[srdev]

My observation is this:

The "killer app" of Blockchains are the trustless nature of the system. In most practical application, allowing actors without a trust relationship to interact with the log is not a significant requirement of the system. Once you remove that requirement, there are technically superior approaches to maintaining a ledger.

[vocatus_gate]

That's why I've never understood all this talk about "private blockchains." Why? What's the point? We already have distributed database systems that are light years faster than blockchains. The ONLY benefits of a blockchain-based approach are censorship resistance and not having to trust the actors in the system. If you don't need either of those two benefits, then there are far better existing solutions for record keeping.

[svara]

As far as I've seen, the point is mainly PR. These private blockchains are usually not bitcoin-style proof of work chains, but would more accurately just be called distributed databases. For example, look at https://www.openchain.org/, "How does it work" section. A lot of altcoins actually are the same, with explicit "trusted nodes", such as Stellar (https://www.stellarcoin.org).

Happy to learn about any counterexamples and use-cases for those.

[PeterisP]

Private blockchains have a use case where you have a central authority coordinating many participants that don't trust each other - if the central authority periodically publishes the signed blockchain ledger/update, it enables "shared truth" that every participant can use, and each of them can verify that noone has "altered history", that particular constraints have been met, etc.

In essence, it can be used as a versioning + signing mechanism for a shared database that ensures authenticity and non-repudiation even in the absence of trust.

[rlpb]

> ...if the central authority periodically publishes the signed blockchain ledger/update, it enables "shared truth" that every participant can use, and each of them can verify that noone has "altered history", that particular constraints have been met, etc.

In other words, something like http://ledger-cli.org/ stored in a git repository with some input validation and signed commits would suffice.

Proponents call this "blockchain technology" because it sounds advanced. They can because nobody has a definition of what "blockchain technology" is. In my mind, if it could have been designed by any competent engineer prior to Bitcoin, then it isn't "blockchain technology". But that's just me.