption provided in an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of a smart grid data encryption transmission system based on homomorphic signature encryption provided in an embodiment of the present invention;

[0056] Figure 3 This is a smart grid network topology diagram provided in an embodiment of the present invention;

[0057] Figure 4 This is the second flowchart of a smart grid data encryption transmission method based on homomorphic signature encryption provided in an embodiment of the present invention;

[0058] Figure 5 This is a flowchart of the report tracing process provided in an embodiment of the present invention. Detailed Implementation

[0059] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0060] Example 1

[0061] like Figure 1 and Figure 4 As shown, this invention provides a smart grid data encryption transmission method based on homomorphic signature cryptography, comprising the following steps:

[0062] S1. The power operation center generates public parameters and sends them to users.

[0063] For the single-authority smart grid system considered in this embodiment (such as...) Figure 2 As shown in the figure, it is reasonable to assume that the power operations center (OA) can guide the entire system.

[0064] Step S1 specifically includes:

[0065] S1-1, Obtain preset security parameters.

[0066] The power operation center first generates the safety parameters (q, P, -), where P is the generator of the group - and - is a cyclic group of prime order q, where q represents the order of the group.

[0067] S1-2. Randomly select a set of private keys from the power operation center and calculate the corresponding public key.

[0068] The power operation center randomly selects a set of private keys. Let the coordinates be integers modulo q in three dimensions. Then, the corresponding public key is calculated using the following formula:

[0069] pk r =(Y0,Y1,Y2)=(x0P,x1P,x2P)

[0070] Among them, pk r Y0, Y1, and Y2 are the three elements of the public key, and x0, x1, and x2 are the first, second, and third elements of the private key, respectively.

[0071] S1-3. Obtain the preset encryption hash function.

[0072] The power operation center selects a secure cryptographic hash function.

[0073] S1-4. Use the set of security parameters, public key, and cryptographic hash function as common parameters.

[0074] After obtaining the public parameters, the power operation center publishes them. The expression for the public parameters is: pubs={q,P,-,pk} r ,H}.

[0075] S2. The user generates a private key based on the public parameters, and uses the public parameters and the private key to signify the power data to be transmitted in the user's system, generating a user report and sending it to the gateway.

[0076] S2-1. When the local gateway in a residential area registers itself with the system, it first selects a random number. Use it as the private key, and calculate the corresponding public key Y. g =xg P.

[0077] S2-2. For a residential area with n users, OA generates their public and private keys for the residential area, sk. RA =H(ID1||ID2||...||ID) i ||sk r ), where ID i Let pk be the identity ID corresponding to user i, and pk be the public key corresponding to the user. RA =sk RA P, is a public-private key shared by all users in the residential area.

[0078] S2-3, User ID in the residential area i Select random number Use it as the private key, and calculate the corresponding public key h. i =w i P, w i This represents the user's private key.

[0079] S2-4. Randomly select a random number t. i ∈Z q .

[0080] S2-5, Regarding power data m i Generate user report C i =(c i,0 ,c i,1 ,c i,2 ),in:

[0081] c i,0 =t i P,c i,1 =m i P+t i Y0,c i,2 =w i Y0+sk RA m i Y1+t i Y2

[0082] Among them, C i This is the i-th user report, c i,0 c i,1 and c i,2 These are the first, second, and third elements in the user report, t i It is the first random number, t i ∈Z q Z q It is an additive group modulo q, m i It's electricity data, w i It's the private key. It is a multiplicative group modulo q, sk RA It is a public-private key.

[0083] S2-6. The user (smart meter) sends the user report to the designated gateway GW.

[0084] S3. The gateway aggregates the user reports using the homomorphism of the signature encryption to obtain an aggregated report, and sends the aggregated report to the power operation center.

[0085] S3-1, The gateway processes the received reports.

[0086] S3-1-1, Gateway GW receives power data reports from users.

[0087] S3-1-2, in the report c i,0 Aggregate into

[0088] S3-1-3, in the report c i,1 Aggregate into

[0089] S3-1-4, in the report c i,2 Aggregate into

[0090] S3-1-5. Send the aggregated power report to the Power Operations Center (OA).

[0091] S3-2, Homomorphism of aggregated signatures

[0092] S3-2-1. Take the above aggregated report. and Then C = (c0, c1, c2) = (tP, mP + tY0, wY0 + sk) RA mY1+tY2), which is consistent with the original user electricity report format, is homomorphic.

[0093] Where C is the aggregate report, and c0 is the aggregate report composed of c i,0 The elements derived from aggregation, c1 is the result of aggregation in the report. i,1 The aggregated element, c2, is from the aggregation report. i,2 The aggregated elements, where n is the number of electricity data.

[0094] S4. The power operation center decrypts the aggregated report to obtain power data and completes the encrypted transmission of smart grid data.

[0095] S4-1, Report sent by the Power Operations Center OA Decryption Gateway

[0096] S4-1-1. The plaintext information can be calculated using the OA's private key and c0 and c1 from the report. Since Y0 = x0P, then m′P = c1 - x0c0. Because m′ is the electricity data over a period of time, the data volume is relatively small, and the OA can directly exhaustively solve for it.

[0097] S4-2, The OA uses the decrypted m′ to verify the report sent by the gateway.

[0098] S4-2-1. To ensure that the power reports are not tampered with during transmission and aggregation, the OA needs to further verify the power reports.

[0099] S4-2-2. Verify using the decrypted m′ and c0, c2, c2 = x0h + x1m′pk RA +x2c0; If the above formula is true, the verification passes. If the above formula is false, the verification fails, and it is possible that an attacker has tampered with the electricity report.

[0100] After verifying the power data, if the power data has been tampered with during transmission, the process also includes a step (S5) for the power operation center to trace the report back to its source. Figure 5 As shown, it includes:

[0101] Send the verification failure message to the corresponding gateway;

[0102] When the gateway receives a verification failure message, it sends the user report to the power operation center one by one;

[0103] The power operation center verifies each user report (following steps S4) to identify tampered reports and uses the private key of the tampered report to find the user who sent the report, thus tracing the report's origin.

[0104] In this embodiment, the signature encryption uses a homomorphic signature encryption algorithm, an improvement on the Elgamal encryption algorithm. It combines encryption with signature properties, ensuring the integrity and verifiability of the ciphertext. Furthermore, its homomorphic nature allows computation without decryption, facilitating aggregation by the gateway (GW). To improve efficiency, it can be implemented based on elliptic curve cryptography. Elliptic curve cryptography relies on the elliptic curve discrete logarithm problem, using points on the elliptic curve for encryption and decryption. Since solving the discrete logarithm problem on an elliptic curve is more complex, attackers require significantly more computational resources to crack it. Therefore, it can achieve the same security with a much shorter key than RSA, reducing system bandwidth and storage requirements.

[0105] This invention utilizes a data transmission method based on homomorphic signature encryption to ensure the security of power data during transmission. The gateway does not need to decrypt during the aggregation process, thus avoiding data leakage. At the same time, it leverages the low computational overhead of homomorphic signature encryption to reduce the performance requirements of smart meters and significantly reduce the deployment cost of smart grids.

[0106] Example 2

[0107] like Figure 2 As shown in the figure, this embodiment of the invention also provides a smart grid data encryption transmission system based on homomorphic signature encryption, including users, gateways, and a power operation center. The gateway is communicatively connected to both the users and the power operation center. The network topology diagram is shown below. Figure 3 As shown;

[0108] The user is used to generate a private key based on public parameters, and to sign the power data to be transmitted in the user's data based on the public parameters and the private key, and to generate a user report to send to the gateway.

[0109] The gateway is used to aggregate the user reports using the homomorphism of the signature to obtain an aggregated report, and then send the aggregated report to the power operation center.

[0110] The power operation center is used to generate public parameters and send them to users. It is also used to decrypt aggregated reports to obtain power data and complete the encrypted transmission of smart grid data.

[0111] Users (RA Residential Area): This includes local gateways connected to the smart grid operations center, and a large number of smart meters {sm1,sm2,...,sm} used by residential users. n}

[0112] Gateway (GW Gateway): This is a powerful workshop that primarily performs aggregation and relay functions. The aggregation component is responsible for aggregating residential user electricity consumption data into compressed data, while the relay component helps residential users forward data to the Operations Authority (OA) center. It also helps the OA center relay feedback to the RA (Regulatory Authority) users.

[0113] The OA Operation Authority (OA) is a trusted center responsible for guiding the entire system, receiving and processing users' electricity consumption data.

[0114] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for encrypted data transmission in a smart grid based on homomorphic signature cryptography, characterized in that, include: The power operation center generates public parameters and sends them to users; The user generates a private key based on the public parameters, and uses the public parameters and the private key to signify the power data to be transmitted in the user's data, and generates a user report to send to the gateway. The gateway aggregates the user reports using the homomorphism of the signature encryption to obtain an aggregated report, and then sends the aggregated report to the power operation center. The power operation center decrypts the aggregated report to obtain power data, thus completing the encrypted transmission of smart grid data. The process of signing and cryptographically transcribing the power data to be transmitted from the user based on the public parameters and the private key is performed using the following formula: ； ； in, It is the first Individual user reports, , and These are the first, second, and third elements in the user report. It is the first random number. , It is a model q addition group, It's electricity data. It's the private key. , It is a model q multiplication group It is a public-private key. , and These are the three elements in the public key. It is a generator of group G, where G is a prime number of order 1. q cyclic group q Indicates the order of the group; The gateway aggregates the user reports using the homomorphism of the signature, obtaining an aggregated report, which is calculated using the following formula: ； ； ； ； in, It's an aggregated report. It is a report from the aggregation team Elements that are aggregated It is a report from the aggregation team Elements that are aggregated It is a report from the aggregation team Elements that are aggregated It refers to the quantity of electricity data.

2. The smart grid data encryption transmission method based on homomorphic signature encryption according to claim 1, characterized in that, There are multiple users, and the public parameters are shared among the users as public values.

3. The smart grid data encryption transmission method based on homomorphic signature encryption according to claim 1, characterized in that, The power operation center generates common parameters, including: Obtain preset security parameters; Randomly select a set of private keys from the power operation center and calculate the corresponding public key; Obtain the preset cryptographic hash function; The set of security parameters, public key, and cryptographic hash function is used as the public parameters.

4. The smart grid data encryption transmission method based on homomorphic signature encryption according to claim 3, characterized in that, The corresponding public key is calculated using the following formula: ； in, It is a public key. , and These are the first, second, and third elements of the private key, respectively.

5. The smart grid data encryption transmission method based on homomorphic signature encryption according to claim 1, characterized in that, After the smart grid data encryption transmission is completed, the process also includes a step where the power operation center verifies the power data, including: The electricity data obtained from decryption is substituted into the following formula for verification: ； If the equation is true, the verification is successful and the power data has not been tampered with during transmission; if the equation is false, the verification fails and the power data has been tampered with during transmission. in, It is electricity data obtained by decryption. It is a report from the aggregation team Elements that are aggregated It is the third element in the user report. It is a report from the aggregation team Elements that are aggregated It is the first element in the user report. , and These are the first, second, and third elements of the private key, respectively. It is the user's public key. It is the shared public key for the residential area.

6. The smart grid data encryption transmission method based on homomorphic signature encryption according to claim 5, characterized in that, After verifying the power data, if the power data has been tampered with during transmission, the process also includes a step for the power operation center to trace the report back to its source, including: Send the verification failure message to the corresponding gateway; When the gateway receives a verification failure message, it sends the user report to the power operation center one by one; The power operation center verifies each user report, identifies tampered reports, and uses the private key of the tampered report to find the user who sent the report, thus tracing the report's origin.

7. A smart grid data encryption transmission system based on homomorphic signature encryption, according to any one of claims 1 to 6, characterized in that, This includes users, gateways, and the power operation center; the gateway communicates with both users and the power operation center. The user is used to generate a private key based on the public parameters, to sign the power data to be transmitted in the user based on the public parameters and the private key, and to generate a user report to send to the gateway. The gateway is used to aggregate the user reports using the homomorphism of the signature to obtain an aggregated report, and then send the aggregated report to the power operation center. The power operation center is used to generate public parameters and send them to users, and also to decrypt aggregated reports to obtain power data, thus completing the encrypted transmission of smart grid data.

Images