Zcash Targets January 2027 for Quantum-Safe Signatures

Zcash developers are targeting January 2027 to add instructions that would let the network verify quantum-resistant signatures for payments. The target is a development milestone, not a confirmed date for activating the changes across the network, according to Zakura engineer Roman Akhtariev. The proposal would initially address transparent transactions, which expose payment details on the blockchain. Shielded payments, which conceal transaction information, require separate cryptographic safeguards against possible future quantum attacks. The planned work therefore would not make all Zcash transactions quantum-resistant. The new instructions are intended to support hash-based signatures, which use different cryptographic assumptions from the elliptic-curve signatures currently used for transparent spending. The approach is designed to reduce the risk that a future quantum computer could use an exposed public key to derive a private key and authorize a payment. Winternitz One-Time Signatures are among the constructions discussed, but the final implementation has not been specified in the reports. Data from ZecStats cited in the reports put 11.96 million of 16.