Abstract The solution is set Quantum Hash(HashQ) to avoid Quantum Attack. Placing Falcon algorithm after SHA256 to create Private and Public keys safe and strong. I have given this example with the Falcon. You can place the one You decide after due rational consensus, You can place the most compact signature, with robust security and efficiency. Always after SHA256. A parallel option is built on the same Bitcoin network, where there is a Quantum format network so that users can safely and privately migrate their bitcoins to save them from a Quantum attack. A function is built parallel to the current function in the running branch and thus both blockchains coexist: The classic one and the one robust to the Quantum attack. https://c.gmx.com/@1353820301439272152/Tff4B46bSOyzhKBKMZdA9A You do not need a hard fork, just add this parallel option function to create a solution without affecting the current one branch and giving the possibility for users to take refuge in this robust and secure option. In this system, mining incentives must be balanced and greater than current one. What I have proposed gives Bitcoin a Higher Binary level when it reaches the category of Parallel System in execution. This is applicable to any system, what I propose is the birth of Parallel Systems from the same running branch, without altering what was built and what will be built by the branch from which the Parallel System is executed. Both build independently on the same branch. Both co-exist!. https://crypto.unibe.ch/fc25/paper.php/70?cap=hcav70nCzgoMbFzntiotFRNeuiBQPA Satoshi Nakamoto PGP --> DE4E FCA3 E1AB 9E41 CE96 CECB 18C0 9E86 5EC9 48A1