Quantum, Schmantum — Zcash Devs Say Jan You Get Hash-Based Wallets 🛡️

Zcash developers at Zakura said they plan to add support for post-quantum signature opcodes to the network in January, with the network activation timeline still undecided. The opcodes would introduce hash-based signatures designed to protect wallets from future quantum attacks that could derive private keys from publicly visible on-chain data and forge transaction approvals. Zakura, which builds a Zcash full node, framed the work as delivering "full post-quantum safe transparent pools with hash based signatures" in an engineering post by Roman Akhtariev.

The proposal initially targets Zcash's transparent payment pools, where approximately 11.96 million ZEC sit in public addresses that together hold roughly 70% of the token's supply. Transparent addresses on Zcash work like Bitcoin's, keeping a hash of the public key hidden until the owner spends from the address, at which point the key is revealed on-chain. To keep those keys out of view, its approach rotates to a fresh address after every transaction and pairs each address with a WOTS hash-based backup signature, avoiding the elliptic-curve math researchers fear could eventually be broken by advanced AI or quantum machines.

The team said rotation introduces a linkability problem, since a wallet asking a server to check balances across many addresses can reveal that they share an owner, and that it is addressing the issue with private information retrieval, or PIR. The feature is rolling out this week in the Vizor wallet, where users can test it by toggling "private queries" in the settings. "While others are worrying about the viability of rotating transparent addresses, we're already solving linkability," Zakura wrote on X.

The push lands as Ethereum Foundation researcher Justin Drake this week urged holders to move funds to fresh addresses, warning that AI-driven math could break ECDSA signatures securing Bitcoin and Ethereum before quantum computers do, "in the worst case in months not years." Ethereum co-founder Vitalik Buterin has since weighed in on the debate and said he believed it was "plausible" that AI-driven advancements in math could break encryption within the next two years.

The Zakura plan covers only Zcash's transparent side, and the post did not specify how or when the opcodes would be activated across the network. Traders pushed the 24-hour rebound in ZEC price to more than 11%. The announcement also comes as Zcash draws growing institutional interest, including another proposed U.S. ETF tied to the Winklevoss twins and Europe's first Zcash ETP, and follows an upgrade designed to make private payments three times faster.