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Information Propagation in the Bitcoin Network
Christian Decker
ETH Zurich – Distributed Computing Group – www.disco.ethz.ch
Information Propagation in the Bitcoin Network Christian Decker - - PowerPoint PPT Presentation
Information Propagation in the Bitcoin Network Christian Decker - - PowerPoint PPT Presentation
Information Propagation in the Bitcoin Network Christian Decker ETH Zurich Distributed Computing Group www.disco.ethz.ch What is Bitcoin? What is Bitcoin? + What is Bitcoin? = + Whats it worth? USD / Bitcoin exchange price 300
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What is Bitcoin?
+
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What is Bitcoin?
+ =
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What’s it worth?
O c t 2 1 F e b 2 1 1 J u n 2 1 1 O c t 2 1 1 F e b 2 1 2 J u n 2 1 2 O c t 2 1 2 F e b 2 1 3 J u n 2 1 3 50 100 150 200 250 300 Price [USD]
USD / Bitcoin exchange price
150$/BTC
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What’s it worth?
O c t 2 1 F e b 2 1 1 J u n 2 1 1 O c t 2 1 1 F e b 2 1 2 J u n 2 1 2 O c t 2 1 2 F e b 2 1 3 J u n 2 1 3 50 100 150 200 250 300 Price [USD]
USD / Bitcoin exchange price
150$/BTC
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What’s it worth?
O c t 2 1 F e b 2 1 1 J u n 2 1 1 O c t 2 1 1 F e b 2 1 2 J u n 2 1 2 O c t 2 1 2 F e b 2 1 3 J u n 2 1 3 50 100 150 200 250 300 Price [USD]
USD / Bitcoin exchange price
150$/BTC
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What’s it worth?
O c t 2 1 F e b 2 1 1 J u n 2 1 1 O c t 2 1 1 F e b 2 1 2 J u n 2 1 2 O c t 2 1 2 F e b 2 1 3 J u n 2 1 3 50 100 150 200 250 300 Price [USD]
USD / Bitcoin exchange price
150$/BTC
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Why so popular?
- Global
- Fast
- Irreversible
- No intermediary
- Anonymous
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Bitcoin Basics
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Bitcoin basics
✠
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Bitcoin basics
TX TX’ TX”
✠
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Bitcoin basics
TX TX’ TX”
✠
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Bitcoin basics
✠
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Bitcoin basics
✠
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Our Results
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Propagation speed
10 20 30 40 50 60 Time since first observation [s] 0.00 0.02 0.04 0.06 0.08 0.10 0.12 PDF
Block propagation
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Propagation speed
10 20 30 40 50 60 Time since first observation [s] 0.00 0.02 0.04 0.06 0.08 0.10 0.12 PDF
Block propagation
50th perc.
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Propagation speed
10 20 30 40 50 60 Time since first observation [s] 0.00 0.02 0.04 0.06 0.08 0.10 0.12 PDF
Block propagation
50th perc. 95th perc.
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Propagation speed
10 20 30 40 50 60 Time since first observation [s] 0.00 0.02 0.04 0.06 0.08 0.10 0.12 PDF
Block propagation
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Information eclipsing
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Information eclipsing
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Information eclipsing
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Information eclipsing
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Blockchain Basics
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The Blockchain
Time
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The Blockchain
Time
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The Blockchain
Time
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The Blockchain
Time
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Our Results
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Blockchain Forks
180000 182000 184000 186000 188000 190000 Blockchain Height 2 4 6 8 10 12 Forks
Blockchain forks
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Blockchain Forks
180000 182000 184000 186000 188000 190000 Blockchain Height 2 4 6 8 10 12 Forks
Blockchain forks
1.69%
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Blockchain Forks: Model
Probability of finding a block: Pb = Pr[Xb < t + 1|Xb ≥ t] ≈ 1/600
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Blockchain Forks: Model
Probability of finding a block: Pb = Pr[Xb < t + 1|Xb ≥ t] ≈ 1/600 Part of the network that may fork: f (t) = fraction of network knowing block at time t
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Blockchain Forks: Model
Probability of finding a block: Pb = Pr[Xb < t + 1|Xb ≥ t] ≈ 1/600 Part of the network that may fork: f (t) = fraction of network knowing block at time t Probability of a blockchain fork Pf = 1 − (1 − Pb)
∞
0 (1−f (t))dt
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Blockchain Forks: Validating our Model
Pb = 1/633.68 ¯ F = ∞ (1 − f (t))dt = 11.37 Pf = 1 − (1 − Pb)
¯ F = 1.78%
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Pushing the protocol to its limits
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Pushing the protocol to its limits
Node A Node B block verification inv g e t d a t a block
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Pushing the protocol to its limits
Node A Node B block diff verification inv getdata block
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Pushing the protocol to its limits
Node A Node B block diff verification inv getdata inv getdata block
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Did it work?
180000 182000 184000 186000 188000 190000 Blockchain Height 2 4 6 8 10 12 Forks
Blockchain forks
1.69%
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Did it work?
200000 202000 204000 206000 208000 210000 Blockchain Height 2 4 6 8 10 12 Forks
Blockchain forks (influenced)
1.69% 0.78%
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What does this mean?
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What does this mean?
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Conclusion
10 20 30 40 50 60 Time since first observation [s] 0.00 0.02 0.04 0.06 0.08 0.10 0.12 PDF
Block propagation
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Conclusion
10 20 30 40 50 60 Time since first observation [s] 0.00 0.02 0.04 0.06 0.08 0.10 0.12 PDF
Block propagation
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Conclusion
10 20 30 40 50 60 Time since first observation [s] 0.00 0.02 0.04 0.06 0.08 0.10 0.12 PDF
Block propagation
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Thank you, questions?
Authors: Christian Decker Roger Wattenhofer
ETH Zurich – Distributed Computing Group – www.disco.ethz.ch