KR20210066509A - Cross authentication method in remote metering system including smart meters, data collection unit and authentication server - Google Patents

Abstract

The present invention relates to a mutual authentication method in a remote meter reading system including a smart meter, a data collection device, and an authentication server. The remote meter reading system includes the smart meter, the data collection device, and the authentication server. Therefore, the present invention enables the smart meter and the data collection device to effectively authenticate each other in the remote meter reading system.

Description

CROSS AUTHENTICATION METHOD IN REMOTE METERING SYSTEM INCLUDING SMART METERS, DATA COLLECTION UNIT AND AUTHENTICATION SERVER

The present invention relates to a remote meter reading system, and more particularly, to a mutual authentication method in a remote meter reading system including a smart meter, a data collection device, and an authentication server.

Research on a smart grid system that can efficiently supply power by applying information and communication technology to the existing power grid is being actively conducted to identify power generation and consumption.

AMI (Advanced Metering Infrastructure) is a core technology that makes it possible to predict power demand by collecting necessary information from a smart grid system. In the existing meter reading method, a power meter reader visits a household and directly checks the power consumption of the watt-hour meter, but in the AMI, a smart meter automatically reads the power usage and transmits the information through the communication network.

These AMIs are mainly composed of a smart meter, a data concentration unit (DCU), and a meter data management system (MDMS).

A smart meter is a power meter that has a communication function with the outside. In the previous power meter, a person had to directly check the power level by looking at the power meter, but the smart meter has a communication function, so data such as power usage can be transmitted to the power company, etc. can be transmitted to the power provider.

The data concentrator collects and stores data such as power usage from a number of smart meters and transmits it to the power provider.

The weighing data management system is a system that comprehensively collects, verifies, statistic, and analyzes weighing data, provides necessary information to other systems, and executes AMI control commands such as power outage, power recovery, and on-demand meter reading.

However, these AMI systems are vulnerable to information security, such as being exposed to hacking attacks because they are based on open two-way communication, unlike the existing power grid.

The technical problem to be achieved by the present invention is an authentication method suitable for an AMI environment, in which a smart meter and a data collection device can effectively authenticate each other in a remote meter reading system including a smart meter, a data collection device, and an authentication server. It is intended to provide a mutual authentication method.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In a mutual authentication method in a remote meter reading system including a smart meter, a data collection device, and an authentication server according to the present invention for solving the above technical problem, (S1) the authentication server includes a first private key (msk) and the generating a _{first public key (G TA} ) corresponding to the first private key (msk); (S2) generating, by the data collection device, a second private key (sk _D ) and a second public key (G _D ) corresponding to the second private key (sk _D); (S3) generating, by the smart meter, a third private key (sk _M ) and a third public key (G _M ) corresponding to the third private key (sk _M); (S4) generating, by the data collection device, a first random number (k _D ) and a fourth public key (U _D ) corresponding to the first random number (k _{D );} (S5) transmitting, by the data collection device, an ID (ID _DCU ) of the data collection device and the fourth public key (U _D ) to the smart meter; (S6) generating, by the smart meter, a second random number (k _M ) and a fifth public key (U _M ) corresponding to the second random number (k _{M );} (S7) the smart meter _combines the ID (ID DCU) of the data collection device, the ID (ID _M ) of the smart meter, the fourth public key (U _D ), and the fifth public key (U _M ) to generate a first message (m _{M );} (S8) to produce a first electronic signature value (σ _M) to the digital signature to the third private key (sk _M) to which the smart meters, the first message _(M m); (S9) the smart meter transmitting the ID (ID _M ) of the smart meter, the fifth public key (U _M ), and the first digital signature value (σ _M ) to the data collection device; (S10) the data collection device ID (ID _DCU ) of the data collection device, the ID (ID _M ) of the smart meter, the fourth public key (U _D ), the fifth public key (U _M ), and generating a second message (m) by combining the second public key (G _{D );} (S11) transmitting, by the data collection device, an ID (ID _DCU ) of the data collection device and the second message (m) to the authentication server; (S12) the authentication server uses the ID (ID _DCU ) of the data collection device, the second public key (G _D ), the ID (ID _M ) of the smart meter, and the third public key (G _M ) to verify the data collection device and the smart meter; (S13) generating, by the authentication server, a second digital signature value (τ) by digitally signing the second message (m) with the first private key (msk); (S14) transmitting, by the authentication server, the second digital signature value (τ) and the third public key (G _M ) to the data collection device; (S15) verifying, by the data collection device, the first digital signature value (σ _M ) using the third public key (G _{M );} (S16) When the data collection device _{verifies the first digital signature value (σ M ), the third message (m D} ) by combining the second digital signature value (τ) with the second message (m) creating a; (S17) generating, by the data collection device, a third digital signature value (σ _D ) by _{digitally signing the third message (m D} ) with the second private key (sk _{D );} (S18) transmitting, by the data collection device, the third message (m _D ) and the third digital signature value (σ _D ) to the smart meter; (S19) the smart meter extracting the second public key (G _D ) and the second digital signature value (τ) _{from the third message (m D );} (S20) the smart meter verifying the third digital signature value (σ _D ) using the second public key (G _D ); (S21) the smart meter, when the third digital signature value (σ _D ) is verified, verifying the second digital signature value (τ) using the first public key (G _TA ); (S22) The smart meter generates an authentication key (K) by using _{the second random number (k M} ) and the fourth public key (U _D ) when the second digital signature value (τ) is verified step; (S23) generating, by the data collection device, the same authentication key (K) as in step S22 by using _{the first random number (k D} ) and the fifth public key (U _{M );} (S24) generating, by the smart meter, a session key (k) from the authentication key (K) using a key derivation function; and (S25) generating, by the data collection device, the same session key (k) as in step S24 by using a key derivation function from the authentication key (K).

Before the step S1, the authentication server further comprises the step of defining an elliptic curve (G), the step S2 generates _{the second public key (G D ) using the elliptic curve (G),} The step S3 generates the third public key G _M using the elliptic curve G, and the step S4 generates the fourth public key U _{D using the elliptic curve G} And, in the step S6, the fifth public key (U _M ) may be generated using the elliptic curve (G).

The step S8, the step S13, and the step S17 may be digitally signed using an elliptic curve digital signature algorithm.

The mutual authentication method includes the steps of (S26) transmitting, by the data collection device, an ID (ID _DCU ) of the data collection device to the smart meter and a power amount data request message (Request); (S27) generating, by the smart meter, an wattage message (M) by combining an _{ID (ID M ) of the smart meter and wattage data (Message);} (S28) generating an encrypted message (C) by encrypting the power amount message (M) with the session key (k) by the smart meter; (S29) generating, by the smart meter, the power amount message (M) with the third private key (sk _M ) to generate a fourth digital signature value (σ); (S30) the smart meter transmitting the ID (ID _M ) of the smart meter, the encrypted message (C), and the fourth digital signature value (σ) to the data collection device; (S31) the data collection device decrypting the encrypted message (C) with the session key (k) to obtain the wattage message (M); and (S32) verifying, by the data collection device, the fourth digital signature value (σ) using the third public key (G _{M ).}

According to the present invention described above, as an authentication method suitable for an AMI environment, a smart meter and a data collection device can effectively authenticate each other in a remote meter reading system including a smart meter, a data collection device, and an authentication server. An authentication method may be provided.

Effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 shows the configuration of a remote meter reading system according to an embodiment of the present invention.
2A to 2C are flowcharts illustrating a process in which a smart meter, a data collection device, and an authentication server authenticate each other in a mutual authentication method of a remote meter reading system according to an embodiment of the present invention.
3 is a flowchart illustrating a process of transmitting and receiving data between a smart meter and a data collection device in a mutual authentication method of a remote meter reading system according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description and the accompanying drawings, substantially identical components are denoted by the same reference numerals, respectively, and thus redundant descriptions will be omitted. In addition, in the description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted.

1 shows the configuration of a remote meter reading system according to an embodiment of the present invention. The remote meter reading system according to the present embodiment includes a plurality of smart meters 10_1 , 10_2 , 10_3 , ... , a data collection device 20 , and an authentication server 30 .

The smart meters 10_1, 10_2, 10_3, ... are installed inside and outside the building of the customer to measure the user's power consumption and transmit it to the data collection device 20 .

The data collection device 20 collects and stores data such as power usage from the smart meters 10_1, 10_2, 10_3, ..., and transmits it to a metering data management system (not shown) of the power provider.

The authentication server 30 is operated by a trusted organization (eg, a power provider or a subject requested from a power provider), and as will be described later, the data collection device 20 and the smart meters 10_1, 10_2, 10_3, .. .) provides settings for mutual authentication between

In an embodiment of the present invention, the smart meters 10_1, 10_2, 10_3, ... are implemented with relatively low-power and low-spec hardware compared to the data collection device 20 or the authentication server 30 . For example, the data collection device 20 or the authentication server 30 is implemented with hardware of at least PC specification, whereas the smart meters 10_1, 10_2, 10_3, ...) have flash memory of less than 512 Kbytes and less than 64k, for example. It can have relatively low computing power, such as SRAM.

Also, in the embodiment of the present invention, the data collection device 20 and the metering data management system or the authentication server 30 are connected through an Ethernet network with a low error rate and high speed, but the smart meters 10_1, 10_2, 10_3, . ..) and the data acquisition device 20 have a high error rate and a slow speed compared to Ethernet communication environments such as power line communication networks (eg, RS-485, RS-232, etc.) and low-power-based wireless communication (eg, RF800, LoRA, etc.) connected through a communication network.

Therefore, the authentication method in the remote meter reading system according to the embodiment of the present invention provides a low-quality communication environment between the smart meters 10_1, 10_2, 10_3, ... and the data collection device 20 and the smart meters ( 10_1, 10_2, 10_3, ...) suitable for low computing power is required.

In the following description, the smart meter 10 will be described as representative of the smart meters 10_1, 10_2, 10_3, ... for convenience.

2A to 2C are flowcharts illustrating a process in which the smart meter 10, the data collection device 20, and the authentication server 30 authenticate each other in the mutual authentication method of the remote meter reading system according to an embodiment of the present invention. . For convenience, one smart meter 10 will be exemplified, but the mutual authentication method according to the present embodiment may be simultaneously performed for several smart meters 10_1, 10_2, 10_3, ...).

The smart meter 10 has an ID (ID _M ), and the data collection device 20 has an ID (ID _DCU ).

Referring to FIG. 2A , in step 210 , the authentication server 30 defines an elliptic curve G for elliptic curve encryption. The elliptic curve G is shared with the data collection device 20 and the smart meter 10 .

In step 211, the authentication server 30 generates a first private key msk that is the private key of the authentication server 30, and uses the elliptic curve G to generate a first first private key msk corresponding to the first private key msk. Generate a public key (G _{TA ).} The first public key (G _TA ) of the authentication server 30 is shared with the smart meter 10 .

_{In step 212, the data collection device 20 generates a second private key (sk D} ) which is the private key of the data collection device 20, and uses the elliptic curve (G) to obtain the second private key (sk _D ). A corresponding second public key (G _D ) is generated.

_{In step 213, the smart meter 10 generates a third private key (sk M} ), which is the private key of the smart meter 10, and uses the elliptic curve (G) to _{correspond to the third private key (sk M} ). A third public key (G _M ) is generated.

In step 214 , the data collection device 20 generates _{a first random number k D} for Diffie-Hellman key exchange with the smart meter 10 . Expressed in water code, it is as follows.

In step 215 , the data collection device 20 generates a fourth public key U _{D that is an arbitrary public key corresponding to the first random number k D using the elliptic curve G .} Expressed in water code, it is as follows.

In step 216 , the data collection device 20 transmits the ID (ID _DCU ) and the fourth public key (U _D ) of the data collection device 20 to the smart meter 10 .

In step 217 , the smart meter 10 generates _{a second random number k M} for Diffie-Hellman key exchange with the data collection device 20 . Expressed in water code, it is as follows.

In step 218 , the smart meter 10 generates a fifth public key U _{M which is an arbitrary public key corresponding to the second random number k M using the elliptic curve G .} Expressed in water code, it is as follows.

In step 219, the smart meter 10 is the ID (ID _DCU ) of the data collection device 20, the ID (ID _M ) of the smart meter 10, the fourth public key (U _D ), the fifth public key (U) _M ) is combined to generate a first message (m _{M ).} Expressed in water code, it is as follows.

In step 220, the smart meter 10 generates a first message _(M m), the first electronic signature value and the digital signature to his private key, the third private key (sk _M) (σ _M). Expressed in water code, it is as follows.

Here, ECDSA stands for Elliptic Curve Digital Signature Algorithm.

In step 221 , the smart meter 10 transmits the ID _M of the smart meter 10 , the fifth public key U _M , and the first digital signature value σ _M to the data collection device 20 . .

Referring now to Figure 2b, in step 222, the data collection device 20 ID (ID _DCU ) of the data collection device 20, the ID (ID _M ) of the smart meter 10, the fourth public key (U _D) ), a fifth public key (U _M ), and a second public key (G _D ) are combined to generate a second message (m). Expressed in water code, it is as follows.

In step 223 , the data collection device 20 transmits the ID _DCU of the data collection device 20 and the second message m to the authentication server 30 through a secure channel.

In step 224, the authentication server 30 is the ID (ID _DCU ) of the data collection device 20, the second public key (G _D ), the ID (ID _M ) of the smart meter 10, the third public key (G) _M ) is used to verify the data collection device 20 and the smart meter 10 . Expressed in water code, it is as follows.

For example, when the ID (ID _DCU ) and the second public key (G _D ) of the data collection device 20 match, and the ID (ID _M ) of the smart meter 10 and the third public key (G _M ) match , the data collection device 20 and the smart meter 10 are verified.

In step 225, the authentication server 30 digitally signs the second message m with its own private key, msk, to generate a second digital signature value τ. Expressed in water code, it is as follows.

In step 226 , the authentication server 30 transmits the second digital signature value τ and the third public key G _M of the smart meter 10 to the data collection device 20 through a secure channel.

In step 227, the data collection device 20 converts the first digital signature value (σ _M ) of the smart meter 10 (see step 220) to the third of the smart meter 10 for verification of the smart meter 10 . It is verified using the public key (G _{M ).} If the verification fails in step 228, the process is stopped (step 229). Expressed in water code, it is as follows.

If the verification is successful in step 228, in step 230, the data collection device 20 combines the second digital signature value (τ) of the authentication server 30 to the second message (m) to the third message (m _D ) create Expressed in water code, it is as follows.

Referring now to FIG. 2C , in step 231 , the data collection device 20 _{digitally signs the third message m D} with a second private key sk _D that is its own private key to digitally sign the third digital signature value σ _D ) is created. Expressed in water code, it is as follows.

In step 232 , the data collection device 20 transmits the third message m _D and the third digital signature value σ _D to the smart meter 10 .

In step 233 , the smart meter 10 _{extracts the second public key G D} of the data collection device 20 and the second digital signature value τ of the authentication server 30 _{from the third message m D .} do.

In step 234 , the smart meter 10 transmits the third digital signature value σ _D (see step 231 ) of the data collection device 20 to the data collection device 20 for verification of the data collection device 20 . It is verified using the second public key (G _{D ).} If the verification fails in step 235, the process is stopped (step 236). Expressed in water code, it is as follows.

If the verification is successful in step 235, in step 237, the smart meter 10 sends the second digital signature value τ of the authentication server 30 (see step 225) to the authentication server for verification of the authentication server 30. It is verified using the first public key (G _{TA ) of (30).} If the verification fails in step 238, the process is stopped (step 239). Expressed in water code, it is as follows.

If the verification is successful in step 238, in step 240, the smart meter 10 provides a fourth public key (U _D ), a fifth public key (U _M ), a second random number (k _M ), and a fourth public key (U). _D ) is used to generate an authentication key (K). For example, the fourth public key (U _D ), the fifth public key (U _M ), and the second random number (k _M ) multiplied by the fourth public key (U _D ) are combined and hashed to obtain the authentication key (K). create Expressed in water code, it is as follows.

In step 241 , the data collection device 20 uses the fourth public key (U _D ), the fifth public key (U _M ), the first random number (k _D ), and the fifth public key (U _M ) as an authentication key (K) is generated. For example, the fourth public key (U _D ), the fifth public key (U _M ), and the first random number (k _D ) multiplied by the fifth public key (U _M ) are combined and hashed to obtain the authentication key (K). create Expressed in water code, it is as follows.

The same authentication key (K) is generated in steps 240 and 241 by the Diffie-Hellman algorithm.

In step 242, the smart meter 10 generates a session key k by using a key derivation function (KDF) from the authentication key K. Expressed in water code, it is as follows.

In step 243, the data collection device 20 generates a session key k by using a key derivation function (KDF) from the authentication key K. Expressed in water code, it is as follows.

Since the authentication key (K) is the same, the same session key (k) is generated in steps 242 and 243.

3 is a flowchart illustrating a process in which data is transmitted/received between a smart meter and a data collection device in a mutual authentication method of a remote meter reading system according to an embodiment of the present invention.

Through the process of FIG. 2 , the data collection device 20 and the smart meter 10 have the same session key k.

In step 310 , the data collection device 20 transmits an ID (ID _DCU ) of the data collection device 20 to the smart meter 10, and a power amount data request message (Request).

In step 311 , the smart meter 10 combines the ID (ID _DCU ) of the data collection device 20, the ID (ID _M ) of the smart meter 10, and the wattage data (Message) to generate a wattage message (M) do. Expressed in water code, it is as follows.

In step 312, the smart meter 10 generates an encrypted message (C) by encrypting the wattage message (M) with the session key (k). Expressed in water code, it is as follows.

In step 313 , the smart meter 10 digitally signs the wattage message M with its own private key, a third private key sk _M , to generate a fourth digital signature value σ. Expressed in water code, it is as follows.

In step 314 , the smart meter 10 transmits the ID _M of the smart meter 10 , the encrypted message C, and the fourth digital signature value σ to the data collection device 20 .

In step 315, the data collection device 20 decrypts the encrypted message (C) with the session key (k) to obtain the wattage message (M). Expressed in water code, it is as follows.

In step 316 , the data collection device 20 converts the fourth digital signature value (σ) of the smart meter 10 to the third of the smart meter 10 of the smart meter 10 in order to verify the smart meter 10 . It is verified using the public key (G _{M ).} Expressed in water code, it is as follows.

Meanwhile, the above-described embodiments of the present invention can be written as a program that can be executed on a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium. The computer-readable recording medium includes a storage medium such as a magnetic storage medium (eg, a ROM, a floppy disk, a hard disk, etc.) and an optically readable medium (eg, a CD-ROM, a DVD, etc.).

Embodiments of the present invention may be represented by functional block configurations and various processing steps. These functional blocks may be implemented in any number of hardware and/or software configurations that perform specific functions. For example, an embodiment may be an integrated circuit configuration, such as memory, processing, logic, look-up table, etc., capable of executing various functions by means of control of one or more microprocessors or other control devices. can be hired Similar to how components of the present invention may be implemented as software programming or software components, embodiments may include various algorithms implemented as data structures, processes, routines, or combinations of other programming constructs, including C, C++ , Java, assembler, etc. may be implemented in a programming or scripting language. Functional aspects may be implemented in an algorithm running on one or more processors. Further, embodiments may employ prior art for electronic configuration, signal processing, and/or data processing, and the like. Terms such as “mechanism”, “element”, “means” and “configuration” may be used broadly and are not limited to mechanical and physical configurations. The term may include the meaning of a series of routines of software in association with a processor or the like.

The specific implementations described in the embodiment are only embodiments, and do not limit the scope of the embodiment in any way. For brevity of the specification, descriptions of conventional electronic components, control systems, software, and other functional aspects of the systems may be omitted. In addition, the connections or connecting members of the lines between the components shown in the drawings illustratively represent functional connections and/or physical or circuit connections, and in actual devices, various functional connections, physical connections that are replaceable or additional may be referred to as connections, or circuit connections. In addition, unless there is a specific reference such as "essential" or "importantly", it may not be a necessary component for the application of the present invention.

So far, with respect to the present invention, the preferred embodiments have been looked at. Those of ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments are to be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

Claims (4)

A method for mutual authentication in a remote meter reading system comprising a smart meter, a data collection device, and an authentication server, the method comprising:
(S1) generating, by the authentication server, a first private key (msk) and a first public key (G _TA ) corresponding to the first private key (msk);
(S2) generating, by the data collection device, a second private key (sk _D ) and a second public key (G _D ) corresponding to the second private key (sk _D);
(S3) generating, by the smart meter, a third private key (sk _M ) and a third public key (G _M ) corresponding to the third private key (sk _M);
(S4) generating, by the data collection device, a first random number (k _D ) and a fourth public key (U _D ) corresponding to the first random number (k _{D );}
(S5) transmitting, by the data collection device, an ID (ID _DCU ) of the data collection device and the fourth public key (U _D ) to the smart meter;
(S6) generating, by the smart meter, a second random number (k _M ) and a fifth public key (U _M ) corresponding to the second random number (k _{M );}
(S7) the smart meter _combines the ID (ID DCU) of the data collection device, the ID (ID _M ) of the smart meter, the fourth public key (U _D ), and the fifth public key (U _M ) to generate a first message (m _{M );}
(S8) to produce a first electronic signature value (σ _M) to the digital signature to the third private key (sk _M) to which the smart meters, the first message _(M m);
(S9) the smart meter transmitting the ID (ID _M ) of the smart meter, the fifth public key (U _M ), and the first digital signature value (σ _M ) to the data collection device;
(S10) the data collection device ID (ID _DCU ) of the data collection device, the ID (ID _M ) of the smart meter, the fourth public key (U _D ), the fifth public key (U _M ), and generating a second message (m) by combining the second public key (G _{D );}
(S11) transmitting, by the data collection device, an ID (ID _DCU ) of the data collection device and the second message (m) to the authentication server;
(S12) the authentication server uses the ID (ID _DCU ) of the data collection device, the second public key (G _D ), the ID (ID _M ) of the smart meter, and the third public key (G _M ) to verify the data collection device and the smart meter;
(S13) generating, by the authentication server, a second digital signature value (τ) by digitally signing the second message (m) with the first private key (msk);
(S14) transmitting, by the authentication server, the second digital signature value (τ) and the third public key (G _M ) to the data collection device;
(S15) verifying, by the data collection device, the first digital signature value (σ _M ) using the third public key (G _{M );}
(S16) When the data collection device _{verifies the first digital signature value (σ M} ), the second message (m) combines the second digital signature value (τ) to a third message (m _D ) creating a;
(S17) generating, by the data collection device, a third digital signature value (σ _D ) by _{digitally signing the third message (m D} ) with the second private key (sk _{D );}
(S18) transmitting, by the data collection device, the third message (m _D ) and the third digital signature value (σ _D ) to the smart meter;
(S19) the smart meter extracting the second public key (G _D ) and the second digital signature value (τ) _{from the third message (m D);}
(S20) the smart meter verifying the third digital signature value (σ _D ) using the second public key (G _D );
(S21), by the smart meter, if the third digital signature value (σ _D ) is verified, verifying the second digital signature value (τ) using the first public key (G _TA );
(S22) The smart meter generates an authentication key (K) by using _{the second random number (k M} ) and the fourth public key (U _D ) when the second digital signature value (τ) is verified step;
(S23) generating, by the data collection device, the same authentication key (K) as in step S22 using _{the first random number (k D} ) and the fifth public key (U _{M );}
(S24) generating, by the smart meter, a session key (k) from the authentication key (K) using a key derivation function; and
(S25) The mutual authentication method comprising the step of generating, by the data collection device, the same session key (k) as in step S24 by using a key derivation function from the authentication key (K). According to claim 1,
Before the step S1, the authentication server further comprises the step of defining an elliptic curve (G),
In the step S2, the second public key (G _D ) is generated using the elliptic curve (G),
The step S3 generates _{the third public key (G M} ) using the elliptic curve (G),
In the step S4, the fourth public key U _D is generated using the elliptic curve G,
The step S6 is a mutual authentication method, characterized in that _{the fifth public key (U M} ) is generated by using the elliptic curve (G). 3. The method of claim 2,
The step S8, the step S13, and the step S17 are mutual authentication method, characterized in that digital signature is performed using an elliptic curve digital signature algorithm. According to claim 1,
(S26) transmitting, by the data collection device, an ID (ID _DCU ) of the data collection device, and a wattage data request message (Request) to the smart meter;
(S27) generating, by the smart meter, an wattage message (M) by combining an _{ID (ID M ) of the smart meter and wattage data (Message);}
(S28) generating an encrypted message (C) by encrypting the power amount message (M) with the session key (k) by the smart meter;
(S29) generating, by the smart meter, the power amount message (M) with the third private key (sk _M ) to generate a fourth digital signature value (σ);
(S30) the smart meter transmitting the ID (ID _M ) of the smart meter, the encrypted message (C), and the fourth digital signature value (σ) to the data collection device;
(S31) the data collection device decrypting the encrypted message (C) with the session key (k) to obtain the wattage message (M); and
(S32) Mutual authentication method, characterized in that it further comprises the step of verifying, by the data collection device, the fourth digital signature value (σ) using the third public key (G _{M ).}

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