Do quantum computers threaten Bitcoin? Will a quantum computer one day arrive and empty all wallets and mine away all Bitcoins through its superior computing power?
With Google claiming to have reached quantum supremacy, the technology of quantum computers may not be very far off.
The blockchain
- Public permission-less blockchain networks are decentralized, which allows disruption of a centralized player. This enables creating new business models.
- Public blockchains promise immutable records and security of transactions.
The BitcoinBitcoin1$ 26,169.900.18%-6.01%-15.89%details blockchain achieves its security objectives because today‘s computers have limited computing ability. This is because the current computing technology uses ’Bits‘, i.e. the smallest unit of storing information.
However, quantum computing, a technology currently in a research and development phase, doesn’t rely on ’Bits’. It uses ’Qubits’, i.e. ’Quantum Bits’. Qubits can hold a ’0′, a ’1′, and a superimposed state of both, all at the same time.
This creates a completely different computing paradigm, with significantly more computing power than today‘s classical computers.
Private key-public key data encryption
However, that could change with the quantum computer. Peter Shor had introduced a polynomial-time quantum algorithm in 1995, which we now call ’Shor‘s algorithm‘.
It dramatically demonstrated how the new algorithm requires a very less number of operations to solve a large prime factorization problem, compared to a classical algorithm. In effect, a powerful quantum computer running ’Shor‘s algorithm‘ could solve such a problem in a few days.
Compare this to hundreds of billions of years that classical computers would take to solve a similar problem!
In the future, quantum computers
Some cryptocurrencies have anticipated the threat from quantum computers early. They have worked on building quantum-resistant blockchain networks. A few examples are Quantum Resistant LedgerQuantum Resistant Ledger692$ 0.139618-2.34%-1.73%-33.26%details, Hcash, and IOTA.