New attack identified and potential solution described: Dropped-transaction spam attack against the blocksize limit

Summary:

The Bitcoin Core mempool does not drop transactions with insufficient fees unless they are double-spent or the node restarts. This is problematic because the only protection against a spam attack is a high amount of access to bitcoins for paying fees. Without a block size limit, this attack would simply result in a transfer of wealth from spammer to miners, which is an antifragile response for the Bitcoin network. While there is no current memory pool cap, hardware limitations prevent memory pool sizes from growing unbounded. Capping the size of the mempool and evicting lowest fee/KB transactions first is a solution but it breaks zeroconf security. If zeroconf security is not broken, then attackers can prevent reasonable fee transactions from propagating over the network.

Updated on: 2023-06-09T22:39:52.587039+00:00