Coldcard's hardware wallet security breach led to the loss of over $70 million in Bitcoin, raising concerns about the safety of non-custodial storage.
The collapse of FTX in 2022 led to a surge in demand for hardware wallets, benefitting manufacturers like Coldcard, which branded itself as a uniquely secure option for Bitcoin storage. With its "Sleep at Night Technology" slogan, Coldcard emphasized uncompromising security, becoming a go-to choice among Bitcoin enthusiasts. However, a recent incident has severely undermined this reputation.
On July 30, 2026, an unknown hacker exploited vulnerabilities in Coldcard wallets, draining approximately 1,431.97 BTC (around $70.2 million) from over 5,400 addresses in a series of transactions. This breach is particularly alarming as it occurred without direct access to any devices, raising critical concerns about the security of hardware wallets.
Details of the Breach
Galaxy Research reported that a significant amount of Bitcoin was transferred from multiple addresses in a short time frame, indicating a coordinated attack. Coinkite, the manufacturer of Coldcard, identified the cause as a flaw in the integration of a cryptographic library used in their wallets. This error resulted in a significant reduction of the expected security, leaving many users vulnerable.
Coldcard's products, particularly the Mk2 and Mk3 models, suffered from a drop in security from 128 bits to approximately 40 bits due to this integration issue. Although Coldcard maintained that its dice rolls could provide additional randomness, not all users employed this safeguard, which has led to widespread losses.
Recommendations for Affected Users
In light of the breach, Coinkite has recommended that users of affected models take urgent steps to secure their assets. This includes checking firmware versions, generating new seed phrases on corrected firmware, and transferring funds to secure addresses. Users are also advised against relying solely on passphrases as a security measure, as weak seed phrases can significantly compromise safety.
Industry analysts suggest that the best defense against such incidents now involves using multisig setups across different hardware wallets, although this approach is complex and may not be suitable for all users.
Loss of Trust in Non-Custodial Models
The incident has raised broader concerns about the reliability of non-custodial storage models. Following the breach, a notable increase in Bitcoin deposits on exchanges was observed, as some users opted for the perceived safety of custodial solutions. This shift in behavior highlights a growing distrust in hardware wallets, which were once viewed as the safest option for storing cryptocurrencies.
Coinkite has released emergency firmware updates and taken responsibility for the error, with CEO Rodolfo Novak expressing deep regret over the situation. However, no compensation for affected users has been announced, leaving many in the community feeling vulnerable and uncertain about the future of hardware wallet security.
As the crypto industry grapples with this incident, discussions around the intersection of artificial intelligence and security vulnerabilities have emerged, suggesting that AI may have played a role in discovering the flaw. The implications of this incident may have lasting effects on user confidence and the adoption of hardware wallets moving forward.
