How Reliable Are Hardware‑Based Crypto Wallets?

A surge of involvement successful self‑custody has pushed hardware wallets from a niche solution into the mainstream space. In the aftermath of speech collapses and large‑scale hacks, investors progressively question devices that committedness to clasp backstage keys offline and retired of scope of attackers. Yet hardware wallets are not immune to compromise. Researchers successful caller years person documented supply‑chain manipulation and firmware spoofing attacks that undermine instrumentality information agelong earlier a idiosyncratic ever enters a effect phrase. Those discoveries person raised a question cardinal to self‑custody: however reliable are hardware wallets erstwhile adversaries tin tamper with components oregon codification earlier they scope customers?

Evolving threats are aft the hardware wallets

The astir notorious of the caller onslaught classes emerged successful 2024. Known arsenic Dark Skippy, the method modifies the firmware connected hardware wallets truthful the instrumentality generates anemic cryptographic nonces and gradually leaks bits of the backstage cardinal done transaction signatures. Because the firmware tin fell this exfiltration, victims whitethorn not realise thing is incorrect until the attacker has reconstructed their cardinal and drained their funds. Dark Skippy highlights a much wide weakness: galore hardware wallets person firmware that tin beryllium updated, enabling an adversary who compromises a proviso concatenation to instal malicious code.

Supply‑chain interception attacks exemplify a parallel risk. In respective reported cases, criminals intercepted shipments, replaced unafraid chips oregon loaded modified firmware, and resealed the boxes. Victims received devices that looked genuine but contained microcontrollers with disabled flash representation protection; the hacked firmware utilized predetermined effect phrases and constricted passphrase options, giving attackers control. Such attacks are hard to detect. A researcher from Kaspersky lab, portion comparing morganatic and counterfeit Trezor devices recovered that the fake utilized a antithetic microcontroller and lacked a bootloader integrity check, allowing malicious codification to run. In 2025 researchers from Ledger Donjon demonstrated that a voltage‑glitching onslaught against the microcontroller successful Trezor’s Safe 3 and Safe 5 wallets could unit the instrumentality to make predictable seeds. Because compromised devices tin walk arsenic brand‑new, information experts urge purchasing lone from manufacturers oregon authorised resellers and verifying firmware authenticity.

A ”monolithic” counter-approach

In reaction, Swiss institution Tangem AG has positioned its devices arsenic a bulwark against supply‑chain and firmware manipulation. Founded successful 2017, Tangem archetypal offered credit‑card‑shaped NFC wallets and much precocious introduced a ceramic ringing that functions arsenic a wearable hardware wallet. Both products are built astir a highly unafraid “monolithic” chip; the firmware and backstage cardinal generator reside wrong the spot and cannot beryllium modified externally. Tangem says the card’s spot is certified to Evaluation Assurance Level 6+, a information people comparable to that utilized successful e‑passports and authorities ID cards.

During archetypal activation, the spot uses a hardware random fig generator to make the backstage cardinal offline. The Tangem app does not make oregon store the key; it simply facilitates transactions. According to institution documentation, the firmware is burned into the spot erstwhile during manufacturing and cannot beryllium updated. That plan eliminates the anticipation of malicious firmware updates but besides prevents users from patching aboriginal vulnerabilities. To combat counterfeit devices, the Tangem app verifies the authenticity of some the spot and firmware erstwhile the wallet is scanned. If the scan does not punctual a wallet‑creation process, the institution advises users to reset the card.

Tangem’s flagship ringing extends this architecture into a wearable signifier factor. The ringing is made of zirconia ceramic with an IP69K standing for h2o and particulate absorption and uses the aforesaid EAL6+ unafraid element. It supports sending, receiving, buying, swapping and staking cryptocurrencies via NFC and includes 2 backup cards; the backstage cardinal is distributed crossed the ringing and cards truthful that losing 1 does not compromise the wallet. A brute‑force extortion diagnostic adds a hold aft incorrect passcode attempts, reducing the hazard of unauthorized access.

Claims of unmodifiable firmware person been backed by autarkic audits. In precocious 2023, Tangem commissioned an audit from a Dutch supplier Riscure, a steadfast that specialises successful hardware security. Riscure examined the...