Zerotier CEO: Harvested Network Data Is Crypto’s Top Quantum Risk

Zerotier CEO Andrew Gault warned that adversaries are copying encrypted transaction traffic today with the intent to decrypt it when quantum computers become powerful enough. He called data moving between institutions the primary quantum threat to cryptocurrencies and described the tactic as “harvest now, decrypt later.”

Gault said attackers are storing interbank messages, payment authentication records and digital signatures. He argued that post-quantum cryptography only protects information created after systems upgrade, leaving previously captured traffic exposed to future decryption and possible forgery. “The financial system’s most dangerous vulnerability isn’t stored data, it’s the data moving between institutions right now,” he said.

The records Gault identified include settlement files, transaction confirmations and authentication logs. If those items are decrypted and altered later, past transactions could be questioned and legal liability reassessed, which would affect relationships among banks, exchanges and ledgers.

Industry responses vary. Ethereum began a coordinated post-quantum migration in 2026. Bitcoin has not adopted a comparable plan; its transactions use the elliptic curve digital signature algorithm (ECDSA), which is considered vulnerable to a sufficiently powerful quantum computer. Estimates for when such a machine could exist range from 2027 to 2035.

Developers and network communities have tended to favor voluntary transitions and to wait for mature standards from bodies such as the National Institute of Standards and Technology. That approach means data captured before a network-wide upgrade could remain at risk until upgrades are completed.

Zerotier has launched a product called Zerotier Quantum, a networking platform the company says meets high cryptographic benchmarks, including NIST standards used by the U.S. government. The company positions the product to protect data while it is in transit between institutions.

The discussion highlights a technical and governance question for distributed systems: how quickly can networks that require consensus implement cryptographic changes to protect traffic already moving across their networks while standards and migration plans are finalized?