Key Takeaways
- Kostas Chalkias says he leased a factory to build quantum-safe Sui wallet cards at scale.
- The target: under $10 per quantum card key and 1-2 seconds per NFC quantum signature.
- The move follows a Coldcard firmware flaw that drained about $130 million in BTC since July 30.
A Personal Mission
Kostas “Kryptos” Chalkias, co-founder and chief cryptographer at Mysten Labs, the company behind the Sui blockchain, revealed that he has been working on affordable quantum two-factor authentication (2FA) cards for Sui, adding:
“Last year, with help from some friends, I leased a dedicated factory in a secret location to build quantum-safe wallets at scale”
He has set a target of under $10 per quantum card key and 1-2 seconds per NFC quantum signature. Chalkias said he took on the project using personal time outside his day job, and that he may go as far as sponsoring the cards for users who can’t afford them.
Moreover, he directly referenced the recent Coldcard hardware wallet disaster as an added impetus to his ongoing mission, writing:
“What happened to Coldcard will NEVER happen to my people.”
Coinkite, maker of the popular Coldcard hardware wallet, disclosed in late July that a firmware flaw dating back to a 2021 update had bypassed the device’s dedicated hardware randomness chip during key generation, substituting a predictable software-based process tied in some cases to values like device serial numbers.
Attackers began draining funds on July 30, and losses climbed in waves: roughly 594 BTC in the first wave, about 1,082 BTC by Aug. 1, and an estimated 2,055 BTC, worth close to $130 million, from more than 7,700 addresses as the exploit spread. Galaxy Research’s head of research, Alex Thorn, said at least 15 different attackers were working through the remaining vulnerable wallets.
And, while the Coldcard flaw wasn’t a quantum attack, it illustrated the same underlying risk Chalkias is trying to get ahead of, i.e. hardware wallets that quietly fail at the cryptographic level, become potential attack vectors until the funds start moving.
Sui’s Broader Quantum Roadmap
The $10 wallet project builds on work already underway at the protocol level. Sui has said it plans to add two signature schemes approved by the National Institute of Standards and Technology (NIST) for quantum resistance, one designed for everyday accounts and a second for high-value Move-based vaults.
Existing Sui accounts would be able to rotate into a quantum-safe key derived from their existing recovery phrase rather than requiring a full migration to a new wallet. Chalkias has put forth Sui’s ability to swap in new authentication methods, including post-quantum cryptography, as a structural advantage over chains that would need a more disruptive hard fork to make the same change.
