Coldcard Vulnerability Shakes Self-Custody Trust

Kevin Loaec was invited to the Origin Seoul 2026 conference specifically to address the recent Coldcard situation. He indicated that without this critical event, his presence at the conference would have been unlikely. Loaec planned to lead a panel discussion focusing on self-custody and conduct an interview with Stefan Nea, delving deeper into the specifics of the Coldcard issue.

The Coldcard bug proved to be extremely severe, with many users losing all their Bitcoin assets. Kevin Loaec recounted receiving direct messages from individuals who had been involved with Bitcoin for over a decade and had tragically lost everything. He described the situation as catastrophic, highlighting the profound and devastating impact on those affected by the security vulnerability.

Ironically, many of the victims were individuals who had diligently followed security best practices, embracing self-custody to avoid risks associated with third parties like ETFs or exchanges. They adhered to standard protocols, including generating their own entropy and refraining from connecting their hardware wallets to computers. These users placed the blame squarely on the hardware itself, rather than any perceived negligence on their part.

The Coldcard incident makes it extremely challenging to advocate for self-custody, especially to non-technical individuals, after years of telling them it is the safest option to prevent loss. Kevin Loaec acknowledged the difficulty but reiterated that despite such incidents, self-custody remains the highest security standard. Rebuilding trust in this practice will require a prolonged and concerted effort from the Bitcoin community and hardware manufacturers.

Current AI models are still at the level of 'average engineers' rather than expert developers capable of identifying novel and complex attack vectors. Kevin Loaec noted that while AI excels at rapidly and affordably detecting common vulnerabilities, it is not yet equipped to find sophisticated, never-before-seen bugs. He highlighted that a core challenge in open-source projects is the lack of human incentive for thorough code audits, a gap that AI can partially fill by automating the detection of known issues.

While open-source software is often promoted for its security due to public code visibility, this does not automatically translate to constant, thorough reviews by everyone. Kevin Loaec explained that genuine code review demands significant time, effort, and financial resources. He criticized companies like Coldcard for not offering sufficient incentives, such as bug bounties, to encourage diligent and comprehensive security audits from the broader community.

Kevin Loaec explained that AI can act like a dedicated team of a hundred engineers constantly auditing code, significantly enhancing security. This intensive scrutiny by AI will lead to the discovery and rectification of many existing hidden bugs. Even small projects will be subjected to this heightened level of examination, making software inherently stronger and more reliable against vulnerabilities.

The industry is currently in a transitional, somewhat chaotic phase, as it moves towards achieving higher standards of software security. Kevin Loaec acknowledged that while the ultimate goal is highly secure software, the path to reach this level can be quite messy. This period of disruption is seen as a necessary part of the evolution toward more robust and reliable systems.

The emergence of new open-source AI models marks a fresh epoch in Bitcoin, making it impossible for companies to conceal security flaws. Kevin Loaec stated that the era of simply claiming perfection without validation is over, as AI tools will expose vulnerabilities. This new transparency will foster a healthier ecosystem, where genuine security is validated through rigorous scrutiny, rather than merely asserted.

The interviewer suggested that Korean Bitcoin users tend to be more 'paranoid' and proactive in securing their assets, possibly influenced by government monetary policies. This heightened sense of caution has led to the widespread adoption of practices like 'rolling dice' for entropy generation, which has become a standard in the Korean community. Users in Korea also frequently question the level of trust that should be placed directly in hardware wallet manufacturers.

While rolling dice is a valuable method, it is not a 'silver bullet' that addresses all security concerns, as the interviewer emphasized. This technique specifically targets issues related to entropy generation, ensuring randomness in seed creation. However, other risks persist, such as potential bugs in cryptographic libraries or vulnerabilities introduced through supply chain attacks. For truly robust security, a multi-signature setup involving diverse hardware brands is highly recommended to mitigate a broader range of threats.

Kevin Loaec asserted that no single solution can serve as a universal 'silver bullet' for all security vulnerabilities in the Bitcoin ecosystem. While theoretically, anything could be deemed a silver bullet, in practice, no such singular fix exists. Users must understand that methods like rolling dice are targeted solutions designed to address very specific problems, such as entropy generation. A comprehensive security strategy requires a layered approach, recognizing that different threats demand different countermeasures rather than relying on one-size-fits-all solutions.

Kevin Loaec explained that the motivation for building a new inheritance solution for Bitcoin stemmed from personal use cases, particularly his lack of trust in family members handling sensitive mnemonic backups. He clarified that this distrust wasn't due to concerns about theft, but rather the risk of mishandling—such as leaving a seed phrase on a coffee table instead of securing it properly. This highlights a critical challenge in self-custody: ensuring secure transfer and management of assets across generations while mitigating human error.

Lyanna Wallet introduces time-locked spending conditions, allowing users to define both a primary and a secondary path for coin access. The primary path enables normal wallet usage, whether it's a single-signature or multi-signature setup. The secondary path, however, only activates if the coins remain unmoved for a specified period, after which different keys—such as those belonging to family members—gain the ability to spend from the wallet. This entire mechanism operates natively on the Bitcoin blockchain, eliminating the need for trust in any central server.

Lyanna Wallet facilitates advanced key rotation, enabling the transition from complex multi-signature setups to simpler recovery keys as needed. The software supports multiple layers of key rotation, which is particularly beneficial for corporate entities managing significant Bitcoin holdings. It also incorporates automated fallbacks to different key sets if a primary participant departs or becomes deceased, ensuring continuous access and management of funds. This robust design makes Lyanna a versatile tool for implementing sophisticated multi-signature strategies alongside time-locked recovery and inheritance features.

Lyanna Wallet provides a crucial safety net for users who implement overly complex security measures, preventing self-inflicted lockouts due to human error. For instance, a user employing a highly secure five-of-five multi-signature setup might find themselves unable to access their funds if keys are lost or participants become unavailable. Lyanna allows for a programmable fallback where, under specific conditions, the threshold for spending could automatically reduce to a single signature, ensuring that funds remain accessible even in challenging recovery scenarios. This feature adds a practical layer of resilience to advanced security configurations.

Kevin Loaec's company, Wizard Sardine, specializes in Bitcoin security, offering comprehensive audit services for various components of the ecosystem. This includes security audits for Bitcoin Core, other hardware wallets, and general software solutions. Loaec also mentioned that he provides regular updates and insights through his X (formerly Twitter) account, keeping the community informed about developments in Bitcoin security.