[VIDEO] Brief Overview of the Mini-Blockchain Scheme

[bitfreak!]

I'm always receiving messages from people who have trouble properly understanding my mini-blockchain scheme so I thought it would be a good idea to make a video which could provide a brief description and explanation of the mini-blockchain scheme and the advantages it offers. I would recommend reading through the mini-blockchain wiki for the full technical details but hopefully this video will help out a few people who can't be bothered reading through the wiki. Make sure you have annotations enabled because there are a few important notes that I forgot to mention in the video.

Link:
https://www.youtube.com/watch?v=gQsIEXZYQMQ

[polymium]

Do you have a list of projects using similar ideas?

I am working on a project that uses the concepts (see here), though no code or real details yet), but the project itself is much more than what you have described, only the "forget the chain" part is similar, using a merkle-tree to store valid snapshots of the database. (which database can store user accounts)

As far as I know ethereum is also similar.

Any other?

[bitfreak!]

Do you have a list of projects using similar ideas?

Well off the top of my head, I believe the MC2 guys are working on incorporating something like this into their coin. There is a project called MITOSYS which seems to be aiming for a system like Bitmessage but with the ability to function as a crypto-currency and not just a messaging service. There's also a relatively new project called NEX which seems to be some sort of fork of Nxt.

But honestly none of these projects are what I would like to see. I just want to see a plain implementation of the mini-blockchain scheme. A simple cryptocurrency implementation. MC2 is the closest thing to what I'd want to see but based on my discussions with tacotime it seems like they are working on an efficient blockchain pruning algorithm, which is completely different to the mini-blockchain scheme.

As far as I know ethereum is also similar.

I don't know much at all about Ethereum but it seems to be the complete opposite of the mini-blockchain scheme, like I mentioned in the video. I don't see how Ethereum could be taking a similar approach because the mini-blockchain scheme doesn't support scripts, and Ethereum is all about taking scripts to the extreme.

And your Polymium proposal sounds very much similar to Etherum with its claim to support "user-defined applications" so I don't see how you are going to be able to incorporate the mini-blockchain scheme into such a design. I would appreciate an explanation for how you believe it could be possible.

[polymium]

I believe the MC2 guys are working on incorporating something like this into their coin.

This looks interesting, the whitepaper is promising.

There is a project called MITOSYS

I don't see any actual product here, seems like just a bunch of ideas without any progress.

There's also a relatively new project called NEX which seems to be some sort of fork of Nxt.

This looks like just a barely tweaked version of Nextcoin, I don't think they will have any significant feature if Nxt doesn't have it.

it seems like they are working on an efficient blockchain pruning algorithm, which is completely different to the mini-blockchain scheme.

You mean they are working on dropping the old transactions with used outputs instead of maintaining the balance tree?

I don't know much at all about Ethereum but it seems to be the complete opposite of the mini-blockchain scheme, like I mentioned in the video.

Ok, I have to admit that I haven't watched the entire video, having read and understood your wiki already. But then it is not clear what exactly the mini-blockchain scheme covers in your interpretation. I thought the main idea is to be able to drop the old blocks by maintaining a hash-tree of the relevant, up-to-date data. Anything above that (scripting or other app layers) is just icing on the cake. I am not sure why you would be against such implementations?

And your Polymium proposal sounds very much similar to Etherum with its claim to support "user-defined applications" so I don't see how you are going to be able to incorporate the mini-blockchain scheme into such a design. I would appreciate an explanation for how you believe it could be possible.

Dropping the scripting layer and replacing it with a hard-wired coin script pretty much results in your scheme. Actually the script I mostly use for testing implements a very similar coin, so making that script the only valid one makes the system behave very-very similar to what you describe. (though I only started researching the already published suggestions after more-or-less coming up with the basics, but we pretty much arrived to the same conclusions in the main points) So instead of the rigid user-balance tree, the tree can store almost any kind of data, but it's managed very similarly. (This is also true for ethereum, the differences between that and my scheme start after this part)

[bitfreak!]

I tend to agree with your thoughts concerning the three projects I mentioned, MC2 is the most promising but it's probably a bad idea to get your hopes up. I should have also mentioned that I have a $20,000 bounty waiting for the first person to implement the mini-blockchain scheme. I have also been talking with the lead developer of "peershares" and he seems to be willing to offer another $30,000 bounty (more info here).

You mean they are working on dropping the old transactions with used outputs instead of maintaining the balance tree?

Yes exactly, it seems to be something very similar to the "ultimate blockchain compression" proposal.

Anything above that (scripting or other app layers) is just icing on the cake. I am not sure why you would be against such implementations?

I'm not against it, I just don't really see how it could work. If the old transactions are discarded then the only way to securely store scripts is in the account tree, but then that kind of defeats the whole purpose of the mini-blockchain, you might as well just use a normal blockchain. The whole advantage of the mini-blockchain scheme is that we can discard all transactions after a certain period of time, because the transactions are the bulkiest part of the entire system. Storing scripts in some sort of long-term fashion just takes us right back to square one. Watch the video and you should get a better understanding of why it cannot support scripts. Here's a quote from the wiki:

Script is not used within the mini-blockchain scheme. Since the account tree holds the final balance of all non-empty addresses and is not a continuous ledger of transactions like Bitcoin it's not possible to use scripts which must be solved at a later time because transactions in the mini-blockchain are discarded after a relatively small period of time (the length of the mini-blockchain cycle time). However, this is not really as much of a disadvantage as it may seem.

It is still possible to allow more complex types of transactions by defining special account types which support things such as a multi-signature transactions. By not utilizing script we get the advantage of making many aspects of the system exceptionally simpler and at the same we get an increased level of security because every type of possible transaction will be very well defined, eliminating the risk of an unforeseen script causing havoc on the network.

http://bitfreak.info/mbc-wiki/index.php?title=Transaction_Signing