Network Management Research Group                                J. Yan
Internet-Draft                                                  H. Zhou
Intended status: Informational                                  Y. Yang                  
Expires: April 7, 2025                                       H. Song
                                                                  Z. Tu
                                            Beijing Jiaotong University                                                                 					                                                                                                      
                                                          October 7, 2024
Document: draft-tu-nmrg-blockchain-trusted-protocol-04.txt

      A Blockchain Trusted Protocol for Intelligent Communication
                                 Network

Abstract

  This document defines a blockchain-based trusted protocol for sixth-
  generation (6G) intelligent communication network.

Status of this Memo

  This Internet-Draft is submitted in full conformance with the
  provisions of BCP 78 and BCP 79.

  Internet-Drafts are working documents of the Internet Engineering
  Task Force (IETF). Note that other groups may also distribute working
  documents as Internet-Drafts. The list of current Internet-Drafts is
  at https://datatracker.ietf.org/drafts/current/.

  Internet-Drafts are draft documents valid for a maximum of six months
  and may be updated, replaced, or obsoleted by other documents at any
  time. It is inappropriate to use Internet-Drafts as reference
  material or to cite them other than as "work in progress."

  This Internet-Draft will expire on April 7, 2025.

Copyright Notice

  Copyright (c) 2024 IETF Trust and the persons identified as the
  document authors. All rights reserved.

  This document is subject to BCP 78 and the IETF Trust's Legal
  Provisions Relating to IETF Documents (https://trustee.ietf.org/
  license-info) in effect on the date of publication of this document.
  Please review these documents carefully, as they describe your rights
  and restrictions with respect to this document. Code Components


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  extracted from this document must include Revised BSD License text as
  described in Section 4.e of the Trust Legal Provisions and are
  provided without warranty as described in the Revised BSD License.

Table of Contents

   1. Introduction...................................................2
   2. Terminology....................................................3
   3. Blockchain Trusted Protocol Architecture.......................3
   4. Blockchain Trusted Authentication Protocol.....................5
   5. Blockchain Trusted Access Control Protocol.....................6
   6. Blockchain Trusted Locator/Identifier Separation Protocol......8
   7. Blockchain Trusted Feedback Control Protocol..................10
   8. IANA Considerations...........................................12
   9. Security Considerations.......................................12
   10. References...................................................12
   Acknowledgments..................................................13
   Author's Addresses...............................................13

1. Introduction

   The sixth-generation (6G) network promotes the interconnection of
   everything and put forward higher requirements for network security.
   The existing network architecture mainly focuses on the end-to-end
   communication process and lacks the dynamic feedback to the user
   behavior. Based on the current network architecture, 6G intelligent
   communication network introduces collaborative processing unit and
   intelligent agent unit at the access gateway, and uses environment,
   media, and security knowledge base to realize dynamic control and
   closed-loop feedback of user behavior [ICN20]. Based on the 6G
   intelligent communication network architecture, this document
   proposes a blockchain-based trusted protocol for user behavior
   control. By constructing the trust link of "user identity-
   communication behavior-user reputation-security control", the
   designed trusted protocol forms the dynamic feedback and global
   control ability of the whole-process user behavior after users access
   the network.

   This document designs a blockchain trusted protocol in 6G intelligent
   communication network, including trusted authentication protocol,
   trusted access control protocol, trusted locator/identifier
   separation protocol and trusted feedback control protocol [BTP22].




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2. Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3. Blockchain Trusted Protocol Architecture

   The blockchain trusted protocol is deployed at the access gateways in
   the form of smart contracts. The smart contract in the blockchain is
   used to store the user's identity, access behavior, identification
   and other information, and security control the user's behavior
   together with the collaborative processing unit.

   Figure 1 shows the architecture of the blockchain trusted protocol,
   and the components in the architecture will be introduced separately
   next.

   o User Equipment (UE): We use UE to represent all users and devices
     in the 6G intelligent communication network, such as users,
     intelligent devices, IoT devices, etc. When a UE accesses the
     network or want to obtain the network resources, it needs to send
     a corresponding request to the access gateway. Only when the
     initiated request is approved, the UE can obtain the corresponding
     permission to access the network and resources.

   o Access Gateway (AG): The AG is responsible for receiving and
     forwarding requests sent by UE. Multiple different AGs run the
     same consensus algorithm to form a blockchain network. Besides,
     the collaborative processing module is deployed in the AG to
     response and control the user behavior.

   o Collaborative Processing Module (CPM): The CPM responds, forwards,
     and processes the requests initiated by UE. In the process of user
     behavior control, CPM is the executor of security control of UE,
     which is responsible for executing and forwarding the control
     results generated by smart contracts.

   o Smart Contract (SC): The SC is deployed in the blockchain network
     built by the AGs running the same consensus algorithm. In the
     blockchain trusted protocol architecture, the designed trusted
     protocol consists of four sub-protocols. And each sub-protocol is
     deployed in the blockchain network in the form of smart contract
     (identity authentication contract, access control contract,

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      locator/identifier separation contract, and feedback control
      contract) to security manage and control the user behavior.

  +------------------------------------------------------------------+
  |                             SMART CONTRACT                       |
  | +--------------+ +-----------+ +------------------+ +----------+ |
  | |IDENTITY      | |ACCESS     | |LOCATOR/IDENTIFIER| |FEEDBACK  | |
  | |AUTHENTICATION| |CONTROL    | |SEPARATION        | |CONTROL   | |
  | |CONTRACT      | |CONTRACT   | |CONTRACT          | |CONTRACT  | |
  | +-------^------+ +-----^-----+ +--------^---------+ +-----^----+ |
  |         |              |                |                 |      |
  +------------------------------------------------------------------+
            |              |                |                 |
            +----^---------+----------------+--------^--------+
                 |                                   |
  +-----------------------------+      +-----------------------------+
  |              |              |      |             |               |
  |  +-----------v------------+ |      | +-----------v------------+  |
  |  |COLLABORATIVE PROCESSING| |      | |COLLABORATIVE PROCESSING|  |
  |  |          UNIT          | |......| |          UNIT          |  |
  |  +------^---------^-------+ |      | +--------^--------^------+  |
  |ACCESS   |         |         |      |          |        |ACCESS   |
  |GATEWAY-1|         |         |      |          |        |GATEWAY-2|
  +-----------------------------+      +-----------------------------+
            |         |                           |        |
  +---------v--+   +--v---------+      +----------v--+  +--v---------+
  |USER        |   |USER        |      |USER         |  |USER        |
  |EQUIPMENT-1 |   |EQUIPMENT-2 |......|EQUIPMENT-n-1|  |EQUIPMENT-n |
  +------------+   +------------+      +-------------+  +------------+
          Figure 1 The architecture of blockchain trusted protocol

  o Identity Authentication Contract (IAC): The IAC is used to
    authenticate the UE identity and ensure that the identity is
    trusted. In the process of identity authentication, IAC not only
    respond to the authentication request initiated by UE and generate
    the corresponding authentication vectors, but also stores the
    authentication behavior in the blockchain to ensure the
    traceability of the user's authentication behavior.

  o Access Control Contract (ACC): The ACC generates the corresponding
    access control policy according to the access request initiated by
    the UE to ensure the action of UE is trusted. Similarly, the ACC
    records the access behavior of UE. On the one hand, it is used to
    evaluate the user reputation of the feedback control module, and
    on the other hand, it guarantees the traceability of access
    behavior of UE.




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  o Locator/Identifier Separation Contract (LISC): The LISP protocol
    is used in the 6G intelligent communication network to isolate the
    access network form the backbone network, which can improve the
    security capabilities of the network by separating the identity
    and location. Therefore, in the trusted protocol
    architecture, we use the LISC to store the mapping relationship
    between the end-identifier (EID) and the routing-locator (RLOC).

  o Feedback Control Contract (FCC): The FCC is used to evaluate the
    reputation value of the UE. This contract evaluates the UE by
    obtaining various historical behavior data (such as authentication
    behavior, access control behavior, etc.), and develops different
    levels of security control policies based on the calculated
    reputation value.

   In the following section, we describe the four trusted sub-protocols
   in detail.

4. Blockchain Trusted Authentication Protocol

   In the blockchain trusted authentication protocol, the CPM forwards
   and processes the identity authentication requests of UE, while the
   IAC stores the authentication credentials and generates the user
   authentication vector.

   Figure 2 shows the blockchain trusted authentication protocol, and
   the trusted authentication protocol can be described as the following
   steps.

   STEP 1: UE sends the UE Authentication Request (UAR) to the CPM, the
   UAR contains the identity of UE U_id and UE identification
   information I_ua.

   STEP 2: CPM invokes the interface of IAC UEAuth() to generate
   authentication vector. The input of UEAuth() contains U_id and I_ua.

   STEP 3: IAC returns the generated authentication vector (AV) to CPM.

   STEP 4: UE, CPM, and IAC interact with each other to authenticate UE
   according to the generated authentication vector.

   STEP 5: IAC stores the Identity Authentication Behavior B_ia of UE in
   the blockchain, the B_ia includes the UE identity U_id, identity
   authentication result R_ia, authentication time T_ia.


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   +---+            +---+                 +---+                    +---+
   |UE |            |CPM|                 |IAC|                    |FCC|
   +-+-+            +-+-+                 +-+-+                    +-+-+
     |1.UAR(U_id,I_ua)|                     |                        |
     +---------------->                     |                        |
     |                |2.UEAuth(U_id,I_ua)  |                        |
     |                +--------------------->                        |
     |                |3.Return AV          |                        |
     |                <---------------------+                        |
     |4.UE-CPM-IAC    |                     |                        |
     | Authentication interaction           |                        |
     <----------------+--------------------->                        |
     |                |         +-----------+----------+             |
     |                |         |5.Store               |             |
     |                |         | B_ia={U_id,R_ia,T_ia}|             |
     |                |         +-----------+----------+             |
     |                |6.Return R_ia        |                        |
     |                <---------------------+                        |
     |                |                     |7.UpdateRepIA(U_id,R_ia)|
     |                |                     +------------------------>
     |                |8.Return R_dc        |                        |
     |9.Return        <----------------------------------------------+
     | R_ia or R_dc   |                     |                        |
     <----------------+                     |                        |
     |                |                     |                        |
     +                +                     +                        +
          Figure 2 The blockchain trusted authentication protocol

   STEP 6: IAC returns the authentication result R_ia to CPM.

   STEP 7: The IAC invokes the UpdateRepIA() function of FCC to update
   the identity authentication reputation value of UE. The UpdateRepIA()
   contains U_id and R_ia of UE.

   STEP 8: If the UE is authenticated successfully, go to STEP 9.
   Otherwise, the FCC calculated the authentication reputation,
   generates and rerturns the Dynamic Control Result R_dc to CPM based
   on the evaluated reputation value.

   STEP 9: CPM forwards the R_ia or the R_dc to the UE.

5. Blockchain Trusted Access Control Protocol

  The trusted access control protocol is used to evaluate UE access
  control behavior. In the trusted access control protocol, the CPM is
  used to forward the access control requests initiated by UE, while


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  the ACC generates the access policy and stores the user access
  control behavior.

  Figure 3 represents the blockchain trusted access control protocol.

  +---+            +---+             +---+        +---+            +---+
  |UE |            |CPM|             |IAC|        |ACC|            |FCC|
  +-+-+            +-+-+             +-+-+        +-+-+            +-+-+
    |1.ACR(U_id,     |                 |            |                |
    | AI_ue,AI_nr)   |                 |            |                |
    +---------------->                 |            |                |
    |                |2.QueryIAR(U_id) |            |                |
    |                +----------------->            |                |
    |                |3.Return R_ia    |            |                |
    |                <-----------------+            |                |
    |                |4.UEAccCtr(U_id,AI_ue,AI_nr)  |                |
    |                +------------------------------>                |
    |                |                 |    +-------+-------+        |
    |                |                 |    |5.Generate R_ac|        |
    |                |                 |    +---------------+        |
    |                |                 |  +---------+-------------+  |
    |                |                 |  |6.Store                |  |
    |                |                 |  | B_ac={U_id, R_ac,T_ac}|  |
    |                |                 |  +---------+-------------+  |
    |                |7.Return R_ac    |            |                |
    |                <------------------------------+8.UpdateRepAC   |
    |                |                 |            | (U_id,R_ac)    |
    |                |                 |            +---------------->
    |                |9.Return R_dc    |            |                |
    |10.Return       <-----------------------------------------------+
    |   R_ac or R_dc |                 |            |                |
    <----------------+                 |            |                |
    |                |                 |            |                |
    +                +                 +            +                +
         Figure 3 The blockchain trusted access control protocol

  STEP 1: UE sends the Access Control Request (ACR) to CPM, ACR
  contains the UE identity U_id, access control information of UE AI_ue,
  and the access control information of the network resource AI_nr.

  STEP 2: The CPM calls the QueryIAR() function of IAC to query the
  authentication result of UE, the input of function QueryIAR()
  contains U_id.

  STEP 3: The IAC queries the authentication result of UE stored in the
  blockchain and returns the identity authentication result R_ia to the



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  CPM. If the UE is illegal, the access control result R_ac is set to 0,
  and the next step is STEP 6. Otherwise, go to STEP 4.

  STEP 4: If the identity of UE is trusted, the CPM invokes the
  UEAccCtr() function of ACC to generate the access control policy of
  UE. The input of UEAccCtr() contains U_id, AI_ue, and AI_nr.

  STEP 5: The ACC generates the access control result R_ac according to
  the AI_ue and AI_nr.

  STEP 6: Based on the generated R_ac, the ACC stores the access
  control behavior B_ac of UE in the blockchain. B_ac contains the U_id,
  R_ac, and access control time T_ac.

  STEP 7: AAC returns the access control result R_ac to CPM.

  STEP 8: The ACC invokes the UpdateRepAC() function of FCC to update
  the access control reputation value of UE. The UpdateRepAC() contains
  U_id and R_ac of UE.

  STEP 9: If the access action of UE is authorized, go to STEP 10.
  Otherwise, the FCC calculated the access control reputation,
  generates and rerturns the Dynamic Control Result R_dc to CPM based
  on the evaluated access control reputation.

  STEP 10: CPM forwards the R_ac or the R_dc to the UE.

6. Blockchain Trusted Locator/Identifier Separation Protocol

  After the UE completes the authentication and access control process,
  the EID and RLOC mapping transformation process also needs to be
  performed to improve the network security.

  The blockchain trusted locator/identifier separation protocol
  implements the mapping and conversion of EID and RLOC. In the
  blockchain trusted locator/identifier separation protocol, the CPM
  invokes the interface of the LISC to query the mapping relationship
  between EID and RLOC, and the LISC stores and records the pairing
  information of EID and RLOC to realize the separation mapping 
  between user identity and the network location.

  Figure 4 shows the blockchain trusted locator/identifier separation
  protocol, and it can be described as the follows.

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  STEP 1: UE-1 obtains the EID address (EID2) of the UE-n through the
  domain name systems or other methods, fills in each header and
  payload information, and constructs the data packet.

  +------+       +--------+          +----+   +--------+        +------+
  | UE-1 |       |AG-1/CPM|          |LISC|   |AG-2/CPM|        | UE-2 |
  |(EID1)|       |        |          |    |   |        |        |(EID2)|
  +--+---+       +---+----+          +-+--+   +---+----+        +--+---+
     |1.Obtain EID address (EID2)      |          |                |
     <------------------------------------------------------------->
     |2.Send data    |                 |          |                |
     | packet (EID1  |                 |          |                |
     | |EID2|Data)   |                 |          |                |
     +--------------->                 |          |                |
     |     +---------+---------+       |          |                |
     |     |3.Get EID1 and EID2|       |          |                |
     |     +---------+---------+       |          |                |
     |               |4.QueryRLOC      |          |                |
     |               | (EID1,EID2)     |          |                |
     |               +----------------->          |                |
     |               |5.Return         |          |                |
     |               | RLOC address    |          |                |
     |               | (RLOC1,RLOC2)   |          |                |
     |               <-----------------+          |                |
     |     +---------+----------+      |          |                |
     |     |6.Encapsulate packet|      |          |                |
     |     | (RLOC1|RLOC2|EID1  |      |          |                |
     |     | |EID2|Data)        |      |          |                |
     |     +---------+----------+      |          |                |
     |               |7.Forward new packet        |                |
     |               +-------------------------->                  |
     |               |                 | +--------+---------+      |
     |               |                 | |8.Decapsulate     |      |
     |               |                 | | packet           |      |
     |               |                 | | (EID1|EID2|Data) |      |
     |               |                 | +--------+---------+      |
     |               |                 |          |9.Forward packet|
     |               |                 |          |(EID1|EID2|Data)|
     |               |                 |          +---------------->
     |               |                 |          |                |
     +               +                 +          +                +
      Figure 4 The blockchain trusted locator/identifier separation
                                   protocol

 STEP 2: UE-1 sends the data packet, the data packets that need to
 pass through the core network will be directly forwarded to the AG-1. 
 The source and destination address in the packets are set to EID1 and
 EID2, respectively.

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 STEP 3: After receiving the packet, AG-1 obtains the IP address
 information in the packets, including the source address (EID1) and
 destination address (EID2).

 STEP 4: The CPM invokes the QueryRLOC() function of LISC to query the
 RLOC address of EID1 and EID2. The input of QueryRLOC() contains EID1
 and EID2.

 STEP 5: The LISC queries the mapping relationship between EID and
 RLOC registered in the blockchain, and returns the RLOC addresses
 (RLOC1 and RLOC2) corresponding to EID1 and EID2 to CPM respectively.

 STEP 6: After successfully obtaining the RLOC addresses corresponding
 to the two EIDs, AG-1 encapsulates the new IP header before the
 original packet. In the new IP header, the source address is set to
 RLOC1 and the destination address is set to RLOC2.

 STEP 7: Then, AG-1 searches the core routing table and forwards new
 data packets to the core network.

 STEP 8: After the data packet is forwarded through the core network
 to the AG-2 of the network egress router where the destination node
 is located, the CPM in AG-2 decapsulates the packet to obtain the
 original packet. In the original packet, the source address is EID1,
 and the destination address is EID2.

 STEP 9: By searching the local routing table, AG-2 forwards the
 original packet to UE-2.

7. Blockchain Trusted Feedback Control Protocol

 The blockchain trusted feedback control protocol is used to security
 control the behavior of UE. In the blockchain trusted feedback
 control protocol, the CPM receives the information of potential
 malicious UE detected or inferred by external modules (such as
 malicious traffic detection units, security knowledge bases), and
 calls the FCC interface to perform user historical reputation
 analysis. The FCC contract calculates the reputation value of
 potential malicious UEs, and formulates fine-grained security
 management and control strategies according to the calculated
 reputation value.





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 Figure 5 is the flowchart of the blockchain trusted feedback control
 protocol. It can be expressed in detail as the follows.

 +---------------+       +---+          +---+              +---+ +---+
 |External Module|       |CPM|          |FCC|              |IAC| |ACC|
 +-------+-------+       +-+-+          +-+-+              +-+-+ +-+-+
         |1.MI_ue=         |              |                  |     |
         |{U_id1,U_id2,...}|              |                  |     |
         +----------------->2.GetPolicy   |                  |     |
         |                 | (MI_ue)      |                  |     |
         |                 +-------------->                  |     |
         |                 |              |3.QueryHBIA(MI_ue)|     |
         |                 |              <------------------+     |
         |                 |              |4.QueryHBAC(MI_ue)|     |
         |                 |              <------------------------+
         |                 |  +-----------+-----------+      |     |
         |                 |  |5.Calculated reputation|      |     |
         |                 |  +-----------+-----------+      |     |
         |                 |      +-------+-------+          |     |
         |                 |      |6.Generate P_sc|          |     |
         |                 |      +-------+-------+          |     |
         |                 |7.Return P_sc |                  |     |
         |                 <--------------+                  |     |
         |       +---------+---------+    |                  |     |
         |       |8.Perform different|    |                  |     |
         |       | levels of control |    |                  |     |
         |       +---------+---------+    |                  |     |
         |                 |              |                  |     |
         +                 +              +                  +     +
        Figure 5 The blockchain trusted feedback control protocol

 STEP 1: CPM continuously receives the potentially malicious UE
 information MI_ue sent by the external module. MI_ue is a set of
 identities of potential malicious UE, which can be expressed as
 follows. MI_ue = {U_id1, U_id2, ...}. U_id1 and U_id2 represents
 different UE identities.

 STEP 2: After receiving potentially malicious UE information MI_ue,
 CPM invokes the GetPolicy() function of the FCC to obtain the fine-
 grained security control policies of the potential malicious UEs. The
 input of GetPolicy() is MI_ue.

 STEP 3/4: FCC calls the interface with other smart contract (IAC, ACC)
 to obtain the historical behavior of potentially malicious UE, and
 conducts the reputation value according to the UE historical behavior.
 The interface to IAC is QueryHBIA(), and to ACC is QueryHBAC(). The



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 input of QueryHBIA() and QueryHBAC() is the identity information of
 the potentially malicious user MI_ue.

 STEP 5: FCC calculated the reputation value of the potentially
 malicious UE based on the obtained historical behavior.

 STEP 6: Then, FCC generates the fine-grained security control
 policies P_sc based on the calculated reputation values.

 STEP 7: FCC returns the P_sc to CPM.

 STEP 8: CPM performs different levels of control on malicious UE
 according to the received P_sc, such as invalidation of identity
 authentication information, revocation of access control permissions,
 etc., to achieve fine-grained real-time blocking of malicious attacks
 at the access gateway of the network.

8. IANA Considerations

 This document has no IANA actions.

9. Security Considerations

 The blockchain system needs to maintain the overall security of the
 system at the levels of data content, consensus algorithms, smart
 contracts, and peer-to-peer networks through technologies such as
 cryptography and network security. Possible security problems in
 cryptography include improper key management, vulnerabilities in
 cryptographic algorithms or components. In addition, the blockchain
 trusted protocol is deployed at the access gateway of the network, so
 the identity of the access gateway needs to be trusted.

10. References

  10.1 Normative References

  [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, DOI
            10.17487/RFC2119, March 1997, <https://www.rfc-
            editor.org/info/rfc2119>.

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                    Blockchain Trusted Protocol           October   2024

  [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
            2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
            May 2017, <https://www.rfc-editor.org/info/rfc8174>.

10.2 Informative References

  [ICN20] Jiang, C., Ge, N., Kuang, L., "AI-enabled next-generation
          communication networks: Intelligent agent and AI router,
          IEEE Wireless Communications", September 2020,
          <https://ieeexplore.ieee.org/abstract/document/9210134>.

  [BTP22] Tu, Z., Zhou, H., Li, K., Song, H., Yang, Y., "A Blockchain-
          Enabled Trusted Protocol based on Whole-Process User
          Behavior in 6G Network, Security and Communication
          Networks", September 2022,
          <https://doi.org/10.1155/1970/8188977>.

Acknowledgments

  TBC

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Author's Addresses

  Jingfu Yan
  Beijing Jiaotong University
  Beijing
  Phone: <86-18810753358>
  Email: 22110030@bjtu.edu.cn

  Huachun Zhou
  Beijing Jiaotong University
  Beijing
  Phone: <86-13718168186>
  Email: hchzhou@bjtu.edu.cn

  Yuzheng Yang
  Beijing Jiaotong University
  Beijing
  Phone: <86-15802201359>
  Email: 21120151@bjtu.edu.cn

  Zhe Tu
  Beijing Jiaotong University
  Beijing
  Phone: <86-13146050755>
  Email: zhe_tu@bjtu.edu.cn

  Haoxiang Song
  Beijing Jiaotong University
  Beijing
  Phone: <86-13161229322>
  Email: 20120099@bjtu.edu.cn


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