what should we learn from nakamoto's...
TRANSCRIPT
![Page 1: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/1.jpg)
ETH Zurich – Distributed Computing Group
Roger Wattenhofer
What Should We Learn From Nakamoto's Blockchain?
![Page 2: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/2.jpg)
Not Me!
![Page 3: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/3.jpg)
Blockchain: The Biggest Story in Distributed Systems Since …
![Page 4: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/4.jpg)
… the Internet?!?
![Page 5: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/5.jpg)
Cryptocurrencies
![Page 6: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/6.jpg)
![Page 7: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/7.jpg)
![Page 8: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/8.jpg)
Blockchain
![Page 9: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/9.jpg)
![Page 10: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/10.jpg)
![Page 11: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/11.jpg)
So What Is a Blockchain?
![Page 12: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/12.jpg)
![Page 13: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/13.jpg)
Distributed Systems & Cryptography(1982) (1976)
Blockchain
![Page 14: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/14.jpg)
Blockchain
![Page 15: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/15.jpg)
Transaction
4
1
5
![Page 16: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/16.jpg)
Why the Hype?
![Page 17: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/17.jpg)
Let’s Dig Deeper!
![Page 18: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/18.jpg)
Persistence
NIL
Provable
NIL
Byzantine
Fault-Tolerance
Blockchain
Immutable Crash
![Page 19: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/19.jpg)
Eventual
Strong
Speed
Blockchain
10 tx/s
10m tx/s
Throughput
Immediate
10k tx/s
![Page 20: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/20.jpg)
10 nodes
100 nodes
Scalability
Blockchain
1000 nodes
![Page 21: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/21.jpg)
Energy Consumption
![Page 22: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/22.jpg)
Hashrate � Energy/Hash ≈ 1.3 GW13 � 109 GH/s 0.1 J/GH
Proof of Work
![Page 23: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/23.jpg)
Market / Energy Value ≈ 19 GW$20k/BTC12.5 BTC $0.08/kWh
6/h
Economic Incentives
![Page 24: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/24.jpg)
Upper Bound 19 GW
Reality? Well…
Lower Bound 1,3 GW
![Page 25: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/25.jpg)
Maybe Around 5 GW
![Page 26: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/26.jpg)
10 nodes
100 nodes
Scalability
Blockchain
Country
Server Room
Energy
1000 nodes
Village
![Page 27: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/27.jpg)
What About Privacy?
![Page 28: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/28.jpg)
It’s Complicated.
![Page 29: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/29.jpg)
Operator
Open PoW
Privacy
World
![Page 30: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/30.jpg)
![Page 31: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/31.jpg)
The Seven Blockchain Dimensions
Persistence
Spee
d
Privacy
![Page 32: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/32.jpg)
The Seven Blockchain Dimensions
Persistence
Spee
d
Privacy
![Page 33: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/33.jpg)
Plenty of Research Dimensions
![Page 34: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/34.jpg)
piChain
![Page 35: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/35.jpg)
piChain: When a Blockchain Meets Paxos
= +
![Page 36: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/36.jpg)
piChain: When a Blockchain Meets Paxos
= + +
![Page 37: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/37.jpg)
Transaction
![Page 38: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/38.jpg)
Block
![Page 39: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/39.jpg)
depth
parent
![Page 40: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/40.jpg)
mediumquick
slow
![Page 41: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/41.jpg)
quick slowmedium
time
wait wait
New Transaction: Reaction Time
![Page 42: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/42.jpg)
quick medium slow
seen : either deeper or by
State Transitions
![Page 43: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/43.jpg)
Self-Healing
healthy
![Page 44: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/44.jpg)
Self-Healing
![Page 45: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/45.jpg)
committed
![Page 46: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/46.jpg)
time
ack
Truncated Paxos
*and next propose
![Page 47: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/47.jpg)
Normal Paxos
![Page 48: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/48.jpg)
A Typical Example
![Page 49: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/49.jpg)
similar essentially same goalssimple e.g., no explicit leader election
silent no msg when no tx, no heartbeatscalable O(1) msgs per node per tx
piChain vs. Raft
![Page 50: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/50.jpg)
Persistence
NIL
Provable
NIL
Byzantine
Fault-Tolerance
Blockchain
Immutable Crash
![Page 51: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/51.jpg)
Eventual
Strong
Speed
Blockchain
10 tx/s
10m tx/s
Throughput
Immediate
10k tx/s
![Page 52: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/52.jpg)
10 nodes
100 nodes
Scalability
Blockchain
Country
Server Room
Energy
1000 nodes
Village
![Page 53: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/53.jpg)
Fundamental Problem Every Node Sees Every Transaction
![Page 54: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/54.jpg)
Payment Networks
![Page 55: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/55.jpg)
Payment Network
![Page 56: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/56.jpg)
Hashed Timelocked Contract (HTLC)
![Page 57: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/57.jpg)
HTLC Example ( sells to )
1. Generate randomsecret r
2. Send hash(r) to
3. “Send money if r is known
at time 4”
4. “Send money if r is known
at time 3”
5. “Send money if r is known
at time 2”
6. “Send money if r is known
at time 1”7. Use
secret rto access
good
![Page 58: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/58.jpg)
Single Hop in Network
![Page 59: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/59.jpg)
Duplex Micropayment Channels(Example for Smart Contract)
![Page 60: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/60.jpg)
5
5
10
Duplex Micropayment Channel
![Page 61: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/61.jpg)
5
5
10
T=100
5
5
Duplex Micropayment Channel
![Page 62: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/62.jpg)
5
5
10
5
5
Blockchain
T=100
Duplex Micropayment Channel
![Page 63: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/63.jpg)
5
5
10
5
5
Blockchain
T=100
Duplex Micropayment Channel
![Page 64: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/64.jpg)
5
5
10
5
5
Blockchain
T=99
6
4
T=100
Duplex Micropayment Channel
[Decker,W,2015]
![Page 65: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/65.jpg)
5
5
10
5
5
Blockchain
T=99
6
4
T=100
Duplex Micropayment Channel
Channel must be renewed often?
![Page 66: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/66.jpg)
10
5
5
ΔT=99
6
4
ΔT=100
5
5
Blockchain
Duplex Micropayment Channel
Relative timelocks to keep channel alive forever!
But only 99 transactions?
![Page 67: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/67.jpg)
ΔT=20
ΔT=19
ΔT=20
ΔT=19
ΔT=20
ΔT=19
ΔT=20
ΔT=19
ΔT=19
ΔT=20
ΔT=20
ΔT=19
ΔT=20
ΔT=19
Duplex Micropayment Channel
[Decker,W,2015]
![Page 68: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/68.jpg)
5
5
10
5
5
Blockchain
T=99
4
5
T=100
HTLC Revisited
1can be spent
by blue with secret r orby green after 3 days
4. “Send money if r is known
at time 3”
![Page 69: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/69.jpg)
5
5
10
5
5
Blockchain
T=99
4
5
T=100
HTLC Revisited
1
4
6
T=98
can be spentby blue with secret r orby green after 3 days
4. Send money if r is known at time 3
![Page 70: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/70.jpg)
Solved?
![Page 71: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/71.jpg)
Still Too Many Channels!?
![Page 72: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/72.jpg)
… needs two transactions on blockchain
… has locked-in funds by both parties
Each and Every Channel
![Page 73: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/73.jpg)
… needs two transactions on blockchain
200-800M channels only
… has locked-in funds by both parties
all my bitcoins are locked-in… sad.
Each and Every Channel
![Page 74: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/74.jpg)
Blockchain Space
so far 4 signatures for every channel
Blockchain Space ~ Number of Signatures
SettlementFunding
![Page 75: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/75.jpg)
Locked Funds
?
?
A node wants to make connections…
Where does it lock the funds?
?
?
![Page 76: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/76.jpg)
5
5
5
5
T=99
6
4
T=100
5
5
5
T=100
T=99
...
...
...
...
...
...
...
...
...
Channel funding layer Payment network layer
Multi Layer Networks
[Bur
cher
t, De
cker
, W 2
017]
![Page 77: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/77.jpg)
5
5
5
5
5
ΔT=100
ΔT=99
...
...
...
...
...
...
...
...
...
Multi Layer Networks
...
[Bur
cher
t, De
cker
, W 2
017]
![Page 78: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/78.jpg)
5
5
5
5
5
...
...
...
...
...
...
...
...
...
Multi Layer Networks
...
5
5
5
5
5
SettlementTransaction
ΔT=100
ΔT=99
[Bur
cher
t, De
cker
, W 2
017]
![Page 79: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/79.jpg)
5
5
5
5
5
...
...
...
...
...
...
...
...
...
Multi Layer Networks
...
5
5
5
5
5
SettlementTransaction Actual channels never reach the
blockchain!
ΔT=100
ΔT=99
[Bur
cher
t, De
cker
, W 2
017]
![Page 80: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/80.jpg)
5
5
5
5
5
5
5
5
5
5
2 signatures per user
independent of channels
4 signatures per channel
Blockchain Transactions
old
new
![Page 81: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/81.jpg)
Are We Finally Done?!?
![Page 82: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/82.jpg)
Yes, unless you have Bitcoin Cash…
![Page 83: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/83.jpg)
Persistence
NIL
Provable
NIL
Byzantine
Fault-Tolerance
Blockchain
Immutable Crash
![Page 84: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/84.jpg)
Eventual
Strong
Speed
Blockchain
10 tx/s
10m tx/s
Throughput
Immediate
10k tx/s
![Page 85: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/85.jpg)
10 nodes
100 nodes
Scalability
Blockchain
Country
Server Room
Energy
1000 nodes
Village
![Page 86: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/86.jpg)
Summary
![Page 87: What Should We Learn From Nakamoto's Blockchain?opodis2017.campus.ciencias.ulisboa.pt/presentations/Keynote1.pdf · 10. 5. 5. ΔT=99. 6. 4. ΔT=100. 5. 5. Blockchain. Duplex Micropayment](https://reader035.vdocuments.us/reader035/viewer/2022070802/5f02c94c7e708231d40600f1/html5/thumbnails/87.jpg)
Thank You!Questions & Comments?
www.disco.ethz.ch
Thanks to my co-authorsConrad BurchertChristian Decker