There's more dimensions to that though. Can participants have identities? If yes, then you don't need proof-of-work, for instance but can have a distributed led

There's more dimensions to that though. Can participants have identities? If yes, then you don't need proof-of-work, for instance but can have a distributed ledgers with conventional algorithms for Byzantine agreement etc. Might be just my misinterpretation, but when I hear blockchain I usually just think of conventional totally trustless and identity-less protocols that necessarily require proof-of-work - which is a security level which is not needed for most applications.