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CryBlock 2019
G-IOTA: Fair and Confidence Aware Tangle
Authors: Gewu BU, Önder GURCAN (CEA LIST) and Maria POTOP-BUTUCARU
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Fairness
CryBlock 2019
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Gewu BU
CryBlock 2019 G-IOTA: Fair and Confidence Aware Tangle Authors: Gewu - - PowerPoint PPT Presentation
CryBlock 2019 G-IOTA: Fair and Confidence Aware Tangle Authors: Gewu - - PowerPoint PPT Presentation
CryBlock 2019 G-IOTA: Fair and Confidence Aware Tangle Authors: Gewu BU, nder GURCAN (CEA LIST) and Maria POTOP-BUTUCARU 1 Fairness ? CryBlock 2019 2 Gewu BU IOTA CryBlock 2019 3 Gewu BU IOTA Bitcoin Miners CryBlock 2019 4 Gewu BU
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IOTA
Gewu BU
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Miners IOTA Bitcoin
Gewu BU
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Users IOTA Bitcoin Miners
Gewu BU
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IOTA-Tangle: a Transactions-DAG
(DAG: Directed acyclic graph)
[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Gewu BU
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
IOTA-Tangle: a Transactions-DAG
(DAG: Directed acyclic graph)
[1]
Gewu BU
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
IOTA-Tangle: a Transactions-DAG
(DAG: Directed acyclic graph)
[1]
Gewu BU
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tips tips
[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
IOTA-Tangle: a Transactions-DAG
(DAG: Directed acyclic graph)
[1]
Gewu BU
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Tips selection Algorithm
(TSA) T2 T1 T3 T4 T5
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Gewu BU
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Level of Confidence
T5 T2 T1 T3 T4 Tb Ta Tc
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Gewu BU
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T5
TSA = Uniform
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Level of Confidence
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T5 T2 T1 T3 T4 Tb Ta Tc 25% 100% 75% 25% 25% 25% 25%
[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Gewu BU
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Conflicting Transactions
T2 T1 T3 T5
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Ta Tb
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
75% 50%
Gewu BU
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T2 T1 T3 T5 Ta Tb
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Conflicting Transactions
[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
75% 50%
Gewu BU
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
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Weighted Random Walk TSA
[1]
Fairness
Gewu BU
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4 2 2 1 Cumulative weight
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
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Weighted Random Walk TSA
[1]
Gewu BU
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10 10 8 4 6 3 7 2 5 2 1
Weighted Random Walk TSA
3 Cumulative weight
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
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[1]
Gewu BU
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10 10 8 4 6 3 7 2 5 2 1
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
CryBlock 2019
[1]
Weighted Random Walk TSA
Gewu BU
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10 10 8 4 6 3 7 2 5 2 1
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Weighted Random Walk TSA
Gewu BU
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10 10 8 4 6 3 7 2 5 2 1
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Weighted Random Walk TSA
Gewu BU
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10 10 8 4 6 3 7 2 5 2 1
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Weighted Random Walk TSA
Gewu BU
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10 10 8 4 6 3 7 2 5 2 1
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Weighted Random Walk TSA
Gewu BU
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10 10 8 4 6 3 7 2 5 2 1
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
Weighted Random Walk TSA
Gewu BU
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To the next hop having the maximal CW
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Weighted Random Walk -> Unweighted Random Walk
Rapidly Decaying parameter α
[1]
- > Infinity
α
- > 0
α
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org
Gewu BU
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Splitting attack
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[1] Popov S. The tangle[J]. cit. on, 2016: 131.https://www.iota.org [1]
cumulative weight: 537 cumulative weight: 541
X
Attacker conflicting transactions Conflicting transactions
Gewu BU
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Fairness issue
An example of tangle with a relatively high α = 0.7. Many tips are left behind.
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Gewu BU
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Fairness issue
An example of tangle with a relatively high α = 0.7. Many tips are left behind.
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Gewu BU
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Left-behind tips: tips who have not been approved for a time D_tips. Left-behind transactions: non-tips transactions who have not been confirmed for a time D_tran.
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Fairness issue
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Gewu BU
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The confidence of a transaction is at least equal to the maximal confidence among all its son transactions. Ta Tb Td Tc C = 78% C = 60% C = 40% C = 78%
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Observation
Gewu BU
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G-IOTA
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Gewu BU
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future tips
G-IOTA
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Gewu BU
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IOTA G-IOTA
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Gewu BU
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IOTA G-IOTA vs
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0.75 0.50 0.25 1 100 75 50 25
Gewu BU
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Mutual Supervision Mechanism
1) What if a speculative user always verifies a third tips, a non-left- behind tips, to pretend that it works hard for helping the others? 2) What if a lazy user only chooses old conformed transactions to verify and pretends his transaction has been left-left-behind and waits others saving his transaction? Sender neighbour Sender neighbour Updating
check check
Rejecting / reporting
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Gewu BU
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Benefits of choosing the 3th tips
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Gewu BU
Game theory
G-IOTA has at lest the same security level than IOTA
Formal proof
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IOTA
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Gewu BU
CryBlock 2019