Can Blockchain survive the threat of Shor's Algorithm and the Quantum Harvest?

All answers to this question.

The blockchain community is actively developing "Quantum-Resistant" signatures, primarily focusing on Winternitz One-Time Signatures (WOTS+) and Lattice-based schemes like Dilithium. The technical path involves a "Hard Fork" where users would have to move their funds to a new address generated with a PQC-secure private key. The real nightmare is the "Lost Coins." Millions of BTC are in wallets where the private key is lost. These cannot be moved and would eventually be "cracked" by a quantum computer. Some propose a "Burn and Claim" period where old addresses are eventually deactivated, but this is highly controversial in a decentralized ecosystem.

   Answered 2025-11-22 by Margaret White

Why not just use "Quantum Key Distribution" (QKD) to secure the nodes' communication instead of worrying about the signatures themselves?

   Answered 2025-11-24 by Steven Wright

• Steven, QKD only secures the "tunnel" between two points; it doesn't protect the "vault" where the data is stored. Even if the network communication is unhackable via QKD, an attacker with a quantum computer can still forge a signature for a Bitcoin transaction if the underlying algorithm is ECDSA. The signature is the "proof of ownership." If Shor's algorithm can derive the private key from the public key, the attacker can move the funds. We must fix the math at the signature level (PQC), as QKD is a hardware solution for a software-based vulnerability in the ledger's architecture.

     Commented 2025-11-25 by Paul Robinson

Ethereum is already looking at "Verkle Trees" and "STARKs" which are generally more resilient to quantum attacks than the current ECC-based proofs.

   Answered 2025-11-26 by Karen Scott

• Karen's point on STARKs is vital. Zero-knowledge proofs that don't rely on the "discrete log problem" are a massive head-start for the Ethereum ecosystem in a post-quantum world.

     Commented 2025-11-27 by Lisa Ray