By The Biggest Bitcoin Hacks in History
Billions of dollars in crypto have been stolen over the years, and headlines routinely call every one of these incidents a "Bitcoin hack." Almost none of them involved anyone breaking Bitcoin's actual cryptography. This is a rundown of the largest incidents and, in each case, what was really compromised.
Mt. Gox (2011 to 2014)
The largest and most consequential crypto exchange failure in history. Once handling over 70 percent of global Bitcoin trading volume, Tokyo-based Mt. Gox revealed in 2014 that approximately 850,000 BTC belonging to customers and the company had disappeared, later attributed to years of gradual theft through compromised internal systems and weak wallet security practices, not a break of Bitcoin's cryptography. The exchange collapsed into bankruptcy, and creditor repayments were still being finalized more than a decade later.
Bitfinex (2016)
Attackers stole roughly 120,000 BTC from the Bitfinex exchange by exploiting a vulnerability in how the exchange's multi-signature wallet system was implemented alongside a third-party security provider, not a flaw in Bitcoin itself. This case had an unusual coda: in 2022, US authorities arrested a couple and recovered a large portion of the stolen funds, one of the largest crypto seizures ever conducted.
Coincheck (2018)
Japanese exchange Coincheck lost around $530 million worth of a different cryptocurrency (NEM, not Bitcoin) after attackers accessed a hot wallet that, unlike best practice, was connected to the internet and not protected by multi-signature security. Again, an exchange infrastructure failure rather than a cryptography break.
Ronin Network / Axie Infinity (2022)
Attackers linked to North Korea's Lazarus Group stole around $625 million by compromising five of nine validator private keys controlling the Ronin bridge, a system connecting the Ronin blockchain to Ethereum. This one is closer to a genuine private key compromise, but the keys belonged to a specific bridge infrastructure project, obtained through social engineering of employees, not brute-forced or derived from Bitcoin's cryptography.
FTX (2022): fraud, not a hack
FTX's collapse is frequently lumped in with hacks, but it wasn't one. Billions in customer funds were misused internally by the exchange's own executives. FTX founder Sam Bankman-Fried was convicted on multiple counts of fraud and conspiracy in 2023. No cryptography was broken; customer trust and internal controls were.
What these all have in common
- Every major incident targeted a company's infrastructure, hot wallets, internal access controls, or personnel, not Bitcoin's underlying elliptic curve cryptography.
- The common failure was centralization: funds held by a single custodian in wallets connected to the internet are a single point of failure in a way self-custodied keys are not.
- None of these cases involved anyone guessing or deriving a private key through brute force. Every one involved a system-level compromise: stolen credentials, insider access, or a flawed implementation.
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Try the key collider nowThe takeaway
The pattern across every major incident on this list is the same: Bitcoin's cryptography held, the companies and infrastructure around it didn't. For a deeper look at why the cryptography itself has never been the weak point, see Can Bitcoin Be Hacked?