Bitcoin SV (BSV) May be Vulnerable to Double Spending

An advanced user demonstrated the possibility to double-spend Bitcoin SV (BSV) coins by using a zero-confirmation feature.

An advanced user has posted a video on Vimeo showing that Bitcoin SV (BSV) is vulnerable to double-spending. The user, reizu, noticed that most of the transactions he sent out were processed immediately by just four highly accessible nodes, making the Bitcoin SV network highly centralized, for now.

The user pointed out that four nodes control more than 70% of the Bitcoin SV hashrate, meaning the network is currently highly centralized. Nodes previously possible for regular users are now mostly supported by miners due to the greater technical requirements.

One of the ways to protect against double-spending is to require that each transaction propagates through as many nodes as possible, which may take hours. Zero-confirmation transactions are usually used for a faster shopping experience.

However, a merchant that accepts zero-confirmation transactions may see his goods taken away, along with the coins paid, which are reused in another transaction, this time confirmed. Zero-confirmation may mean a merchant accept a new state of the distributed ledger, before it has propagated in the network. This also shows that there are exceptions and blockchain transactions are not irreversible or guaranteed to be fair.

Bitcoin SV is a project that is now fighting for recognition, so troubles like a block reorg in the early days, and the potential for double-spending are working against the credibility of the network. However, the enthusiasm for the speculative spike in the price has overshadowed the concerns about security.

The project is seeing aggressive defenses from leader-figures Dr. Craig Wright and Calvin Ayre of the CoinGeek mining pool. Wright wrote a lengthy blog posting suggesting that double-spending may not be so easy for regular clients.

The BSV digital asset has given indications that it is not competing with the BCH ticker. Instead, the coin is gaining ground independently, as more exchanges are distributing BSV balances.

The market price of BSV is back down to $98.04, after briefly trading higher than the Bitcoin Cash (BCH) chain. BCH has returned to $107.47, but for now, it seems the two assets may see continued attempts at a trading war.

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