Bitcoin developers are trying to build quantum defenses. Your coins could pay the price.

Bitcoin BTC$73,984.97 was built on a promise that no one can touch your coins without your private key. No government, no bank, nobody.

That promise is now, for the first time in Bitcoin's 16-year history, being challenged from the developer community itself, as a part of measures to build defenses against future quantum computers that could compromise Bitcoin's blockchain and steal your coins.

The proposal

Jameson Loop, one of the outspoken bitcoin contributors, and other cryptographers, have proposed a move that could force bitcoin holders to migrate their coins to new quantum-resistant addresses or face having their coins frozen permanently by the network itself. In that scenario, holders would technically still “own” the coins, but lose the ability to move them.

It is called Bitcoin Improvement Proposal (BIP)-361 and was updated in Bitcoin's official proposal repository Tuesday with the title "Post Quantum Migration and Legacy Signature Sunset."

This comes as a recently released Google report warned that a sufficiently powerful quantum machine could require significantly less firepower to compromise the Bitcoin blockchain than initially estimated. This prompted some observers to cite 2029 as the quantum deadline for bitcoin.

To understand the need to freeze coins, you need to know what it is protecting against.

Every Bitcoin wallet is secured by a form of cryptography called ECDSA, or Elliptic Curve Digital Signature algorithm. Think of it as a lock on your wallet. When you set up a wallet, two keys are generated: Private key, which is a unique password used to prove that you own the coins you are spending. Then there is a public key derived from the private key. This public key helps receive funds, verify transaction signatures, and ensure security without revealing the owner's private key.

Here is the problem: your public key is revealed on the blockchain, permanently for anyone to see when you send funds. A sufficiently powerful quantum machine can use it to reverse engineer your private key and drain your funds.

As of March, the sum of all BTC in vulnerable addresses was approximately 6.7 million BTC, according to the Google study.

BIP-361 builds on the proposal put forward in February under BIP-360, which introduced a soft fork—a network upgrade—designed to enable a new transaction type called pay-to-Merkle-root (P2MR). The approach borrows from Bitcoin’s Taproot (P2TR) framework, but strips out the key-based spending path, removing an element widely viewed as exposed to potential quantum-era risks.