Use cases of Blockchain: Application and Interworking
draft-yang-usecase-din-00

Abstract

The purpose of this document is to analyze several important use cases based on blockchain, including: blockchain based PKI for security connection, blockchain as a service, interworking cross blockchain (exchange data and contracts cross chains).Through case analysis, important scenarios and specific requirements are listed. Related solutions are also provided for easy understanding.

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Table of Contents

• 1. Introduction
• 2. Requirements Language
• 3. Terminology and Abbreviations
• 4. Use case 1: Secure connection between devices using blockchain based PKI
• 4.1. Centralized connected model
• 4.2. Peer-to-peer connection model
• 4.3. Summary
• 5. Use case 2: Blockchain as a Service
• 6. Use case 3: Blockchain Interworking
• 7. IANA Considerations
• 8. Security Considerations
• 9. Normative References
• Author's Address

1. Introduction

Blockchain helps to establish cross industry mutual trust and cooperation, and can provide the transmission of value and trust on top of current information network (i.e., Internet). The following industries are studying the application of block chains: government, commerce, industry, finance, insurance, medical, education, communication, culture and art etc.

Blockchain can play the following role in a company:

• Promoting internal cooperation and optimizing the existing process, thus improves the production efficiency.
• Strengthen cooperation inside the industry, to enhance the whole industry. Take telecom for example, interoperability and roaming of inter-operations.
• Improving the cooperation of eco-system players, to improve the overall benefit. Take telecom for example, blockchain shall be able to link vendors, operators,end users information and activities together to build up trust.
• Expand business to the whole industry, the whole society and the world, to form new industries and new business models

In this document several important use cases based on blockchain are analyzed, including: blockchain based PKI system, blockchain as a service, interworking cross blockchain (exchange data and contracts cross chains). For easy understanding, related solutions are also provided.

2. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

3. Terminology and Abbreviations

The terminology and abbreviations used in this document are defined in this section.

• HeNB: Home eNodeB, An eNodeB is an element of a Radio Access Network,it performs the same functionality of an eNodeB, but is deployed for indoor premises or public hotspots, using the end-uer's home Internet to access Operators network.
• MNO: Mobile Network Operator
• SeGW: Security Gateway, an edge device that is Deployment on the boundary of an Operator's network, to connect HeNB device remotely.

4. Use case 1: Secure connection between devices using blockchain based PKI

Digital certificates are widely used to negotiate secure channels between devices and to establish secure connections as defined in RFC 5280. Accoding to communication model, there are two typical sceniaros: multiple devices are connected to the same centralized node (such as HeNBs connected to a MNO's SeGW), peer to peer connection (such as IoT devices).

4.1. Centralized connected model

Take the HeNB scenario for example, HeNB is a device that is installed in the office/home where the radio signal is weak or not covered by MNOs, to provide mobile network services (such as voice call, messaging). HeNB access MNO's network via local user's Internet access (LAN). Security solution is needed to authorize the HeNB device and to secure the connection between HeNB device and MNO network border (SeGW), as shown in Figure 1.

                                                              
                _________                     __________      
+------+     __(         )_           +------(          )_    
| HeNB |   _(   Internet   )__        |      |    MNO     )__ 
|      +--(                   )-------+ SeGW |   network     )
+------+  (___________________)       +------(_______________)
  Cert(===============================)Cert                   
of CA1       Secure Connection         of CA1                 
         
       		

Figure 1

Because not every SeGW uses the certificates issued by the same CA, HeNB needs to configure the certificate of the SeGW that it is connected to. The certificate shall provide two functions: authentication of HeNB devices, and the establishment of secure end to end communication channels in an unsafe Internet network.For this reason, the manufacture can not preinstall any certificate for HeNB; When deploying the HeNB, the workers need to manually provision the certificate for the HeNB. In this way, two problems occurs: first, is low efficiency and error-pronel second, the risk of certificate leakage. Besides, reconfiguration are needed each time when the certificate is expired of withdrawn.

The solution is:

• Establish a consortium blockchain, which is used to verify and store certificates. Manufacturers and MNOs join the chain as nodes, which are responsible for certificate verification and storage.
• A self-signed certificate for each HeNB device is generated by the manufacture when it is produced.
• This certificate shall be sent to blockchain nodes to be verified.
• The certificate is verified by the verification node.
• The certificate is recorded into the blockchain if it achieves consensus.
• At the time HeNB is installed and power on, it's certificate will be used to establish connection to MNO's SeGW.
• The SeGW interacts with the MNO's blockchain node to verify the certification.
• If success, the secured connection between SeGW and HeNB shall be installed automatically.

Note: Although in this case we uses the operator's HeNB scenario, this solution can be used for other similar connection models.

4.2. Peer-to-peer connection model

Take IoT scenario for example. Currently, our IoT devices always talk to each other via the network side server (such as IoT application server). For privacy and security consideration, we may need our IoT devices that produced by different venders to talk with each other directly in security. But we can not assume that all these devices be preinstalled with the certificates issued by the same CA. The current regular solution is to introduce a bridge-CA. the question is that, firstly, the bridge is not efficiency and lack extensiblity.

The solution is:

• Establish a consortium blockchain, which is used to verify and store certificates. CAs join the chain as nodes, which are responsible for certificate verification and storage.
• When a CA issue certificate for each device, the certificate shall be sent to blockchain nodes to be verified.
• The certificate is verified by the verification node.
• The certificate is recorded into the blockchain if it achieves consensus.
• At the time devices need direct secure connection, they will lookup their CA's node for centification verificaton.
• If success, the secured connection between devices directly and automatically.

4.3. Summary

The advantages of usging blockchain based PKI includes:

• High reliability and performance: each node holds a copy of consistent certificate data, supports multiple duplicates and parallel queries, and better data consistency.
• Low cost: automatic operation of block chain system, low maintenance cost; no payment needed for self signed certificate.

5. Use case 2: Blockchain as a Service

The value of blockchain in building a system of trust and collaboration has been proved by the industry, and more and more enterprises and industries are applying the blockchain. However, not all enterprises are willing to establish and operate their own blockchain system. Therefore, providing blockchain as a service contributes to the rapid popularization of blockchain.

The main requirements for blockchain-as-a-service may include:

• General proposed data format to support different applications, for storage/verification/resolve
• Define flexible, extensible interfaces/APIs that is easy for programming
• Enhanced performance for future proof

6. Use case 3: Blockchain Interworking

According to the current situation of the vertical development of the blockchain infrastructures and applications, the cross-chain interworking shall be a very important demand in the future Cross chain interoperability involves not only data, but also smart contracts, security and other aspects

Two solutions for blockchain interworking:

• API/Interface invocation based, using interworking gateway.
• Build a "meta blockchain" to coordinate interworking blockchains

7. IANA Considerations

This memo includes no request to IANA.

8. Security Considerations

TBA

9. Normative References

Author's Address