Trezor Responds to Coldcard Incident: Self-Custody Remains Sound Despite Security Flaw

Following the recent Coldcard security incident in which users lost funds due to a flaw in seed randomness generation, hardware wallet manufacturer Trezor has issued a statement emphasizing that the event, while serious, does not undermine the fundamental principles of self-custody or the reliability of hardware wallets as a category.

What Happened with Coldcard

The Coldcard incident involved a critical failure in one of the core functions of a hardware wallet: generating solid randomness for the seed. Affected wallets were built with weak randomness at the time of creation, which allowed attackers to drain funds. Trezor described this as a specific flaw in a specific company's product with no bearing on how other manufacturers' devices generate keys. Seed randomness is foundational to cryptocurrency security — if the random number generator produces predictable outputs, the resulting private keys can be mathematically reconstructed by an attacker.

Users whose wallets were manufactured correctly are unaffected. Their funds remain secured exactly as they were before the incident.

Fear Should Not Drive Security Decisions

Trezor cautioned against reactive changes to security setups, noting that fear-driven decisions often lead users to adopt complexity they do not fully understand, which itself introduces risk.

The discussion around multisignature (multisig) wallets has intensified since the incident. Multisig requires multiple keys to authorize transactions, meaning no single device or vendor can compromise all funds. Trezor has supported multisig since 2014 and is among the most widely used devices in such configurations. However, the company noted that multisig is not universally necessary.

For many users, a straightforward single-signature setup remains effective: one seed phrase, written down and stored securely. Multisig carries its own challenges, including the risk of falling below the required signature threshold, difficulty in backup and restoration, and annual fees for managed versions. Trezor advised newcomers to start small and not be discouraged by the incident.

The Custody Question: Who Holds Your Keys?

Since news of the Coldcard incident broke, some Bitcoin has moved back to exchanges and custodial services as users seek what feels like a simpler and safer alternative. Trezor pushed back against this trend, arguing that it reverses the core lesson.

The fundamental reality, Trezor stated, is that someone always holds the keys to any Bitcoin holding. If the user does not hold them personally, then a company does, and the user must trust that company to remain honest, competent, and solvent.

The cryptocurrency industry has witnessed repeated failures of custodial trust. The 2022 collapse of FTX left hundreds of thousands of creditors unable to access billions in assets. The 2014 Mt. Gox hack resulted in the loss of approximately 850,000 Bitcoin. More recently, Celsius and BlockFi both froze withdrawals before declaring bankruptcy the same year. Users who believed their assets were safe with third parties have discovered, often too late, that they never truly controlled those assets.

Trezor drew a distinction between trusting a custodian and trusting a hardware wallet manufacturer. With a custodian, users surrender the assets themselves and rely on the company's continued solvency and honesty. With a hardware wallet, users retain custody and rely only on the tool being correctly built. Because Trezor's code is open source, this claim can be independently verified rather than taken on faith.

Making Self-Custody Accessible

Trezor acknowledged that responsibility is the inherent trade-off of self-custody but argued that the industry's task is to make that responsibility feel manageable.

The company challenged the long-standing assumption that self-custody is inherently difficult and that convenience belongs exclusively to exchanges. Trezor's position is that convenience, more than difficulty, drives where people store their Bitcoin. Most users leave assets on exchanges not because they have assessed and accepted the risk, but because the process was quick and familiar.

The goal, Trezor stated, should be to make holding one's own keys as intuitive as using everyday applications. Security is not about elaborate setups or air-gapped configurations. A solid single-signature wallet serves as a practical baseline, and users who wish to can scale up from there.

Open Source as Verifiable Trust

Trezor emphasized that its firmware and device designs are fully open source, allowing anyone to inspect exactly how a Trezor device operates, including the specific methods used to generate the randomness that protects user funds. Trezor, produced by SatoshiLabs, shipped the first widely adopted Bitcoin hardware wallet in 2014 and has maintained that open-source posture throughout its twelve-year history.

The company cautioned that open source is not automatically a guarantee of security. Open code only provides value when people actually review it. To that end, Trezor operates a bug bounty program that compensates independent researchers for identifying and reporting vulnerabilities. Because the code is public, scrutiny is continuous rather than limited to selected occasions.

Trezor framed transparency not as an add-on but as a foundational design principle, aligning with Bitcoin's original purpose: enabling verification rather than demanding blind trust.

Industry-Wide Scrutiny and Strengthened Security

Trezor noted that incidents like the Coldcard failure, while painful, compel the entire industry to conduct deeper audits and ask harder questions. The resulting scrutiny from researchers, new tools, and the broader community ultimately strengthens self-custody infrastructure.

The company reported that over the past week it has welcomed many new users, a significant number transitioning from Coldcard, who remain committed to self-custody. Trezor, which has been operating for twelve years, stated it will continue serving these users as it has all others.

Trezor reiterated its core position: after every failure the industry has witnessed, the safest hands for Bitcoin remain the owner's own.

Source: Bitcoin.com