Zakura, a developer of Zcash full node software, has proposed a way to stop a future quantum computer from linking users' private Zcash payments, in an engineering post by Zakura developer Adam Tucker announced on Sunday.
The approach needs no network upgrade, Zakura said in a tweet introducing what it called "post-quantum unlinkable swaps for Zcash."
Each swap out of ZEC writes one of the user's shielded addresses to NEAR's public chain as a refund address, whether or not a refund is ever made.
Zakura's fix derives a separate incoming viewing key for each address that has to be published, while leaving the account's spending key untouched.
"If a quantum computer ever breaks a posted swap address, it will not be able to link this to any other transaction," Tucker wrote in a Twitter thread.