CN106211136B

CN106211136B - Naming-based secure communication method in smart power grid

Info

Publication number: CN106211136B
Application number: CN201610795483.8A
Authority: CN
Inventors: 伍军; 郭龙华; 韩为祎; 李建华; 陈璐艺; 郭小贤
Original assignee: Shanghai Heyou Information Technology Co ltd; Shanghai Pengyue Jinghong Information Technology Development Co ltd; Shanghai Jiaotong University
Current assignee: Shanghai Heyou Information Technology Co ltd; Shanghai Pengyue Jinghong Information Technology Development Co ltd; Shanghai Jiaotong University
Priority date: 2016-08-31
Filing date: 2016-08-31
Publication date: 2021-07-13
Anticipated expiration: 2036-08-31
Also published as: CN106211136A

Abstract

The invention provides a naming-based safe communication-method in a smart grid, which applies a wireless network, has safe service, is suitable for communication of a non-TCP/IP protocol, transmits data from a data link layer to a presentation layer through naming, routing and caching processes of an ICN, and specifically comprises the following steps: step 1: after communication is established, a data object (NDO source) is appointed to issue the NDO to a network; step 2: the receiver subscribes according to the NDO requirement; and step 3: the docking system constructs a matching publishing platform; and 4, step 4: the docking system constructs a matching subscription platform; and 5: generating a forwarding identifier FI by using the scope identifier SI used for naming the NDO and the convergence identifier RI, and sending the FI to the NS; step 6: according to FI, NDO is transported to NS via PSIRP. The invention enhances the safety performance and improves the communication efficiency, and is suitable for data sharing in a dispersed large-scale smart power grid.

Description

Naming-based secure communication method in smart power grid

Technical Field

The invention relates to a naming-based secure communication method in a smart power grid.

Background

With the rapid development of the internet, the current network based on the TCP/IP protocol cannot adapt to the development requirement well, and the problems of expandability, mobility, security and the like need to be solved. Network architectures that are no longer based on the TCP/IP protocol, such as Information Centric Networking (ICN), have become a trend for next generation networks. As an idea in a future power grid infrastructure, the smart power grid has high efficiency, reliability and safety under the support of modern communication technologies such as automatic control and wireless networks. The IEC61850 standard is widely used in substation communication networks. In addition, part of the protocols in the IEC61850 standard, such as Sampled Values (SVs), generic object-oriented substation events (GOOSE), etc., are not based on TCP/IP architecture. The IEC61850 standard is based on an intelligent substation, and uses wireless network communication, so that interoperability and interconnectivity of substation equipment are greatly improved. However, as the number of Intelligent Electronic Device (IED) nodes increases and openness develops, new efficiency, reliability and security challenges ensue, particularly in wireless networks.

IEC61850 was proposed by IEC in 1995 and promulgated by IEC TC57 in 2004. The hierarchy, method and protocol of communication between IEDs is defined in IEC 61850. In addition, data objects, formats and configuration languages are also designed in the substation. The transfer of information obtained from the feeders and equipment is based on SAV, GOOSE and MMS communication protocols. Messages are sent to the message queue and received by an Abstract Communication Service Interface (ACSI) Service through a Specific Communication Service Mapping (SCSM). ACSI is not dependent on the following system. The communication application is completed based on the ACSI service. Some research work on substation wireless networks has demonstrated its performance with the latency requirements specified in IEC61850 part 5. The wireless network occupies low installation cost, can provide enough data rate and can be freely scheduled in a smart grid with large-scale content distribution.

Current network architectures have been proposed and operated for decades, and there are problems with the development of various communication requirements. To address these issues, the advent of ICNs is a hope for future network architectures. The ICN names the information at the network layer and efficiently and timely delivers the information to the user through caching and multicasting mechanisms within the network. The ICN adopts a protocol stack architecture based on information naming to replace the traditional TCP/IP-based architecture. IP addresses work only when signing is transported locally. The user sends a request to the network and is likely to have a response from the cache. In IP-based networks, information security is closely related to the security of the host. However, ICNs provide security protection towards the information itself and enable higher fine-grained security. Just like a fund item in EU FP7, publish-subscribe internet routing model (PSIRP) is a very popular approach in ICNs. The PSIRP project is directed to developing an information centric network architecture that implements and validates a publish-subscribe based schema, which may be one of the most promising approaches to address many of the challenges and problems in current networks. Among these, the most important concept is the Named Data Object (NDO).

As shown in table 1, GOOSE and SV in IEC61850 standard make a publish/subscribe communication model. PSIRP is a method of establishing a publish/subscribe pattern in ICN that is notified when resources are available after clients register for subscriptions. In communication, this has high scalability. GOOSE and SV are only concerned with the physical layer and the data link layer in conformity with the naming-based ICN design. The introduction of ICNs may enhance the security performance of IEC61850 based communication in smart grids.

TABLE 1 comparison of IEC61850 and ICN

The IEC61850 standard is one of the important standards for substation automation and live operating systems, and defines the semantic entities of devices and equipment. A large number of Intelligent Electronic Devices (IEDs) have Substation Automation Systems (SAS) to collect, monitor and process power data. In IEC61850, SAS is divided into three levels, including a process layer, an intermediate layer and a substation layer. Part of the communication protocols in the IEC61850 standard are also not based on TCP/IP protocols, such as SV and GOOSE in process level network communication. For SAS, the reliability and security of the process level network is very important because it is the only network connecting the process and intermediate layers. The IEC61850 standard supports independence of applications by a standard model and achieves high issuability of communication in SAS.

With the continuous evolution and development of network attacks, SAS is exposed to interoperability, system function openness, and security threats from wireless network environments. Accidents due to safety issues of IEC61850 have reportedly caused significant losses. The safety of a substation based on the IEC61850 standard depends on one specific location. Private information of grid users may be leaked. An illegal or malicious node may issue some illegal, incorrect information. In addition, the conventional IEC61850 network is inefficient at data expansion. Due to the application of a wireless network and the increase of IED nodes, the IEC61850 smart grid can be attacked by Dos and other attacks. Meanwhile, SV and GOOSE are required for real-time communication. The strict time requirements limit the use of heavyweight security protocols against network attacks. However, the traditional security protection in the IEC61850 standard is based on TCP/IP protocol, which has not addressed new efficiency, reliability and security issues. Current processing towards unified SAS platforms is proposed primarily based on network coverage. The inherent inefficiencies of the TCP/IP protocol limit the performance of the system in addressing existing problems, particularly scalability and security problems.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a naming-based secure communication method in a smart grid, which is applied to a wireless network, has secure services and can be suitable for SV and GOOSE communication which is not based on a TCP/IP protocol. The method enhances the safety performance and improves the communication efficiency, and is suitable for data sharing in a dispersed large-scale smart power grid. To create a wireless network with higher security between the bay level and the process level of the substation, the high security of the ICN is exploited based on a named communication architecture.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a naming-based secure communication method in a smart grid, which applies a wireless network and has secure services, is suitable for communication of a non-TCP/IP protocol, and transmits data from a data link layer to a presentation layer through naming, routing and caching processes of an ICN (integrated circuit network), specifically comprises the following steps:

step 1: after communication is established, a data object (NDO source) is appointed to issue the NDO to a network;

step 2: the receiver subscribes according to the NDO requirement;

and step 3: the docking system constructs a matching publishing platform;

and 4, step 4: the docking system constructs a matching subscription platform;

and 5: generating a forwarding identifier FI by using the scope identifier SI used for naming the NDO and the convergence identifier RI, and sending the FI to the NS;

step 6: according to FI, NDO is transported to NS via PSIRP.

The ICN naming has three schemes, divided by hierarchy, self-authentication, and attribute values.

In the self-certification naming scheme, one is in a format of P: L, the other is metadata, P and L represent a cryptographic hash value of a public key and respective content tags of owners, a digital signature is signed by the owners, and the metadata contains the complete public key.

The routing is based on asynchronous publishing and subscribing to establish a network in content delivery of the ICN, additional overhead is added to ensure consistency of distributed data states, and integrity and correctness of content routing depend on the infrastructure of the ICN.

The caching is to cache the content acquired in the network in the ICN, and all content providers can issue the content and can be acquired by all network nodes.

The desired NDO is commonly named by the scope identifier SI and the meeting identifier RI, both of which are described by the subscription requirements, which are then forwarded to a matching program generating a forward identifier FI.

The security service comprises an access control algorithm based on publish/subscribe, and specifically comprises the following contents:

roles, representing a set of access rights, in a one-to-many relationship with the allocation of network nodes, a node can only be granted one execution role, but one role can be allocated to multiple nodes; a node, if a publisher, will be granted an executive role based on topic, if it is a subscriber, will be granted an executive role based on a broker, and publishers of different topics will require different permissions to process data and resources;

operations, which are different instructions executed on the data source;

rights, representing permissions to perform the above operations in a protected system and data source;

the distribution relation of the authority and the execution role is many-to-many, and the system can distribute a plurality of access authorities for one role. The role of publisher is granted publication related rights and the subscriber is granted subscription related rights.

The communication of the non-TCP/IP protocol comprises SV and GOOSE communication.

Compared with the prior art, the invention has the following beneficial effects:

drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a naming-based secure communication architecture proposed by the present invention;

FIG. 2 is a proposed security communication model for SV/GOOSE;

FIG. 3 is a naming-based communication architecture;

FIG. 4 is a proposed publish/subscribe based access control;

FIG. 5 is a relationship between time delay and increase in the number of nodes;

FIG. 6 is a relationship between delay and simulation time;

FIG. 7 is a comparison of delay performance;

fig. 8 is a comparison of safety performance.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

According to the naming-based safety communication architecture in the intelligent power grid, as shown in fig. 1, a communication model with interoperability and interconnectivity between IEDs in the intelligent substation is based on an IEC61850 protocol and uses a wireless network. The sensor equipment of the substation system measures and records real-time data of voltage and current, and transmits the data to the PMU in time. The PMU is a unit that integrates all data from different sensors. The PMU then sends the compressed data to the IED via a process-level network using a name-based communication technique. The IED, upon receiving the data, begins processing the data. By processing the results, the IED can get the functions of protection control and testing the whole substation system. Additionally, the IED may also communicate with remote devices, such as remote control centers, engineer stations, human-machine interfaces, and other devices.

The naming-based secure communication architecture proposed by the present invention is described in detail below:

in a substation, sensors acquire data at the process level and transmit the sensed data to the IEDs at the bay level. In addition, communication between different IEDs also employs a name-based communication architecture.

The name-based communication architecture design of the present invention is shown in FIG. 4. The format of the physical layer conforms to a standard design. Data transfer from the data link layer to the presentation layer is through naming, routing, and caching. When a communication is created, the NDO source publishes the NDO into the network, as shown in step 1 of fig. 3. In step 2, the receiver may subscribe according to the NDO requirements. In

steps

3 and 4, the docking system builds a platform that matches publications and subscriptions. The desired NDO is commonly named by a Scope Identifier (SI) and a Rendezvous Identifier (RI), both of which are described by the subscription requirements. The identifier is then forwarded to a matching program to generate a Forward Identifier (FI). In step 5, the FI is transmitted to the NS. According to FI, NDO is transported to NS via PSIRP.

NS (NDOssource) in FIG. 3 is the NDO data source, which is the data publisher in the ICN network; scope is the matching domain of the docking system; RN (rendezvous node) is a sink node; pr (psirp router) is a router that publishes a subscription to the internet routing mode.

As for IP-based networks, information security is closely related to the security of the host. Instead, ICN provides security protection towards the information itself and achieves higher fine-grained security. The name-based communication architecture leverages the high security of ICNs.

And (4) naming. The three named schemes of ICN are divided by hierarchy, self-authentication, and attribute values. In the self-certification naming scheme, one part is in a format of P: L, and the other part is metadata. P and L represent the cryptographic hash value of the public key and the owner's respective content tag. The digital signature is signed by the owner and the metadata contains the complete public key. Designing a unique self-authenticating name is very useful for high-level security and easy for integrity checking.

And (5) caching. The content acquired in the network is cached in the ICN. This applies to content delivery under all protocols, all content providers can publish content and be available to all network nodes.

And (4) routing. In ICN content delivery, asynchronous publishing and subscription is the foundation for the network. Additional overhead is added to ensure consistency of the distributed data state. Furthermore, the integrity and correctness of content routing depends on the infrastructure of the ICN.

FIG. 2 shows a security communication model proposed by SV/GOOSE.

The publish/subscribe based access control algorithm proposed by the present invention is described in detail below:

in the smart grid, IEDs in the transformer substation control and protect the main equipment of the process layer. IEDs require different associated data according to different functions. In a name-based communication architecture, there are a number of node types that can each perform different functions. Malicious nodes may cause information leakage or network attacks, such as DDoS attacks. Thus, access control is very necessary for both IEDs and nodes in name-based communication network architectures. RBACs as a secure and efficient access control method, the concept of "roles" has been widely used, which makes it much easier to assign and manage permissions. The access control algorithm proposed by the present invention is designed on the basis of RBAC in a name-based secure communication architecture.

As a typical case, the publish-subscribe algorithm based on access control in NS is shown in fig. 4. A role represents a set of access rights. The assignment of nodes and roles is a many-to-one relationship. A node may only be granted one execution role, however one role may be assigned to multiple nodes. A node will be granted an executive role based on topic if it is a publisher and on broker if it is a subscriber. Publishers of different topics will require different permissions to process data and resources. By operation is meant different instructions to be executed on the data source, such as read, write, add, delete, and the like. Rights represent permissions to perform these operations in a protected system and data source, such as publishing and subscribing. The assignment of rights and execution roles is many-to-many. Thus, the system can assign multiple access rights to a role. The role of publisher is granted publication related rights and the subscriber is granted subscription related rights.

Aiming at communication which is not based on TCP/IP protocols such as SV and GOOSE, the invention provides the named ICN (integrated circuit network) safety method which can meet the safety requirement and can carry out high-efficiency communication. The safety method provided by the invention can meet the safety requirement and has good communication performance.

1. The design of the safety method provided by the invention can meet the safety requirement.

ICN satisfies integrity, confidentiality and non-repudiation. The use of lightweight encryption algorithms enables RBACs to achieve efficient access control while meeting the security requirements of authentication, integrity, confidentiality, and authorization.

In a TCP/IP based network, information security is closely related to the host. However, the ICN provides security protection for the information itself, achieving higher fine-grained security. The proposed naming-based communication architecture takes full advantage of the high security of ICNs. In addition to the original security measures designed in the PSIRP, RBAC and lightweight encryption algorithms are added to ensure the security of the communication based on naming. The proposed security method is designed in the form of a service, which is, in addition, composited with a secure bus and a conventional functional service.

Packet Level Authentication (PLA) technology is supported in the PSIRP, which is helpful for encrypting and signing personal data packets, and ensures the integrity and confidentiality of data and accountability of malicious publishers. Both the packets in the FN and in their destination addresses can be checked using the PLA. For an immutable data object, a self-authenticating name may be allowed in flat naming using the hash value of the object as a rendezvous point. Furthermore, the dynamic link identifier may be used for path coding to a bloom filter, which is resistant to bloom filter or logon DDoS attacks made by attackers. In addition to other security designs in PSIRP, RBAC makes it more convenient to assign and manage access control rights. The lightweight encryption algorithm ensures the safety of the data exchange process, and simultaneously occupies low communication cost, so that the communication in the smart power grid is efficient and safe.

2. The safety method provided by the invention has good communication performance.

GOOSE and SV are used for real-time communication, so latency is an important parameter in communication performance. To evaluate the performance of the proposed communication method, we simulated a lightweight encryption algorithm with NS 2. In the simulation experiment, two NSs, one client and one server, were used. The server sends 1000 packets per second encrypted with a lightweight encryption algorithm. The user's ID is included in the data packet. When clients receive packets, they decrypt the packets with their ID and key. If the decoded ID is matched with the ID of the user, the data packet is received, otherwise, the data packet is discarded. The simulation results without using the encryption algorithm were also performed under the same conditions. The client may not choose to receive all packets.

As shown in fig. 5, a transition curve of the average delay with the use of the lightweight encryption algorithm with the increase of the number of nodes and a change curve of the average delay without the use of the lightweight encryption algorithm are respectively shown. The results of fig. 5 and 6 show that the extra delay decreases with increasing number of nodes and simulation time, and even to the end, becomes very low. With the development of IEC61850, the number of IEDs in the smart grid increases, however, under this communication method, not much network delay is increased. Fig. 7 shows the fluctuation of the delay time. Adding a lightweight encryption algorithm only adds a small delay, and the average values are almost the same. The security encryption method adopted by the invention has little influence on network delay. Therefore, the safety communication method based on naming can improve safety performance at the cost of little increase of network delay. Fig. 8 shows a comparison of received packets, and the results show that the algorithm has a significant effect on security. Both spurious and invalid information is reduced.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.

Claims

1. A safe communication method based on naming in a smart power grid is characterized in that the communication method applies a wireless network, has safe services, is suitable for communication of a non-TCP/IP protocol, and transmits data from a data link layer to a presentation layer through naming, routing and caching processes of an ICN (integrated circuit network), and specifically comprises the following steps:

step 2: the receiver subscribes according to the NDO requirement;

and step 3: the docking system constructs a matching publishing platform;

and 4, step 4: the docking system constructs a matching subscription platform;

and 5: generating a forwarding identifier FI from the scope identifier SI and the rendezvous identifier RI used for naming the NDO, and sending the FI to the NDO source NS;

step 6: according to FI, NDO is transported to NS via PSIRP;

operations, which are different instructions executed on the data source;

the distribution relation between the authority and the execution role is many-to-many, the system can distribute a plurality of access authorities for one role, the role of the publisher is granted with the authority related to the publication, and the subscriber is granted with the authority related to the subscription;

the ICN naming has three schemes, which are divided by hierarchy, self-authentication and attribute values;

l, P and L represent the cipher hash value of the public key and the respective content label of the owner, the digital signature is signed by the owner and the metadata contains the complete public key;

the routing is in the content transmission of the ICN, asynchronous publishing and subscription establish a foundation for the network, additional overhead is added to ensure the consistency of the distributed data state, and the integrity and the correctness of the content routing depend on the infrastructure of the ICN;

2. The naming-based secure communication method in the smart grid according to claim 1, wherein the caching is implemented by caching the content acquired in the network in an ICN, and all content providers can publish the content and can be acquired by all network nodes.

3. The naming-based secure communication method in the smart grid according to claim 1, wherein the non-TCP/IP protocol communication includes SV and GOOSE communication.