Quantum computing refers to studies of once theoretical quantum computers that make direct use of superposed and entangled quantum bits (qubits) to perform operations on data. Conventional computers, on the other hand, encode data into binary digits (bits) each of which is always in one of two definite states (0 or 1). It is worth noting that a company called D-Wave System, Inc. claims to be the first company actually selling quantum computers, which was founded in 1999.

Advantages Of Quantum Computing

Quantum computers using qubits can store an enormous amount of information and use less energy doing so than the classical computer. Moreover, quantum computers may result in processors with neck-break speeds and bigger computing capacity through their efficient and quick problem-solving, attributes which are not practically feasible on classical computers. However, quantum computers are not intended to phase out the conventional computers but rather are expected to modernize the ways to solve complex problems that are beyond the capabilities of classical computers.

To realize both practical and theoretical influences of quantum computing, several national governments and military agencies are funding quantum computing research in an effort to develop quantum computers to support the ever growing technological needs of civilian, business, trade, environmental, and national security purposes, such as cryptanalysis.

Cryptocurrencies

Cryptocurrencies are digital assets created as a medium of exchange by the use of cryptography and blockchain technology to make transactions secure and to control the creation of additional units of the currency. They are peer-to-peer transferred and confirmed in a process called mining in which those who help verify transactions and solve mathematical problems are awarded with the digital currency. Cryptocurrencies can be classified as a subset of digital currencies and alternative currencies. Since the first decentralized digital currency, Bitcoin, was released in the year 2009, a large number of cryptocurrencies have been created which have currently earned an average of $84,598,576,179 in total market capitalization. As of the 11th of July 2017, there were more than 900 cryptocurrencies available over the internet. Trailing behind Bitcoin, which is currently the largest blockchain network by market capitalization, are Ethereum, Ripple, and Litecoin.

Onset Of Quantum Computers

Companies such as IBM have created functioning machines which make use of 5 qubit processors, to prove and demonstrate the reality of the theory now and in the future. This has hyped fear of it’s capability of disrupting standard cryptosystems previously considered secure against regular digital computers. Though still challenged by leading computer scientists, Canada’s D-Wave company also claims to have already built quantum computers.

Although The Economist claims that quantum computers might still take some time to build, it asserts that a 300-qubit quantum computer can have more possible states than the number of atoms in this universe. Nevertheless, quantum technologies will be a reality soon as said by Ilyas Khan, Co-Founder of Cambridge Quantum Computing.

Can Quantum Computing Suffocate Bitcoin?

Quantum computing may be detrimental to Bitcoins unless individuals never spend Bitcoins and just receive funds with an address for them to be safe since the hashing process protects the public-key used to create the address. However, spending the funds requires revealing the public key to the network and signing of the transaction with private keys. At that point, the individual’s funds may be at risk of attacks by new quantum computers since the elliptic curve algorithm used to generate the public key can be theoretically reversed by quantum computers to expose the private key and make it vulnerable for individuals balances to be hijacked and compromised. This attack may happen to those individuals who do not practice using Bitcoin addresses only once.

Potentially, quantum computing could use Grover’s algorithm in hashing to speed up quadratics, basically halving key lengths. This could be advantageous in Bitcoin mining for quickening the rate of finding solutions by miners using quantum computing. By doubling the length of the key, the effects of Grover’s algorithm can be lessened to maintain the same difficulty as before. However, block size limit controversy could emerge making it even more difficult to implement a hard fork, such as moving to more difficult hash algorithms. Considerable efforts have also been made to maintain the blockchain size although the blockchain is still enormous, so alterations that increase standard block sizes would not be desired.

To solve the issue of elliptic curve vulnerability in the current Bitcoin model, Vitalik Buterin Co-Founder of Ethereum and of Bitcoin magazine chose Lamport signatures. Other solutions have also been proposed in the bitcoin network, apart from new standards, to curb the threats of quantum computing. Adoption of systems that would suit the circumstances of the future will be welcomed if the current standard of Bitcoin is compromised. For now, Bitcoin addresses should only be used once to evade possible calamities that quantum computing could bring.

According to Bitcoin.com, Bitcoiners should not be wary about the effects of quantum computing on blockchain technology since, first, Satoshi Nakomoto knew about the possibility of stronger computer power that would be able to compromise encryption, and that’s why he built the protocol to endure attacks. Secondly, those that might possess the talent to attack the Bitcoin’s encryption would likely forgo the opportunity.

SHA-256 which underlies encryption protocol of Bitcoin is obstinately resistant to any attempt to interfere with it. It’s likely strong enough to endure violent onsets from even the most ferocious quantum computer attack. An article by bitcoinnotbombs.com said that SHA-256 is strong enough to withstand attacks.

The Quantum Resistant Ledger (QRL) project is a public blockchain ledger that was created to exclusively secure against quantum computing attacks. It is specially created and designed to use a form of post-quantum secure signature for transactions called XMSS unlike Bitcoin or Ethereum ledgers.

The QRL also uses a low power proof-of-stake (POS) algorithm which utilizes repetitive hash-chains and provably secure hash-based pseudo random number functions. The POS algorithm is designed to have zero reliance upon conventional signatures which are vulnerable to powerful QC and allows nodes to run on low power devices including personal computers, and passively earn income by staking.

Some computer scientists assert that quantum computing, which is fast approaching (if not already here) will cripple the encryption systems of Bitcoin and kill it. Andersen Cheng, Co-Founder of Post Quantum, a U.K. cyber security firm, claimed that quantum computing will interfere with the cryptography surrounding public and private keys of Bitcoin. Martin Tomlinson, a professor at the Security, Communications, and Networking Research Centre in Plymouth University, adds that quantum computers can calculate the private keys from the public keys at a go. By learning all the private keys, attackers would gain access to all available Bitcoins. However, Llew Claasen, executive director of the Bitcoin Foundation, defensively optimized many cryptographers already working on a solution to curb quantum computing disruption in the Bitcoin network. New quantum cryptography standards will need to be incorporated into the Bitcoin protocol.

Cryptocurrencies are remarkably and progressively gaining mainstream recognition. However, it is time for the cryptocurrency developer community to keep a close watch on the development of quantum computing and get armed with contingencies, in case what is feared does indeed becomes a reality.


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