**Quantum computing and blockchain technology**

Quantum computing has been on the increase for some time now but also trailing blockchain technology for obvious reasons. The new advancement of computing allows complex problems and equations to be solved exponentially. Indeed, there’re reports suggesting that, Quantum computing is rendering existing encryption standards outdated and threatening the security of blockchain technology. It’s not only crypto-based technology that would be at risk, institutions like banks, organizations and even countries deploying blockchain technology will also be affected.

We were told recently that, Google has made a quantum computing breakthrough which is called quantum supremacy. According to the report, Google used quantum computing to perform a calculation within three minutes that would take any powerful supercomputer 10,000 years to achieve. This could send panic to the blockchain followers that, all blockchain has achieved thus so far, could be wiped away overnight.

**What is Blockchains technology?**

A blockchain is a decentralized and distributed ledger consisting of records known as blocks that is used to record transactions across multiple networks. The blocks formed cannot be altered retroactively without altering all the subsequent blocks.

So, there is no third party or governing body, that can arbitrarily modify data in a blockchain, nor is there, a single point of failure from where the database could be destroyed or hacked. The security of a blockchain is guaranteed by its cryptographic features, and in the face of quantum computing, most blockchains in the industry are at risk.

**Quantum computing and cryptography**

Quantum computing is the area of study that uses the principles of quantum theory to develop computer technology. The quantum computing, applying the laws of quantum physics, could amass huge processing power via the ability to be in multiple states, and to perform multiple tasks simultaneously.

Much has been said on the topic of how quantum computers pose a threat to currently used asymmetric cryptography. Asymmetric cryptography is a public/private key pair generated in a way that the two keys have a mathematical relation between them. As we know, the private key is kept secret, while the public key is made public. This enables individuals to tender a verifiable digital signature (using their private key) that corresponds to the public key. The security of asymmetric cryptography is based on a mathematical model called a “one-way function”. This principle indicates that the public key can be easily derived from the private key but not vice-versa.

This encryption is adopted in the financial industry to prove integrity and authenticity of transactions.

**These theoretical threats have limits**

In practice, quantum computing poses only a marginal threat as the public-key cryptography, is made up of an elliptic curve digital signature algorithm (ECDSA). Quantum computing can only be used to crack the current standard which is RSA algorithms. However, if quantum computing is applied to encryption, the encryption gets harder and tighter to break the blockchain codes.

Another vital point is that, the likes of Google, IBM and a number of other technology giants developing quantum computing are likely not targeting to crack blockchain or bank-encryption. Attempting such will destroy the reputation of the tech giant.

I foresee the future of encryption being improved by quantum computing and blockchain leveraging on such improvement to get more wins.

**Next steps**

The blockchain businesses need to update its existing software to use an enhanced asymmetric cryptography – one-way cryptographic functions. This is hard to reverse using conventional or quantum computing. Until these post-quantum solutions are established, this emerging threats should be taken seriously and all adequate security measures put in place.

I like what the US National Institute of Standards and Technology (NIST) is doing, gathering proposals for post-quantum cryptography and encryption. The aim is to have what could operate and not be broken even with larger quantum computing technology.

**Closing thought**

Quantum computers may pose a challenge to the security of the blockchain technology and the target may be cryptocurrencies like Bitcoin. Presently, about 45% of the Bitcoins in circulation are vulnerable to any quantum attack due to poor security architecture of the companies handling such cryptocurrency transactions. If you have cryptocurrencies in a vulnerable wallet and believe that, the progress in quantum computing is more than what is being reported; then you need to move your coins to a more secure physical wallet address.