Public or Private? Blockchain Distinctions Are Falling Out of Fashion

For some, it simply means that innovations developed on a public blockchain powered by a cryptocurrency can be leveraged on a private blockchain used by enterprises, and vice versa.

As companies start to recognize the merits of public chains; as new technology enables different types of ledgers to communicate with each other; and as central banks consider issuing digital versions of their fiat currencies that could be used to settle trades in blockchain assets; nomenclature is evolving to fit the times.

Back in 2015, the industry needed to diverge into public and private spheres, Wolpert said.

"Pressuring businesses to move core operations to public chains is unnecessary; soon enough the lines between public and private will blur into a pragmatic and functional internet of value."

John Whelan, director of Banco Santander's Blockchain Lab, drew on the internet-intranet analogy, often used by cryptocurrency proponents to argue private blockchains will one day dissolve to insignificance.

"On the product level, I think we can expect to see continued cross-pollination of ideas and technologies between public and private blockchains, since there is a great deal of technical overlap between these two types of system," said Gideon Greenspan, CEO of MultiChain, a startup that helps organizations build and deploy blockchains.

Confidentiality and governance requirements are completely different for public and private chains, he added.

"The closest I've seen is using a public chain to notarize a hash representing the state of a private chain, and this can make sense for extra security, but I don't really think you can call it 'convergence.'".

Svensson also pointed to identity as another area where public and private chain boundaries could theoretically be crossed, since identity on a blockchain is always protected by a private key.

Still, a prerequisite for full-fledged convergence of public and private chains would be the development of fiat cash on distributed ledgers, or so many seem to agree.