But there is a difference. Blockchains are one way to implement distributed ledgers but not all distributed ledgers are based on blockchains, and perhaps this distinction has not received much investigation and explanation. The devil is in the technical detail, but at a high level there is this quick guide on the correct terms to use.
These matters might get a bit more focus now as a result of a recent spat over some news articles that related to R3. One article carried the headline “R3 turns its back on blockchain?” and was driven by an R3 presentation that noted it did not actually use a blockchain in its Corda platform. That came as a surprise to many, and the news articles (as well as a rebuttal from R3’s PR company) stirred up a fair amount of frothy discussion on the interweb.
As far as I can tell, R3 has never actually said that Corda is blockchain-based. Way back in September 2015, when Corda was still being conceived, R3 techie Tim Swanson pointed towards its underlying technology in a blog post that stated “It also bears mentioning that the root layer may or may not even be a chain of hashed blocks.”
Then, when Corda was introduced in April 2016, a lengthy blog post written by R3 top techie Richard Brown discussed how Corda is similar in some ways to a blockchain, but it doesn’t tick all the boxes. Indeed, another buried quote stated: “we are not building a blockchain.”
R3’s position re. its technology aside, more clarity on blockchain versus distributed ledger technology is probably needed — and we’ll see what the WSBA can do to help with that.