CN107172043B - A kind of smart power grid user sale of electricity method based on homomorphic cryptography - Google Patents

Abstract

The present invention relates to smart grid electricity sales, and in particular to a method for smart grid user electricity sales based on homomorphic encryption. Send to each user, the user encrypts the power purchase demand data through homomorphic encryption, and then sends it to the community gateway, the community gateway sums the power purchase demand data of each user and sends it to the power company, and the power company receives it from the community gateway After uploading the power purchase demand data, decrypt and restore the data. The present invention uses hash function, bilinear pairing, and homomorphic encryption to cover up the user's real power purchase demand data, and authenticates the identity of the data sender, so that neither the community gateway nor the power company other than the user can obtain the data. The user's specific electricity purchase demand data effectively prevents the user's privacy from being disclosed and protects the fairness of market transactions.

Description

A method for selling electricity to smart grid users based on homomorphic encryption

technical field

The invention relates to smart grid electricity sales, in particular to a smart grid user electricity sales method based on homomorphic encryption.

Background technique

Smart grid, based on an integrated, high-speed two-way communication network, uses advanced sensing and measurement technology, advanced equipment technology, advanced control methods, and advanced decision support system technology to achieve reliable, safe, and economical power grids. , High efficiency, environmental friendliness and safe and efficient operation. With the increasing development of the smart grid, power companies no longer need staff to provide door-to-door service, but only realize various business transactions through network communication with the terminal. During this process, the security of information transmission is the focus of attention. The protection of privacy has also become a primary issue for power companies.

Encryption of transmitted information plays a certain role in guaranteeing information interaction between power companies and users. Homomorphic encryption is a relatively common and effective method among existing information encryption methods. The patent application number is 201410396335.X The document discloses a billing method with privacy protection in the smart grid. The smart meter records the power consumption of the user in real time, and uses the method of homomorphic encryption to encrypt the data and send it to the aggregator. The aggregator will receive a The power ciphertext used by the user for many times is decrypted through summation and then decrypted to obtain the plaintext of the user's accumulated power consumption. The aggregator then sends the plaintext of the power consumption to the billing department for calculation of electricity costs. The encryption method encrypts the data, but only realizes the encryption and decryption of the entire data transmission through the public-private key pair and the encryption algorithm, and cannot guarantee its security during the data transmission process.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a smart grid user electricity selling method based on homomorphic encryption. The process includes that the power company sends the electricity purchase request data to the community gateway, and the community gateway first verifies that the electricity purchase request data is correct After that, it is sent to each user, and the user encrypts the power purchase demand data through homomorphic encryption, and then sends it to the community gateway. The community gateway sums the power purchase demand data of each user and sends it to the power company, and the power company receives After the power purchase demand data uploaded by the community gateway, the data is decrypted and restored;

Specifically include the following steps:

(1) System initialization:

The power company should choose some parameters, including the cyclic group G with order q, _GT and a bilinear pair to all set up; calculate Generate a homomorphic encryption public key pair (f, g) and the corresponding private key λ, where a, b are elements in the is the prime number group whose order is q, P and P ₀ are the elements in the cyclic group G;

The four hash functions include H ₁ : {0, 1} ^* → G, H ₃ : G _T ×G _T → {0, 1} ^* , {0, 1} ^* represents a set composed of binary sequences of arbitrary bit length; according to the selected parameters, the power company, gateway and user obtain their own private key respectively and the public key;

(2) Power purchase request:

The power company sends power purchase request data to the community gateway, including the identity ID _u of the power company, the identity ID _g of the community gateway, price information Info _p , secret key r _u P ₀ , time stamp TS and signature σ _u ;

(3) Community gateway verification

When the community gateway receives the power purchase request data, it first verifies the authenticity and integrity of the data according to the timestamp TS and the signature _σu , and then sends it to each user in the community;

(4) User replies:

The user uses homomorphic encryption technology to cover up the real power purchase demand data to obtain Bi, and generates a digital signature σ _i and a message authentication code MAC(B _{i )} to reply to the community gateway;

(5) Community gateway aggregation:

The community gateway aggregates the received power purchase demand data of all users, obtains the aggregated signature σ, aggregates the power purchase demand data B, the secret key group {r _i P ₀ }, and the message authentication code MAC _f , and sends it to the power company;

(6) Decryption by the power company:

After the power company receives the aggregated power purchase demand data sent by the community gateway, it decrypts the data and restores the power sales share b ^(x) and verifies it.

Further, the community gateway communicates with the user in the smart meter communication network (AMI) based on a single-hop network topology (single-hop).

Furthermore, the communication between the power company and the community gateway is based on the 5G network.

Further, the private key and public key in step (1) are generated as follows:

(a) Electric company ID _u from Randomly select an element sk _u as the private key, and calculate PK _u = sk _u P ₀ as the public key;

(b) Community gateway ID _g from Randomly select an element sk _g as the private key, and calculate PK _g = sk _g P ₀ as the public key;

(c) User ID _i from Randomly select an element sk _i as the private key, and calculate PK _i = sk _i P ₀ as the public key;

(d) The power company releases public parameters Among them, U and V are randomly selected elements in the cyclic group G.

Further, the verification of the price information Info _p , the signature σ _u and the power purchase request data in step (2) and step (3) is carried out as follows:

(a) Price information Info _p ={p ₁ , p ₂ ,...,p _k }, where k is the total number of time slots, and p is the electricity sale price in any time slot;

(b) Signature σ _u ＝sk _u H ₁ (ID _u ||ID _g ||Info _p ||r _u P ₀ ||TS), the community gateway uses σ _u to verify the authenticity and integrity of the power purchase request data ;

(d) After the community gateway receives the power purchase request data, it first verifies the timestamp TS, and then verifies the equation Whether it is established.

Further, the process of masking the real power purchase demand data in step (4) is as follows:

(a) Calculate the secret key r _i is a random number, and r _g is a random number, and

(b) Using the homomorphic encryption algorithm to cover up the real power purchase demand data to obtain Then get the set B _i =(B _i,1 ,B _i,2 ,...,B _i,k ), where is a random number in the composite order group with order f ² , f is a prime number, b _{i, x} represent the real power purchase demand data;

(c) Generate message authentication code

(d) Generate a digital signature σ _i =sk _i H ₁ (H(k _i )||ID _g ||ID _u ||r _i P ₀ ||TS).

Further, the community gateway aggregation in step (5) is performed according to the following process:

(a) Under the smart meter communication network (AMI) of the single-hop network topology (single-hop), the aggregated signature σ=∑ _1≤i≤n σ _i , n represents the number of users in this method;

(b) aggregate power purchase demand data in each time slot in Then get the set B=(B ⁽¹⁾ , B ⁽²⁾ ,..., B ^(k) ), (1≤x≤k), r _g is a random number, and

(c) Message authentication code MAC(B)=Π _1≤i≤n MAC(B _i ), meanwhile, the community gateway randomly selects an element R to obtain message authentication code MAC _f =(MAC ₁ , MAC ₂ ), where MAC ₂ =U ^H(B) V ^{H (R)} , where,

Further, in step (6), the power company decrypts according to the following process:

(b) According to the homomorphic encryption algorithm, use the private key λ to restore the aggregated power purchase demand data of each time slot where L is function, x is the argument of the function;

(c) Verification Equation Whether it is established, and if it is established, the verification is passed;

(d) calculation And verification MAC ₂ ＝U ^H(B') V ^H(R') , B' is the aggregated power purchase demand data sent by the community gateway received by the power company,

A method for selling electricity to smart grid users based on homomorphic encryption of the present invention has the following beneficial effects:

According to the one-way and two-wire pair characteristics of the hash function, the non-repudiation and data integrity of the power company, community gateway, and user information are ensured by means of public key signature and private key verification; according to the characteristics of homomorphic encryption , which hides the real information of the user, thereby protecting the privacy of the sender and ensuring confidentiality; except for the user himself, neither the community gateway nor the power company can obtain the specific details of the user's electricity purchase needs, and the power company can only get more details after decrypting. The sum of each user's power purchase demand rather than the specific power purchase demand data of each user, which not only reduces the bandwidth occupation, but also reduces the computational complexity of decryption, and at the same time authenticates the identity of the sender, thus simplifying the system and effectively preventing This ensures that user privacy is disclosed, improves security and transmission efficiency, and protects the fairness of market transactions.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings that need to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a network structure diagram of a smart grid user electricity selling method based on homomorphic encryption in the present invention;

Fig. 2 is a working flow chart of a method for selling electricity to smart grid users based on homomorphic encryption in the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1 and Figure 2, a homomorphic encryption-based smart grid user electricity sales method of this embodiment is shown. The process includes the power company sending the electricity purchase request data to the community gateway, and the community gateway first verifies the electricity purchase request. After the data is correct, it is sent to n users. After the n users encrypt the power purchase demand data through homomorphic encryption, they send it to the community gateway. The community gateway sums the power purchase demand data of n users and sends it to the power Companies and power companies decrypt and restore the data after receiving the power purchase demand data uploaded by the community gateway. The community gateway and the user communicate under the smart meter communication network (AMI) based on the single-hop network topology (single-hop). Preferably, the communication between the power company and the community gateway is based on a 5G network.

Specifically, the specific steps of the smart grid user electricity selling method are as follows:

(1) System initialization:

The power company should choose some parameters, including the cyclic group G with order q, _GT and a bilinear pair to all set up; calculate Generate a homomorphic encryption public key pair (f, g) and the corresponding private key λ, where a, b are elements in the is the prime number group whose order is q, P and P ₀ are the elements in the cyclic group G;

The four hash functions include H ₁ : {0, 1} ^* → G, H ₃ : G _T ×G _T → {0, 1} ^* , {0, 1} ^* represents a set composed of binary sequences of arbitrary bit length; according to the selected parameters, the power company, gateway and user obtain their own private key respectively and public key.

The private key and public key in the above steps are generated as follows:

(a) Electric company ID _u from Randomly select an element sk _u as the private key, and calculate PK _u = sk _u P ₀ as the public key;

(b) Community gateway ID _g from Randomly select an element sk _g as the private key, and calculate PK _g = sk _g P ₀ as the public key;

(c) User ID _i from Randomly select an element sk _i as the private key, and calculate PK _i = sk _i P ₀ as the public key;

(d) The power company releases public parameters Among them, U and V are randomly selected elements in the cyclic group G.

(2) Power purchase request:

The power company sends power purchase request data to the community gateway, including the ID _u of the power company, the ID _g of the community gateway, price information Info _p , secret key r _u P ₀ , time stamp TS and signature σ _u .

(3) Community gateway verification:

When the community gateway receives the power purchase request data, it first verifies the authenticity and integrity of the data according to the timestamp TS and the signature _σu , and then sends it to each user in the community.

Specifically, the verification of price information Info _p , signature σ _u and power purchase request data in step (2) and step (3) is carried out as follows:

(a) Price information Info _p ={p ₁ , p ₂ ,...,p _k }, where k is the total number of time slots, and p is the electricity sale price in any time slot;

(b) Signature σ _u ＝sk _u H ₁ (ID _u ||ID _g ||Info _p ||r _u P ₀ ||TS), the community gateway uses σ _u to verify the authenticity and integrity of the power purchase request data ;

(d) After the community gateway receives the power purchase request data, it first verifies the timestamp TS, and then verifies the equation Whether it is established.

(4) User replies:

The user uses homomorphic encryption technology to cover up the real power purchase demand data to get Bi, and generates a digital signature σ _i and a message authentication code MAC(B _{i )} to reply to the community gateway.

Specifically, the process of covering up the real power purchase demand data is as follows:

(a) Calculate the secret key r _i is a random number, and r _g is a random number, and

(b) Using the homomorphic encryption algorithm to cover up the real power purchase demand data to obtain Then get the set B _i =(B _i,1 ,B _i,2 ,...,B _i,k ), where is a random number in the composite order group with order f ² , f is a prime number, b _{i, x} represent the real power purchase demand data;

(c) Generate message authentication code

(d) Generate a digital signature σ _i =sk _i H ₁ (H(k _i )||ID _g ||ID _u ||r _i P ₀ ||TS).

(5) Community gateway aggregation:

The community gateway aggregates the received power purchase demand data of all users, obtains the aggregated signature σ, aggregates the power purchase demand data B, the secret key group {r _i P ₀ }, and the message authentication code MAC _f , and sends it to the power company.

Specifically, community gateway aggregation is carried out according to the following process:

(a) Under the smart meter communication network (AMI) of the single-hop network topology (single-hop), the aggregated signature σ=∑ _1≤i≤n σ _i , n represents the number of users in this method;

(b) aggregate power purchase demand data in each time slot in Then get the set B=(B ⁽¹⁾ , B ⁽²⁾ ,..., B ^(k) ), (1≤x≤k), r _g is a random number, and

(c) Message authentication code MAC(B)=Π _1≤i≤n MAC(B _i ), meanwhile, the community gateway randomly selects an element R to obtain message authentication code MAC _f =(MAC ₁ , MAC ₂ ), where MAC ₂ =U ^H(B) V ^{H (R)} , where,

(6) Decryption by the power company:

After the power company receives the aggregated power purchase demand data sent by the community gateway, it decrypts the data and restores the power sales share b ^(x) and verifies it.

Specifically, the power company decrypts according to the following process:

(b) According to the homomorphic encryption algorithm, use the private key λ to restore the aggregated power purchase demand data of each time slot where L is function, x is the argument of the function;

(c) Verification Equation Whether it is established, and if it is established, the verification is passed;

(d) calculation And verification MAC ₂ ＝U ^H(B') V ^H(R') , B' is the aggregated power purchase demand data sent by the community gateway received by the power company,

The mathematical theory applied in this embodiment includes:

1. Bilinear pairing

In the present invention, bilinear pairing is a mapping that satisfies bilinearity, nondegenerateness, and computability, and it maps two elements in the prime order group to one element in the prime order group.

2. Hash function

A hash function is a one-way function that transforms an input of any length into a fixed-length output, which is called the hash value of the input. A secure hash function should satisfy: (1) The output length is fixed, generally at least 128 bits, to resist birthday attacks; (2) For each given input, its hash value can be easily calculated; (3) Given a description of a hash function and a hash value, it is computationally infeasible to find the corresponding input; (4) Given a description of a hash function, it is computationally infeasible to find two different inputs with the same hash value is computationally infeasible.

3. Homomorphic encryption

Homomorphic encryption is a cryptographic technique based on computational complexity theory of mathematical puzzles. Processing the homomorphically encrypted data yields an output that, when decrypted, yields the same output as the original unencrypted data. Computing first and then decrypting is equivalent to decrypting and then computing. Using homomorphic encryption technology, multiple ciphertexts can be calculated first and then decrypted. It is not necessary to decrypt each ciphertext and spend a high calculation cost. It can be realized that the decryption party can only obtain the final result and cannot obtain each ciphertext. news.

The entire smart grid user electricity sales method based on homomorphic encryption uses hash function, bilinear pairing, and homomorphic encryption to cover up the user's real electricity purchase demand data, and authenticate the identity of the data sender, so that Neither the community gateway nor the power company other than the user can obtain the user's specific power purchase demand data, which effectively prevents the user's privacy from being disclosed and protects the fairness of market transactions.

The present invention has been further described above with the help of specific embodiments, but it should be understood that the specific description herein should not be construed as limiting the spirit and scope of the present invention. Various modifications made in the embodiments all belong to the protection scope of the present invention.

Claims (8)

1. a kind of smart power grid user sale of electricity method based on homomorphic cryptography, it is characterised in that：Utilities Electric Co. is by power purchase number of request According to community's gateway is sent to, each user is issued to after gateway priori card power purchase request data in community's is errorless, user needs power purchase After asking data to be encrypted by the method for homomorphic cryptography, it is sent to community's gateway, community's gateway is by the power purchase demand of each user It is sent to Utilities Electric Co. after data summation, Utilities Electric Co. receives after community network shuts the power purchase demand data of biography and carries out decryption restoration Data；

Specifically include following steps：

(1) system initialization：

Utilities Electric Co. should choose some parameters, including cyclic group G, G that rank is q_TAn and Bilinear mapTo allIt sets up；It calculatesProduction Give birth to a homomorphic cryptography public key is to (f, g) and corresponding private key λ, wherein a, bIn element,The prime number for being q for rank Group, P, P₀For the element in cyclic group G；

Four hash functions includeH₁：{ 0,1 }^*→ G,H₃：G_T×G_T→ { 0,1 }^*, { 0,1 }^*Indicate the set of the binary sequence composition of arbitrary bit long；According to the parameter of selection, Utilities Electric Co., gateway and use Family respectively obtains the private key and public key of oneself；

(2) power purchase is asked：

Utilities Electric Co. sends power purchase request data to community's gateway, includes the identity ID of Utilities Electric Co._u, community's gateway identity ID_g, pricing information Info_p, secret key r_uP₀, time stamp T S and signature sigma_u；

(3) community's gateway authentication

After when community, gateway receives power purchase request data, first according to time stamp T S and signature sigma_uThe authenticity of verify data and complete Property, each user being then forwarded in community；

(4) user replys：

User covers true power purchase demand data using homomorphic cryptography technology and obtains B_i, and generate digital signature σ_iDifferentiate with message Code MAC (B_i) backward community network close reply；

(5) community's gateway polymerize：

The power purchase demand data of all users received polymerize by community's gateway, the signature sigma being polymerize, and polymerize power purchase demand number According to B, secret key group { r_iP₀And Message Authentication Code MAC_f, sent to Utilities Electric Co.；

(6) Utilities Electric Co. decrypts：

After Utilities Electric Co. receives the polymerization power purchase demand data that community's gateway is sent, data are decrypted and restore sale of electricity share b^(x)And it verifies.

2. a kind of smart power grid user sale of electricity method based on homomorphic cryptography as described in claim 1, which is characterized in that community Gateway with user is led in the intelligent electric meter communication network (AMI) based on single-hop networks topological structure (single-hop) News.

3. a kind of smart power grid user sale of electricity method based on homomorphic cryptography as claimed in claim 2, which is characterized in that electric power It is to be communicated based on 5G networks between company and community's gateway.

4. a kind of smart power grid user sale of electricity method based on homomorphic cryptography as claimed in claim 3, which is characterized in that wherein Private key and public key in step (1), generate as follows：

(a) Utilities Electric Co. ID_uFromIn arbitrarily select an element sk_uAs private key, and calculate PK_u=sk_uP₀As public key；

(b) community's gateway ID_gFromIn arbitrarily select an element sk_gAs private key, and calculate PK_g=sk_gP₀As public key；

(c) User ID_iFromIn arbitrarily select an element sk_iAs private key, and calculate PK_i=sk_iP₀As public key；

(d) the open parameter of Utilities Electric Co.'s publication

Wherein U, V are to be selected at random in cyclic group G The element taken.

5. a kind of smart power grid user sale of electricity method based on homomorphic cryptography as claimed in claim 4, which is characterized in that wherein Step (2) and the pricing information Info in step (3)_p, signature sigma_uAnd to the verification of power purchase request data as follows into Row：

(a) pricing information Info_p={ p₁, p₂..., p_k, wherein k is total number of timeslots, and p is the sale of electricity price in any time slot；

(b) signature sigma_u=sk_uH₁(ID_u||ID_g||Info_p||r_uP₀| | TS), community gateway σ_uTo verify power purchase request data Authenticity and integrity；

(d) after community's gateway receives power purchase request data, time stamp T S is first verified, verifies equation laterIt is whether true.

6. a kind of smart power grid user sale of electricity method based on homomorphic cryptography as claimed in claim 5, which is characterized in that wherein The true power purchase demand data of cover in step (4), process carry out as follows：

(a) secret key is calculatedr_iFor One random number, andr_gFor a random number, and

(b) it applies homomorphic encryption algorithm to cover true power purchase demand data to obtainSet B is obtained later_i=(B_{I, 1}, B_{I, 2}..., B_{I, k}), InBe rank be f²Conjunction number rank group in a random number, f is a prime number, b_{I, x}Indicate true power purchase demand data；

(c) Message Authentication Code is generated

(d) digital signature σ is generated_i=sk_iH₁(H(k_i)||ID_g||ID_u||r_iP₀||TS)。

7. a kind of smart power grid user sale of electricity method based on homomorphic cryptography as claimed in claim 6, which is characterized in that wherein Community's gateway polymerization in step (5), carries out as follows：

(a) under the intelligent electric meter communication network (AMI) of single-hop networks topological structure (single-hop), the signature sigma of polymerization= ∑_1≤i≤nσ_i, n indicates the quantity of user in this method；

(b) each time slot polymerize power purchase demand dataWherein It obtains later Set B=(B⁽¹⁾, B⁽²⁾..., B^(k)), (1≤x≤k), r_gFor a random number, and

(c) Message Authentication Code MAC (B)=Π_1≤i≤nMAC(B_i), meanwhile, gateway arbitrarily one element R of selection in community's obtains message Authentication code MAC_f=(MAC₁, MAC₂), wherein MAC₂=U^H(B)V^H(R), In,

8. a kind of smart power grid user sale of electricity method based on homomorphic cryptography as claimed in claim 7, which is characterized in that wherein Utilities Electric Co.'s decryption carries out as follows in step (6)：

(a)

(b) each time slot polymerization power purchase demand data is restored with private key λ according to homomorphic encryption algorithmWherein L isFunction, x For the argument of function；

(c) equation is verifiedWhether It sets up, if so, then it is verified；

(d) it calculatesWith verification MAC₂=U^H(B’)V^H(R’), B ' is Utilities Electric Co. The polymerization power purchase demand data that the community's gateway received is sent,