Zcash Developers Propose Quantum-Resistant Privacy Fix for NEAR Intents

The Proposed Fix

Zakura, the Zcash infrastructure team, has proposed that each ZEC swap executed through NEAR Intents receive its own dedicated viewing key. The change is designed to ensure that refund addresses left on NEAR's public chain cannot be used to reconstruct or expose a user's wider transaction history, even in a scenario where quantum computers break the underlying cryptographic assumptions that currently secure the chain.

How It Works

Under the current flow, users swap ZEC through NEAR Intents and may leave refund addresses or other identifying information on NEAR's public ledger. Because NEAR's transactions are visible on-chain, a determined adversary with quantum computing capability could theoretically correlate these addresses across multiple swaps to build a profile of a user's payment behavior. By issuing a unique viewing key per swap, Zakura would compartmentalize the relationship between each transaction and its associated on-chain footprint, making that kind of historical reconstruction significantly harder.

Quantum Threat Timeline

The proposal reflects a broader industry trend of preparing defenses against post-quantum cryptography risks, though practical quantum computers capable of breaking elliptic-curve or other conventional encryption schemes remain years or decades away. Zakura detailed the approach in an engineering post, framing it as part of ongoing hardening work for Zcash's privacy model as it integrates more deeply with other chains and protocols.