How to Hack Blockchain Systems Parinya Ekparinya Vincent Gramoli - - PowerPoint PPT Presentation

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How to Hack Blockchain Systems Parinya Ekparinya Vincent Gramoli - - PowerPoint PPT Presentation

Aug 16, 2022 213 likes •634 views

How to Hack Blockchain Systems Parinya Ekparinya Vincent Gramoli Guillaume Jourjon The University of Sydney Page 1 Blockchain Block #41 Block #42 Block #43 Block #44 Proof: Proof: Proof: Proof: 0xd00d1e 0xc0ffee 0xf00baa

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How to Hack Blockchain Systems

Parinya Ekparinya Vincent Gramoli Guillaume Jourjon

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Block #42 Proof: 0xc0ffee… Parent Proof: 0xd00d1e… Block #44 Proof: 0xfabfab… Parent Proof: 0xf00baa… TX: Mallory -> Bob Block #43 Proof: 0xf00baa… Parent Proof: 0xc0ffee… TX: Ted -> Alice TX: Mallory -> Alice Block #41 Proof: 0xd00d1e… Parent Proof: 0xf00baa…

Blockchain

TX: Alice -> Bob

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Block #42 Proof: 0xc0ffee… Parent Proof: 0xd00d1e… Block #44 Proof: 0xfabfab… Parent Proof: 0xf00baa… TX: Mallory -> Bob Block #43 Proof: 0xf00baa… Parent Proof: 0xc0ffee… TX: Ted -> Alice TX: Mallory -> Alice Block #41 Proof: 0xd00d1e… Parent Proof: 0xf00baa…

Blockchain

TX: Alice -> Bob

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$ 10

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$ 10

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$ 10 $ 10

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$ 10 $ 10

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$ 10 $ 10

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$ 10 $ 10

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$ 10 $ 10

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$ 10

What da h…

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Q: is it possible to double spend on Ethereum with network attacks?

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Approaches to study … – Goals:

  • 1. How the blockchain system decide a block?
  • 2. How the blockchain system resolve fork?
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Approaches to study … – Goals:

  • 1. How the blockchain system decide a block?
  • 2. How the blockchain system resolve fork?

– Reading the documentation

– Scattered and un-organised information: website, wiki, github, issue tracker, yellow paper , etc. – Lack of necessary information – Intention ≠ Actual implementation

– Reading the code !! – Running it for real because the devil is in the detail …

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Decided Blocks and Committed Transactions in PoW/Ethereum

– Given a blockchain with parameter k, a block at index i is decided when the chain depth reaches i+k – A transaction is committed if it belongs to a decided block

Ekparinya et al, "Impact of Man-in-the-middle Attacks on Ethereum"

1 i i+1 i+k i+k-1 Decided block Transaction Undecided block

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Expected Branch Selection in PoW/Ethereum: GHOST

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Expected Branch Selection in PoW/Ethereum: GHOST

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Actual Branch Selection in PoW/Ethereum: Highest total difficulty

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Actual Branch Selection in PoW/Ethereum: Highest total difficulty

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Example 1: Man-in-the-middle Attack against PoW

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Example 1: Man-in-the-middle Attack against PoW

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Example 1: Man-in-the-middle Attack against PoW

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Example 1: Man-in-the-middle Attack against PoW

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Example 1: Man-in-the-middle Attack against PoW

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Decided Blocks and Committed Transactions in AuRa PoA/Ethereum

– A decision requires strictly more than half, only one partition may decide blocks Can decide a block

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Branch Selection in AuRa PoA/Ethereum : Longest branch

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Branch Selection in AuRa PoA/Ethereum : Longest branch

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Example 2: The Cloning Attack against PoA

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Example 2: The Cloning Attack against PoA

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Example 2: The Cloning Attack against PoA

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Example 2: The Cloning Attack against PoA

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Example 2: The Cloning Attack against PoA

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The requirements for the experiments

– Control over computing resources – Network control and isolation – Highly automated – Robust data collection ➢ OpenStack Private Cloud ➢ Virtual switches, Virtual routers (Quagga) and VLAN ➢ OpenStack API and Ethereum API ➢ Elasticsearch

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Testbed Provisioning

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Testbed Provisioning

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Testbed Provisioning

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Testbed Provisioning

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Time for Discussions !!