A technical glitch in the core Bitcoin software forced developers to call for a temporary halt to Bitcoin transactions, sparking a sharp sell-off. The currency’s value briefly fell 23 percent to $37 before regaining much of its value later in the evening.
The core of the Bitcoin network is a shared transaction register known as the blockchain. Approximately every 10 minutes, a new block is created containing a record of all Bitcoin transactions that occurred since the previous block. Nodes in the network, known as miners, race to “discover” this next block by solving a cryptographic puzzle. The winner of this race announces the new block to the other nodes. The other nodes verify that it complies with all the rules of the Bitcoin protocol and then accepts it as the next official entry in the block chain, starting the race anew.
It’s essential for all miners to enforce exactly the same rules about what counts as a valid block. If a client announces a block that half the network accepts and the other half rejects, the result could be a fork in the network. Different nodes could disagree about which transactions have occurred, potentially producing chaos.
That’s what happened on Monday evening. A block was produced that the latest version of the Bitcoin software, version 0.8, recognized as valid but that nodes still running version 0.7 or earlier rejected…