This chapter aims to provide an introduction to various challenges that need to be addressed before blockchains can become mainstream technology. Even though various use cases and proof of concept systems have been developed and the technology works well for many of the scenarios, there still is a need to address some fundamental limitations that are present in blockchains in order to make this technology more adaptable.
At the top of the list of these issues comes scalability and then privacy. Both of these are important limitations to address, especially as blockchains are envisioned to be used in privacy-demanding industries too. There are specific requirements around confidentiality of transactions in finance, law and health, whereas scalability is generally a concern where blockchains do not meet the adequate performance levels expected by the users. These two issues are becoming inhibiting factors toward blockchain technology's wider acceptance...