Sui co-founder leases factory for $10 quantum-safe wallet cards

Kostas Chalkias, co-founder and chief cryptographer at Mysten Labs, has leased a factory to mass-produce quantum-resistant hardware wallet cards for the Sui blockchain. The devices are intended as an affordable secondary authentication factor and are being developed in Chalkias’ personal time.

Chalkias set two technical targets for the project: keep production cost below $10 per card and deliver near-instant NFC quantum signatures that complete in one to two seconds. He wrote that he began the effort last year and established the production site with help from friends, adding that he may sponsor cards for users who cannot afford them. “Last year, with help from some friends, I leased a dedicated factory in a secret location to build quantum-safe wallets at scale,” he wrote. He also warned, “What happened to Coldcard will NEVER happen to my people.”

The announcement follows a hardware wallet breach linked to a firmware flaw that affected a widely used device. A 2021 firmware update bypassed the device’s hardware randomness during key generation and used a predictable software process in some cases. Attackers began draining funds on July 30. Losses rose in stages: about 594 BTC in an initial wave, roughly 1,082 BTC by Aug. 1, and an estimated 2,055 BTC — near $130 million — from more than 7,700 addresses as the exploit spread. Security researchers reported at least 15 different actors moving through vulnerable wallets.

Chalkias’ cards use post-quantum cryptography in a physical form factor. The cards are designed to resist attackers using future quantum-capable machines and to protect against classical cryptographic failures in devices. Chalkias described the goal as producing large volumes of low-cost cards that perform quickly enough for everyday use as an NFC-based second factor.

Sui’s protocol work aligns with the hardware effort. The network plans to add two signature schemes approved by the U.S. National Institute of Standards and Technology for quantum resistance: one aimed at routine accounts and another for high-value Move-based vaults. Sui has proposed a key-rotation path that would let existing accounts derive a quantum-safe key from their current recovery phrase, avoiding a full wallet migration. Chalkias noted Sui’s ability to change authentication methods without a disruptive hard fork.

Details on manufacturing, exact distribution plans and timelines remain limited. Chalkias has emphasized building at scale from the leased factory but has not released production volumes or launch dates. The Coldcard incident was not caused by a quantum attack; it highlighted how failures in device key generation can leave many wallets exposed until funds are moved, and it has prompted interest in stronger device-level protections and alternative authentication approaches such as quantum-resistant cards.