bitcoin-dev

A Free-Relay Attack Exploiting RBF Rule #6

A Free-Relay Attack Exploiting RBF Rule #6

Original Postby Peter Todd

Posted on: March 28, 2024 19:47 UTC

The email explores the concept of re-using proof-of-UTXO within the Bitcoin network, highlighting a theoretical scenario to examine the implications on bandwidth usage when conflicting transactions are broadcasted.

It delves into how Bitcoin nodes manage the prevention of double-spending through their mempools and considers the effect of different network topologies on the dissemination of transaction information.

In an idealized network structure where all Bitcoin nodes are arranged in a perfect ring, each connected to exactly two peers, the communication overhead for broadcasting two conflicting transactions (i.e., spending the same UTXO twice) is almost the same as that for a single transaction. The exception lies with a minimal number of nodes at the periphery of this network arrangement, which would encounter both versions of the transactions, thus marginally increasing the total bandwidth used.

The discussion further elaborates on how the increase in the number of connections per node affects the network's bandwidth consumption. Specifically, it points out that the additional bandwidth required to broadcast conflicting transactions grows proportionally with the increase in the number of peers per node. This observation underlines the scalability challenges faced by decentralized networks, particularly in scenarios where transaction conflicts arise.

For more detailed insights into these topics, the email references materials available at Peter Todd's website, encouraging readers to explore further discussions and technical documents related to Bitcoin's underlying technology and its operational nuances.