Hyperledger Fabric v2.0 Alpha - FabToken Overview, Hands-On Lab

1. Hyperledger Fabric – v2.0
Alpha
FabToken Overview & Hands-On
Lab
Hyperledger Korea User Group

2. 2

3. 엔터프라이즈 블록체인 - Token
3
• R3 Corda – Tokens SDK
• JP Morgan Quorum – JPM Coin
- https://www.jpmorgan.com/global/news/digital-coin-payments
• Hyperledger Fabric v2 – FabToken
- Token Management Enablement in Hyperledger Fabric
 http://bit.ly/2KvVKb4
- Token (base support) - Support Issue, Transfer, and Redeem Token Operations
 https://jira.hyperledger.org/browse/FAB-11144
- Using FabToken
 https://hyperledger-fabric.readthedocs.io/en/latest/token/FabToken.html

4. FabToken
4
• Hyperledger Fabric v2.0
- https://github.com/hyperledger/fabric/tree/master/token
• Token Management System
• Unspent Transaction Output (UTXO) 모델
• 합의, 검증을 위해 Orderer, Peer 사용
• 토큰 생성, 관리를 위해 체인코드를 사용하지 않음.(Endorsement Policy X)
• s송/수신자 식별 – MSP
• Token Lifecycle: Issue, Transfer, Redeem, List

5. Unspent Transaction Output (UTXO)
5출처 - https://codechain.readthedocs.io/en/latest/transactions.html

6. Hyperledger Fabric – UTXO
6
• 패브릭에서는 상태(State)는 Key-Value 형태로 저장
Key : Namespace + TokenPrefix + Owner + TransactionId + Index
Value: Quantity
• Unspent Transaction(Output)은 Ledger(State DB)에 저장되고
Spent Transaction(Input)은 Ledger(State DB)에서 삭제됨.

7. Hyperledger Fabric – UTXO Transaction
7
Org1
100
IN OUT
Org1
100
IN OUT
Org1
50
Org2
50
Tx #1 Tx #2
{Org1-Tx#1, 100}
Issue to Org1(100) Transfer Org1 to Org2(50)
{Org1-Tx#2, 50}
{Org2-Tx#2-1, 50}
{Org1-Tx#1, 100}
Redeem from Org2(20)
Tx #3
Org2
50
IN OUT
Org2
30
20
{Org1-Tx#1, 100}
{Org1-Tx#2, 50}
{Org2-Tx#2-1, 50}
{Org2-Tx#3, 30}
{Tx#3-1, 20}

8. Token Transaction Flow
8
Client Prover Peer
① Request
(Issue,Transfer,Redeem)
② TokenTransaction
③ Envelope
④ Block
Peer
(Committer)
Validation(VSCC)
Commit(Simulation)

9. Prover Peer
9
• 연산(computation) 실행…
• 비밀정보 유지…
• 트랜잭션 상태, 토큰 몰록 질의 대응…
• 토큰 발행 및 전송 시 검증
- TokenTransaction 생성

10. Token Lifecycle
10
• Issue
• List
• Transfer
• Reedem

11. Token Lifecycle – issue (계속)
11
• 채널 내 허가 받은 MSP에 의해 토큰 생성
- IssuingPolicy : v2.0 alpha 버전에서는 ANY로 설정됨.
• 속성
- Owner: MSP
- Type: 토큰 이름. 예> FabCoin, HLKUGCoin,…
- Quantity

12. Token Lifecycle - issue
12
• SDK (node.js)
const tokenclient = client.newTokenClient(mychannel);
const txId = client.newTransactionID();
const param = {
owner: user1.getIdentity().serialize(),
type: 'USD',
quantity: '500',
};
const issueRequest = {
params: [param],
txId: txId,
};
const result = await tokenClient.issue(issueRequest);

13. Token Lifecycle – list (계속)
13
• Unspent 토큰에 대해 질의
- 권한: 토큰 소유자 MSP
• 질의 결과 값
- TokenID: 트랜잭션 ID, 인덱스
- Type: 토큰 이름. 예> FabCoin, HLKUGCoin,…
- Quantity

14. Token Lifecycle - list
14
• SDK (node.js)
const user1Tokenclient = client1.newTokenClient(mychannel);
const mytokens = await user1TokenClient.list();
for (const token of tokens) {
// get token.id, token.type, and token.quantity
// token.id will be used for transfer and redeem
}

15. Token Lifecycle – transfer (계속)
15
• 토크 전달, 토큰 소비
- 권한: 토큰 ID의 소유자(MSP)
• 파라미터
- Token ID: 토큰 ID
- Quantity
- Recipient: 수신자(MSP)

16. Token Lifecycle - transfer
16
• SDK (node.js)
const txId = client1.newTransactionID();
const param = {
owner: user2.getIdentity().serialize(),
quantity: '300',
};
// create the request for transfer
const transferRequest = {
tokenIds: [tokenid1],
params: [param],
txId: txId,
};
const mytokens = await user1TokenClient.transfer(transferRequest);

17. Token Lifecycle – redeem (계속)
17
• 비즈니스 네트워크(채널)에서 asset(token) 제거
- 권한: 토큰 ID의 소유자(MSP)
- Reedm된 토큰은 transfer/change되지 않음.
• 파라미터
- Token ID: 토큰 ID
- Quantity

18. Token Lifecycle - redeem
18
• SDK (node.js)
const user2Tokenclient = client2.newTokenClient(mychannel);
const txId = client2.newTransactionID();
const param = {
quantity: '100',
};
const redeemRequest = {
tokenIds: [tokenid2],
params: [param],
txId: txId,
};
const result = await user2TokenClient.redeem(redeemRequest);

19. 핸즈온 랩 자료
19
http://bit.ly/hlkug_handson190
6

20. BYFN(Building Your First Network)
20
Peer Peer
Peer PeerOrderer
Org1
Org2peer0.org1.example.com
peer1.org1.example.com
peer0.org2.example.comorderer.example.com
fabric_byfn
peer1.org2.example.com

21. Future features
21
• non-fungible tokens
- Non fungible tokens cannot be merged or divided.
• chaincode interoperability
- allows tokens to be issued, transferred, and redeemed by chaincode

22. 22
감사합니다.