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How Bitcoin survived a DoS attack now worth $24M

2025-07-11 16:04:25

Main Idea

In 2015, a group called CoinWallet.eu conducted a series of DoS attacks on Bitcoin to prove the vulnerability of its 1MB block size limit, spending 201 BTC (worth $49,000 then, $24M now) but ultimately failing to disrupt the network significantly.

Key Points

1. CoinWallet.eu launched four attacks between June and September 2015 to demonstrate Bitcoin's vulnerability to spam transactions due to its 1MB block size limit.

2. The attacks caused temporary backlogs, with one wave flooding the network with 27,000 to 80,000 transactions, including dust transactions sent to notable addresses.

3. The group spent a total of 201 BTC (worth $49,000 in 2015, now valued at ~$24M) but failed to achieve lasting disruption due to miner and community countermeasures.

4. An academic study found that at the peak, 23% of transactions were spam, increasing fees by 51% and processing delays by 7x, but the network adapted quickly.

5. The attackers' identity remains unknown, with speculation including figures like Craig Wright or Gerald Cotten.

Description

Big blockers wasted a bitcoin fortune trying to prove a point

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