Zakura proposes separate viewing keys for Zcash swaps

Zakura has proposed a wallet-level change for Zcash swaps that would give each swap address its own incoming viewing key, limiting the transaction history exposed if a future quantum computer were able to recover a key from a publicly recorded address. The proposal targets swaps made through NEAR Intents, which can publish a shielded Zcash address on NEAR’s public blockchain as a refund or receiving address. Although the address may remain visible even when no refund is needed, Zakura says current computers cannot use it to recover the viewing key. The quantum threat is theoretical; no quantum computer capable of recovering Zcash keys has been publicly demonstrated. Zcash accounts normally use one incoming viewing key across their shielded addresses. In an engineering explanation, Zakura developer Adam Tucker said a sufficiently powerful quantum computer could theoretically recover that shared key from an exposed address and link payments received across the account. The proposed design would derive a separate viewing key for each swap address, while leaving the account’s spending authority unchanged. A recovered key would then expose payments associated with that address,...