Why double spend attacks on Lightning are not possible

Margherita Favaretto, a student working on remediation protocol for Lightning Network double-spend attacks asked for feedback for a proposed solution to double spend attacks using a “trusted remediation” gossip protocol.

ZmnSCPxj pointed out that double spend attacks are not possible on the Lightning Network unless both parties involved in the channel agree to it, which is not likely, first because the man at the other end of the channel will lose money. Secondly even if the other end of the channel is irrational enough to help the other guy double spend, they will still ask for an invoice and give the money using “existing invoice-payment mechanisms.” ZmnSCPxj added:

If the problem you are trying to solve, is the inadvertent publication of revoked commitment transactions, then the correct solution is not to have revocable transactions in the first place, i.e. eltoo. While it can be argued that it would take time for needed features of eltoo to appear on the blockchain layer (SIGHASH_NOINPUT_UNSAFE), it would also take time to implement “trusted remediation”, by which time the problem could be solved by switching over to eltoo.

Bitcoin Encrypted Communication (BIP151) Overhaul

On of the pros of Bitcoin since its birth is that it’s a public ledger, anyone is allowed to send and receive payments and data on the Blockchain. However, Bitcoin’s network does not provide a way of encrypting communication between nodes, which allows manipulation of data, mass surveillance and analysis of its users.

Although encrypted communication is currently a possibility with VPNs, TOR or other mechanisms, it is not easy for the average user to setup such a connection. There is BIP draft called BIP151 that aims to add encrypted communication to Bitcoin’s network and which currently seems implemented only by Armory.

Jonas Schnelli presented an overhauled version for BIP 151 with some major changes:

Guiding Transaction Fees Towards a more Censorship Resistant Outcome

This is summary for a submission by Ruben Somsen on bitcoin-dev on censorship resistant transactions.


Bitcoin transactions with light client wallets involve addition of transaction fees as incentive for miners to include the transaction to the blockchain through the process of mining. This creates a win-win situation.

First, without any specific conditions, miners get paid the fees provided the transaction gets included in a valid chain with the most proof-of-work.

Secondly, the user enjoys the benefit of his transaction being added to the blockchain. The fees also ensure the security of transaction on the network as miners cannot ignore the transactions or other miners will process it because it has a reward attached.

For the full node Bitcoin Core however, conditions for adding transactions to the blockchain are more specific, one of which is that transactions can only be added to a block with a block height that is one higher than the last.