This Chapter is about future of blockchain. We will mostly concern ourselves with technical functionality, as there is more discussion available. Finance and business also depend on these developments, although some are finance or business driven. In this Section, we concern ourselves mainly with quantum computing, with less flamboyant technical Section to follow.

In 2019, Google research unit (https://research.google/pubs/) published their breakthrough on quantum computing, using quanta in computer to multiply the computing speed compared to traditional binary systems (Arute et al. 2019). This has clear effect on the blockchain technologies, as cryptographical tools are heavily based on difficulty of solving the problem of decrypting messages. With quantum computing, it is at least theoretically possible to break the cryptography of encrypted messages. In the following, we discuss these developments.

As it stands, the present blockchain cryptography is the elliptic curve digital signature algorithm (ECDSA), which seems to be more easily hacked with quantum computing than other cryptographic schemes like RSA (https://en.wikipedia.org/wiki/RSA_(cryptosystem)). The quantum computers do not operate in bits but qubits. The more there are qubits, the faster the resulting quantum computing is. In September, IBM released news that it has built a 65 qubits quantum computer. There is a common belief that 1000 qubits would be enough to break blockchain’s ECDSA encryption, which creates challenges to current cryptography not only concerning blockchains but elsewhere on the Internet as well.

Another problem for blockchains concerning quantum computing, especially concerning Bitcoin, is the proof of work scheme. Quantum computing can generate a large amount of proof-of-works without considerable computing time, therefore enabling a large-scale malicious attack on the current chain of transactions. It can be noted that the same phenomena can be utilized for the advantage of electric voting systems because governments can obtain quantum computers and safeguard a blockchain system with hard-to-solve cryptographic functions.

It should also be noted that although developments in quantum computing are gaining momentum, the actual computers built are still few and they suffer from many technical difficulties in reaching their maximum theoretical computing speed. However, at least in five years quantum computing will influence the largest blockchains, as institutions who then possess quantum computers will have a clear advantage in use of blockchains, both considering cryptography and creating new blocks. This is a problem for current functionality of e.g., Bitcoin.

About the future of cryptocurrencies: https://www.europeanbusinessreview.com/what-is-the-future-of-blockchain-and-cryptocurrencies/

Industries potentially disrupted by blockchain: https://www.cbinsights.com/research/industries-disrupted-blockchain/

Predicting the future is difficult: https://aithority.com/guest-authors/blockchain-technology-in-the-future-7-predictions-for-2020/

For the future research on blockchains, see e.g.: Rossi, M., Mueller-Bloch, C., Thatcher, J. B., & Beck, R. (2019). Blockchain Research in Information Systems: Current Trends and an Inclusive Future Research Agenda. Journal of the Association for Information Systems, 20(9), 14.