Zcash Zakura Developers Propose Per-Swap Viewing Keys to Shield NEAR Swaps From Quantum Attacks

The engineering team behind Zakura, a newer software client for the Zcash $ZEC network, has proposed assigning a unique viewing key to every cross-chain token swap executed through NEAR Intents to protect historical user privacy from future quantum computers. When users swap private ZEC for USDC via NEAR Intents, the service posts a private Zcash refund address onto NEAR's public blockchain as soon as the deposit lands, where it remains permanently even if no refund is required. While standard computers cannot reverse the elliptic-curve math protecting these addresses, a sufficiently powerful quantum computer running the 1994 Shor's algorithm could theoretically derive the underlying viewing key from a single published refund address and link every payment, amount, and memo associated with that wallet. To prevent wallet restoration backups from having to scan the entire Zcash blockchain with hundreds of separate swap keys, Zakura's design uses private information retrieval so wallets can query a database for refunds without revealing which addresses they are checking. Zakura stated that software wallets built on its open-source libraries, including Vizor, could integrate the feature within weeks ahead of the broader January target Zcash developers set for quantum-resistant payments, while hardware wallets will require firmware support.