What are the potential countermeasures or modifications to the Lightning Network protocol that could be implemented to mitigate the risk of a path probing attack, and how would these changes affect the functionality and usability of the network?
Channel Creation: The attacker would need to establish Lightning channels with multiple nodes across the network. The more nodes they are connected to, the more effective the attack. This is because the attack requires the ability to route payments through a variety of paths.
Payment Routing: The attacker would then route small payments through the network, deliberately choosing specific paths. This could be done by specifying the route when creating an HTLC (Hashed TimeLock Contract), which is the mechanism used to make payments in the Lightning Network.
Error Analysis: If a payment fails to route, the Lightning Network protocol returns an error message. Importantly, this error message includes information about where along the route the payment failed. If the payment failure was due to insufficient capacity in a channel (i.e., one of the channels along the route did not have enough balance to forward the payment), this allows the attacker to infer that the balance of that channel is less than the attempted payment amount.
Iterative Probing: By repeatedly attempting to route payments of different amounts through the same channels, and observing where and when these payments fail, the attacker can start to infer the balances of these channels. For example, if a payment of 0.01 BTC fails but a payment of 0.001 BTC succeeds, the attacker can infer that the channel balance is somewhere between those two amounts. This process can be repeated with increasingly fine granularity to learn more about the channel balance.
Balance Estimation: With enough iterations and careful analysis, the attacker may be able to estimate the balances of private channels with reasonable accuracy. This information could potentially be used for other attacks or to gain an unfair advantage in the network.
monarch / moarch
npub158…ytymk
2023-08-07 18:27:24
in reply to nevent1q…399r
Author Public Key
npub1589n5zlqgarpt7mv3g6gq0w54pnuvupnjlakr5g9nwrjv7w88mdshytymkPublished at
2023-08-07 18:27:24Event JSON
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"content": "What are the potential countermeasures or modifications to the Lightning Network protocol that could be implemented to mitigate the risk of a path probing attack, and how would these changes affect the functionality and usability of the network?\n\nChannel Creation: The attacker would need to establish Lightning channels with multiple nodes across the network. The more nodes they are connected to, the more effective the attack. This is because the attack requires the ability to route payments through a variety of paths.\n\nPayment Routing: The attacker would then route small payments through the network, deliberately choosing specific paths. This could be done by specifying the route when creating an HTLC (Hashed TimeLock Contract), which is the mechanism used to make payments in the Lightning Network.\n\nError Analysis: If a payment fails to route, the Lightning Network protocol returns an error message. Importantly, this error message includes information about where along the route the payment failed. If the payment failure was due to insufficient capacity in a channel (i.e., one of the channels along the route did not have enough balance to forward the payment), this allows the attacker to infer that the balance of that channel is less than the attempted payment amount.\n\nIterative Probing: By repeatedly attempting to route payments of different amounts through the same channels, and observing where and when these payments fail, the attacker can start to infer the balances of these channels. For example, if a payment of 0.01 BTC fails but a payment of 0.001 BTC succeeds, the attacker can infer that the channel balance is somewhere between those two amounts. This process can be repeated with increasingly fine granularity to learn more about the channel balance.\n\nBalance Estimation: With enough iterations and careful analysis, the attacker may be able to estimate the balances of private channels with reasonable accuracy. This information could potentially be used for other attacks or to gain an unfair advantage in the network.",
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