Quantum computing is advancing rapidly, offering new technological possibilities, but also bringing considerable challenges to the security of essential digital infrastructures like Bitcoin, which relies on robust cryptography to ensure transaction integrity.

Currently, Bitcoin is protected by elliptic curve cryptography (ECDSA). This method is highly efficient and secure in a classical computing scenario, resisting conventional attacks. However, there is a view that quantum computing could destabilize this security, with the potential to break traditional cryptographic systems exponentially faster. This is not entirely accurate.

Impact of Quantum Computing on Bitcoin

Quantum computing, through Shor's algorithm, has the ability to perform tasks that are practically impossible for traditional computers.

This algorithm allows for the efficient factorization of large numbers, a process that underpins the security of public key systems, like the ECDSA used by Bitcoin.

If sufficiently powerful quantum computers are developed, they could access the private keys associated with Bitcoin addresses within hours or days, compromising the entire network's security.

Currently, the best quantum computers have about 1,000 qubits, but a successful attack on the cryptography of a single Bitcoin wallet would require between 13 million and 300 million qubits.

Companies like Microsoft, Google, and IBM are designing quantum computers with the goal of reaching 1 million qubits by 2027-2029, but even that milestone will not be enough to cause an immediate impact. The continuous advancement is undeniable and creates the need for preparation.

The Problem of Lost Bitcoins

In addition to the quantum threat, Bitcoin also faces a significant issue with lost Bitcoins.

The problem is that the Bitcoin protocol has already undergone updates to improve security, but only for new wallets. For a user who currently has Bitcoins in an old wallet, it would suffice to migrate their Bitcoins to a newer, more secure wallet. However, this cannot be done with lost Bitcoins, where users no longer have the password or with those belonging to deceased individuals.

It is estimated that about 1.6 million Bitcoins are out of circulation, a significant portion of which belongs to Satoshi Nakamoto, the creator of Bitcoin.

If quantum computing becomes viable to break the security level of these older wallets, there is a possibility that these Bitcoins could be recovered, which would have a significant impact on the wealth distribution within the network.

This issue raises not only technical concerns but also legal and economic ones.

Ongoing Solutions

The cryptocurrency community is already taking measures to protect Bitcoin against quantum attacks. One of the most promising solutions is the implementation of post-quantum signatures.

These signatures are designed to remain secure even in the face of challenges presented by quantum computers.

Unlike traditional signatures, which rely on systems vulnerable to quantum computing, post-quantum signatures use algorithms based on mathematical structures that quantum computers are still unable to break.

One of the most relevant proposals for Bitcoin's protection is BIP-360, which introduces a new type of address, the Pay to Quantum Resistant Hash (P2QRH).

This new system uses post-quantum signature schemes, such as algorithms based on networks, lattices, and supersingular curve hashes, which are resistant to quantum computer attacks.

Implementing this new address format will take time and consensus within the network, as it will affect how transactions are processed and recorded on the blockchain.

Examples of Implementation in Other Sectors

The adoption of post-quantum signatures and other quantum-resistant solutions is already underway in various sectors beyond Bitcoin.

In 2019, the National Institute of Standards and Technology (NIST) in the United States launched a competition to define the post-quantum algorithms that will be used in future cryptographic systems.

This initiative aims to create robust and efficient solutions that can be implemented not only in cryptocurrencies but also in secure communications, banking systems, and even in government sectors.

Some companies are already testing quantum solutions in areas like financial advisory, where post-quantum algorithms are used to protect sensitive financial transactions.

In the field of secure communications, major players like Google and Huawei are heavily investing in developing secure communication networks that use post-quantum cryptography, preparing for a scenario where quantum attacks may become a reality.

The defense industry, in particular, is using quantum algorithms to ensure that its infrastructures and critical data are immune to potential attacks.

Conclusion

While the impact of quantum computing on Bitcoin's security is still distant, the threat exists and grows with the advancement of technology.

The implementation of post-quantum signatures and the proposal of P2QRH addresses represents important steps to protect the cryptocurrency from future attacks.

The challenge lies in making this transition in a planned and coordinated manner, ensuring that all members of the Bitcoin network adopt these solutions in a timely manner.

The future of Bitcoin depends on the network's ability to adapt to the new quantum era. Bitcoin's resistance to quantum computing is not guaranteed, but the ongoing effort to strengthen network security, alongside the development of post-quantum cryptography, will help ensure its longevity and reliability in a world increasingly influenced by quantum computing.