Study: a mistake in the course of hardfork Bitcoin Cash led to double spending of $ 1.4 million

During hardforka, an error occurred in the Bitcoin Cash network, which led to double spending in the amount of 3,392 BCH, which is about $ 1.4 million at the current rate. This is stated in the new report of the research division of the exchange BitMEX.

According to the document, the recent hardfork led to the appearance of several problems at once.

First, an error occurred that made it possible to “translate transactions that meet the conditions for the admissibility of the memory, but did not pass the consensus test.” As a result, miners produced empty blocks.

All this caused the concern of the miners, who, as stated in the BitMEX report, "tried to mine blocks in the original chain, which led to network separation."

As a result, the network ramification hindered the normal operation of the system designed to return funds randomly sent to SegWit addresses. This error could cause the reorganization of the two blockchains.

“According to our calculations, about 3,392 BCH were spent twice in an organized cancellation of the transaction. Nevertheless, the only victim in relation to these double-spent coins could be only the initial “thief”, ”the BitMEX report states.

The researchers concluded that one can learn a lesson from all these mistakes.

“Hardfork gives attackers the opportunity to attack and create uncertainty in the network, so careful planning and coordination is extremely important … Another key lesson, based on these events, is the need for transparency. During the incident, it was difficult to find out exactly what the developers planned, the nature of the errors that occurred, or which chain was maintained by the miners. ”

Recall that hardfork in the Bitcoin Cash network took place on May 15th. Already then, BitMEX researchers reported that after the upgrade, the network was faced with technical problems.

Later it became known that the large mining pools BTC.com and BTC.top carried out a “51% attack” to cancel the transaction of another miner who tried to gain access to funds that did not belong to him.

In this way, they actually subjected the network to severe censorship, although their intentions seem to be good.