Zakura Targets January for Quantum-Resistant Zcash Payments

Zakura is targeting January for post-quantum signature opcodes on Zcash’s transparent payment pool, a move designed to protect funds after spending exposes an address’s public key.

Zcash (ZEC) had 11,958,838 ZEC in transparent public UTXOs out of 16,976,561 issued coins at 5:39 a.m. ET (9:39 a.m. UTC) Oct. 9. That represented 70.4% of issued supply.

The planned signatures will use hash-based cryptography as a fallback for transparent addresses whose public keys are revealed when they spend funds. No mainnet activation date has been set.

“Our team plans for post-quantum signature opcodes to land in Zcash in January,” Roman Akhtariev, an engineer at Zakura, wrote.

A transparent address initially exposes only a hash of its public key. Spending from that address publishes the key, creating a potential future risk if an advance in computing allows attackers to derive private keys from public keys. Moving remaining funds to a fresh address can place them behind a new public-key hash.

Zakura is also developing a private-information-retrieval system for wallet balance and transaction-history checks. The design is intended to prevent servers from learning which addresses a wallet is querying or inferring that multiple addresses belong to the same user. An experimental version is available in the Vizor wallet.

The January target applies to Zcash’s transparent pool. Shielded pools conceal transaction details through different cryptographic mechanisms and require separate post-quantum safeguards.

The effort follows an Oct. 7 warning from Ethereum Foundation researcher Justin Drake, who urged the blockchain industry to plan a controlled migration toward addresses that keep public keys hidden behind hashes. Drake described a worst-case ECDSA failure occurring “in months not years,” but no practical attack has been reported.

Zakura’s stated January objective is: “And we achieve full post-quantum safe Transparent pools with hash based signatures in January.” The next concrete step is development work toward that January target; a network activation date remains unannounced.