Bitcoin Satoshi’s Vision [BSV] has been in the news recently due to its inflated price growth over the past week. However, a programmer and computer security researcher is known as Reizu recently found that, among other things, it is possible to double spend a zero-confirmation transaction on the BSV chain.
He also discovered that the hashrate on the network is also highly concentrated, with just 4 nodes controlling over 75% of the hashrate, out of the 450 nodes on the network. He begins by saying that double spending a 0-conf transaction is possible, but restricted by multiple real-world limitations. These include the fact that the propagation of transactions is very fast on the Bitcoin network, and that miners follow the “first seen safe” rule.
Moreover, whenever fees of greater than 1 satoshi/byte are used, the transaction is considered safe. In case of double-spending actually occurring, it is easy to detect it by connecting to several different nodes and waiting for 5 seconds, as that would effectively show if transactions have the same output.
Reizu stated that the main reason he picked Bitcoin SV is that the community believes that 0-conf transactions are safe, and said that he wanted to see whether it was possible to send a transaction to one node and another transaction with the same input to another node. He discovered that he indeed could, and presented a short tutorial doing so, using a tool known as izubitcoin.
The tool has some features that enable this, such as using parallelization to connect to each node on the network and connecting to the Bitcoin protocol natively. He explained:
“Once connected to the remote nodes (after a few seconds) I send a signal to the processes. Upon receipt, each thread sends the transaction to their node and disconnects.