[Researcher Proposes Bitcoin Quantum-Resistant Transaction Scheme Without Forking] Deep Tide TechFlow reports, on April 12, according to Decrypt, StarkWare researcher Avihu Mordechai Levy recently published a paper proposing a transaction scheme called 'Quantum Secure Bitcoin (QSB).' This scheme enables Bitcoin transactions to resist quantum computing attacks without modifying the Bitcoin protocol, requiring a soft fork, or network upgrade. The proposal replaces the existing Elliptic Curve Digital Signature Algorithm (ECDSA) with hash-based cryptography and Lamport signatures, which are considered resistant to attacks by quantum computers running Shor's algorithm. The core of the scheme is an off-chain cryptographic puzzle that must be solved before broadcasting a transaction. The paper estimates that finding a valid solution would require approximately 70 trillion attempts, but it could be completed using consumer-grade hardware like GPUs at a cost of a few hundred dollars. The computation result is then submitted to the network along with the transaction. Additionally, the scheme introduces a 'transaction pinning' mechanism, requiring any attacker attempting to tamper with the transaction to resolve the puzzle again. Levy acknowledges several limitations of the scheme: the off-chain computational cost and the on-chain transaction size make it difficult to meet Bitcoin's target throughput; the transaction creation process is more complex than standard operations and may be considered non-standard, requiring direct submission to mining pools rather than broadcasting through the public mempool. Furthermore, Grover's algorithm could still provide quantum attackers with a quadratic speedup advantage. Levy positions this scheme as a 'last resort' rather than a scalable, permanent solution and emphasizes the need for further research and implementation of more robust quantum-resistant solutions through protocol-level changes. Currently, the quantum threat to Bitcoin remains theoretical, but companies like Google and Cloudflare have already begun preparations, setting a target to complete post-quantum migration by 2029.