I do not mind people being skeptical but sometimes it can seem disingenuous. I don't think Gavin was trying to be disingenuous but he was a little bit considering he was jumping to conclusions on assumptions and dubious subjective opinion.

It's fair to ask for what my previous experience is. It's not fair to say my project is an automatic failure because of my previous experience. You may wish to only donate to projects run by 50 year old experienced cryptographers and that is OK if you want that. Equally, a younger brain can yield much more interesting and innovative results. The problem with people with "experience" is sometimes this experience is full of old ideas and habits. I hope my progress on cbitcoin thus far has been some indicator to my ability. I'm just looking forward to completing it so I can really demonstrate what I can do.

The focus should not all be on me either. I'm the project leader but not the only person who will be working on this project.

I guess I just need to get that logo sorted. Once I have a logo people will have to take me seriously.  


Time is nice. I would appreciate that.  The library is not rough around the edges; it's incomplete. It doesn't completely work, it has many problems... because it's incomplete. I'm working on it (help appreciated).


This is opinion. My opinion is that it makes much more sense to have the left number as incompatible releases and the right number as compatible releases (No confusion over "will this break my code" then). Maybe I should have had three numbers but I prefer to keep it simple. If this goes against convention, then good. I like breaking conventions. I'll signify alpha and beta releases by adding alpha-x or beta-x on the end (eg. cbitcoin 2.0 alpha-2).

The "software-people-other-than-myself-are-going-to-use" I've successfully completed are iPhone and Android apps which I've developed over a couple of years. Also I've done some web-development (See for example: http://www.thelibertyportal.com/#articles) and I'm currently also working on a facebook app (but that's not finished).

You can see the android apps here: https://play.google.com/store/apps/developer?id=Matthew+Mitchell&hl=en_GB
And the iOS apps: https://itunes.apple.com/sa/artist/matthew-mitchell/id398617356 (Open)

Re-implementing bitcoin is obviously a major challenge compared to mobile apps. That doesn't mean I cannot do this though. I'm getting there and I'm getting there at a reasonable pace.

I will implement the makefile. Others said they would help with that but since no one has I'll do it myself but I'll do that in my own time (I've got a long list of things to do).


So it's a good idea not to improve software? cbitcoin 1.0 was OK but it was limited. I changed my vision for the project into something much more advanced. I do not see why that should destroy confidence.

But if anyone does not trust me, then that's fine, just wait a while and I'll prove you wrong. If there is one good thing about being criticised, it is that it becomes so much better when you make it work. I know what that feels like.

That doesn't mean cbitcoin is non-compliant with the bitcoin protocol. So it is unfair to say:


cbitcoin is a bitcoin library and not a bitcoin client. It will give developers the ability to broadcast transactions and it is their responsibility to ensure the transactions are produced correctly. And this is false:


Not "will". The correct word is "can" but obviously there is little good reason why someone would want to create duff transactions.

I don't know either. All I know is that it is that way for whatever reason.

Well it looks like I'll be able to get a logo done for £60 (~$95) upfront for initial designs (minimum 10). I'll then be able to post the designs on here to receive feedback. After deciding on a good design, for another £60 (~$95) the logo will be adjusted and finalised.

So that will be a cost of £120 (~$190).

So now you are telling me that the coinbase maturity is not 100 (ie. 101 confirmations)?

I've read the code. The code is lying to me? It's changed?

Explain to me exactly how cbitcoin is non-compliant with the bitcoin protocol.

I've now added the RocketHub page: http://www.rockethub.com/projects/11976-cbitcoin-developing-bitcoin-s-future

While I'm looking to raise over $6000 ideally, I picked the more modest $2000 goal as I think that should be reachable. I'd be very grateful for any donations. Using RocketHub you can become a donor or business sponsor.

I've also contacted a designer in regards to the logo. I should hopefully have that sorted within a couple of weeks. That will be a small cost.

Also please share the project on as many websites pages as you can. That much is free to do.

If anyone wants to be listed as a donor or a business sponsor then you can email me and I can give a bitcoin address: http://cbitcoin.com/donors.html

Anyone who has already donated more than $15 in equivalent bitcoins can email me proof that they own addresses spent from in the donation transactions, if they want to be included in the list. You can do that by signing your information to be included on the list with a bitcoin address which acted as the source of the transaction. Email me questions if you need help.

The categories are:

Business Sponsor: For $1000 or more you can have your business logo and weblink listed on the contributors page and the homepage.
Gold Donor: For $500 or more you can have your personal name or business name with an optional weblink listed on the contributors page.
Silver Donor: For $150 or more you can have your personal name or business name with an optional weblink listed on the contributors page.
Bronze Donor: For $50 or more you can have your personal name or business name with an optional weblink listed on the contributors page.
Other Donor: For $15 or more you can have your personal name listed on the contributors page.

Yes I know that. I was ignoring everything else and using the number 0 to demonstrate the mathematics. Imagine a different number if you want.

The genesis coinbase is not added to the unspent output index in cbitcoin so it cannot be spent. I made a note about it here: https://github.com/MatthewLM/cbitcoin/blob/master/src/CBFullValidator.c#L780

I've followed the validation rules carefully but indeed something might be missed which is why testing is important and I'd like to get others to look through the code.

Yes and ShadowOfHarbringer was most likely speaking of the 120 confirmation requirement. The answer to the original question is therefore that cbitcoin will not have this 120 confirmation restriction since cbitcoin will not restrict what transactions you can produce and broadcast. You can use it to create any transactions you want. It doesn't mean all transactions will be accepted by the network and cbitcoin will include checks on received relayed transactions.

Don't worry, I have implemented it as 101 confirmations. Obviously the block with the coinbase is included as a confirmation and I meant 101 confirmations. I did spend some time staring at it to make sure I did implement it correctly. Others might want to check again: https://github.com/MatthewLM/cbitcoin/blob/7ff4abcff40221ac0eee7a32b12b4509ee4a9f56/src/CBFullValidator.c#L450.

If we have a coinbase in block 0, we see by my code that the coinbase can be spent at block 100 (100 - 0 == 100) which is at the maturity and 101 confirmations, therefore it is correct.

I didn't know about the 120 behaviour, though obviously that has nothing to do with the block validation code so I've not missed anything there.

I have the coinbase maturity set at 100 and not at 120.

I'm going to start posting issues on the repository. It would be a good place to look for anyone that wishes to contribute: https://github.com/MatthewLM/cbitcoin/issues?page=1&state=open

As well as reading the README of-course: https://github.com/MatthewLM/cbitcoin/blob/master/README.md#making-a-contribution

So the satsohi client doesn't allow you to make transactions from outputs just found, even when they have 6 confirmations???

I'll get the fundraiser page up probably tomorrow...

I've been working on a B-Tree implementation for indexing. If anyone would like to help, the deletion algorithm need finishing and testing: https://github.com/MatthewLM/cbitcoin/blob/master/src/CBAssociativeArray.c#L154

And I'm following this but I can figure it out in my head: http://www.scribd.com/doc/18210/B-TREE-TUTORIAL-PPT

cbitcoin is not a client, nor will it be. When it is finished you could use it to create your own client which follows any behaviour you'd like as long as it works with the protocol. The full node implementation will provide the block-chain validation and you will be able to register events for incoming transactions which match addresses as well as for when transactions are found in blocks I've not got to implementing any of that yet.

It's really hard selecting which funding platform to use. There are advantages and disadvantages to both platforms it seems. I don't like indiegogo's checkout system which annoys you about paypal... I think I'll use rockethub. Any ideas for rewards? There's not much I can do. I could create a "Contributors" webpage on cbitcoin.com with a "Financial Contributors" or "Sponsors" section where I can place people's and business names with website links, logos and/or bitcoin addresses.

Perhaps there could be gold/silver/bronze sponsorship?

I'm going to decide tomorrow. In the meantime I'm going to leave a poll up so people can give their opinion.

Well I'm undecided between http://www.rockethub.com/ and http://www.indiegogo.com/.

The fee structure is reasonably similar:

http://rockethub.com

Reached goal = 4%
Failed goal = 8%
Transaction fee = 4%

http://indiegogo.com

Reached goal = 4%
Failed goal = 9%
Transaction fee = 3%
Plus $25 bank transfer fee.

I personally like the interface of indiegogo more. What do others think?

And thank you too. 

It uses the same block-chain as bitcoin. At the moment it has code for the production netwok but I plan to add testnet support also and maybe more configurable features for new chains in the future as well.

The code should be cleaner, yes, and have more documentation. On top of that, the fact my code is a library will make it more useful than bitcoind, it will have fewer and more configurable dependencies and will hopefully be more efficient, but that is yet to be judged.

No it is not a fork, it is a complete re-implementation of bitcoin, in the C programming language, as a software library.

Well all together I've found these websites which provide the type of thing I'd want:

http://www.rockethub.com/ (Thanks jimbobway)
http://www.kickstarter.com/
http://www.crowdfunder.co.uk/
http://www.indiegogo.com/
http://www.chipin.com/
http://www.gofundme.com/

I'll have to carefully go through them all to determine what I want. If anyone has any comments about them, please post them.

Thanks for the suggestion, though whatever service I use, it should be suited for the fact I have a UK bank account. I'll take a further look at fiat methods of donations tomorrow.

I'm also looking for a suitable noSQL database for block-chain storage, so I'll hopefully sort that out tomorrow: http://stackoverflow.com/questions/13317443/an-alternative-to-leveldb-that-allows-you-to-read-a-subsection-of-the-data-recor But for now, I'm off to bed