The Zcash development team plans to assign a unique viewing key for each ZEC cross-chain swap to mitigate future quantum computing risks.

On October 19, according to CoinDesk, the development team for the new Zcash node software, Zakura, plans to generate a unique viewing key for every ZEC conversion conducted via NEAR Intents, while the spending key will remain under the custody of the user's primary account.

In this context, when users convert private ZEC to USDC via NEAR Intents, one of their Zcash privacy addresses is publicly posted on the NEAR public blockchain as a refund address and remains there after the conversion is completed. While this address currently does not leak any information, sufficiently powerful quantum computers in the future could potentially reverse-engineer the viewing key using Shor’s algorithm, thereby linking all payments, amounts, and memos received by that account. Adopting a “one key per conversion” approach ensures that even if a specific refund address is compromised, attackers can only view payments related to that individual conversion.

To address the need for sequential full-chain scans during wallet recovery caused by managing a large volume of keys, Zakura implements Private Information Retrieval (PIR) technology, allowing wallets to query refund settlement locations without the database being able to determine which address was queried.