MultiBit

[Ryland R. Taylor-Almanza]

You ever consider doing a mobile version of Multibit? Specifically iOS.

Can iphones run java programs?

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[bitcoinspot.nl]

This is f*ing great you guys!
Now i can finally create a donate button so that people can donate bitcoins to me in 1 click.
VERY VERY nice.

If you put a donate button on your site, i will be very pleased to clickit and send you some coins!

[jim618]

Thanks bitcoinspot.nl ! 
I will put a donate button/ QR code on the multibit.org site - cheers.
I am hoping that the other desktop bitcoin clients will reuse what we have done so that it becomes the standard way for browsers to show their bitcoin payment requests.

@gnar1ta$, Ryland
Unfortunately on a 'bought from the store' iOS device they cannot run Java.
In a similar way to Apple not allowing Flash on their browser, they do not want people running a Java virtual machine.
There is no technical reason for this as I am pretty sure jailbroken phones can run Java but the average user is not going to do this.

I am hoping that BitPak will be able to progress their code and then open source it so that there will be at least one native iOS bitcoin client for iPhones and iPads.   Bitcoin on iOS is quite frustrating at the moment.   Currently I have an iPhone 5 but will be changing it soon for an Android device - mainly because the bitcoin development is much better on Android than iOS.

[jim618]

I have put a "Please donate to multibit.org" combination bitcoin link+swatch on the http://multibit.org website should anyone be feeling generous.

Any BTC donated will get used as seed money for the MultiBit Merchandise venture Gary and I will be setting up later on this year.

This will be an online 'Bitcoin Shop' to:
1) Test out our MultiBit Merchant software and iron out any bugs. (Eat your own dogfood!)
2) Sell some 'soft marketing' Bitcoin merchandise to spread the word about Bitcoin.

[bitcoinspot.nl]

Promise makes good, just sent you the 0.2 bitcoins
I like the swatch thing, gonna be puttin it on my site also.

Three questions:
- will this optionl be included in the new 0.3 version ?
- My girlfriend said: wouldnt it be nice, that when you click on it, it asks you for the amount, instead of filling it in for you ?
- will you be getting in touch with the other bitcoin-clients programmers to try and make this some kind of a standard ?

greetz,

[jim618]

Thanks for the donation !

RE: your questions.

1) Yes - it will be in the 0.3.0 release.  

2) You can change any of the information (address, label, amount) once the bitcoin link has been read and entered into the Send form.   It works similar to how swatches (or bitcoin link text) are pasted into the form.   You could have an intermediate/ interstitial form where the user can change the amount (or anything else) but there isn't really a need to do that as you can change it on the form.  

You can also omit the amount (i.e. have a swatch/ link with just the label and address) if you prefer to leave it out.


3) The format of the link is identical to bitcoin URIs and is pretty standard.  I think all the clients - including the mobile ones - all use the same format for address/ amount/ label.    Once we sort out any bugs with how the protocol handlers work I am going to write a Google doc to make it easier for the other clients to support it.   I know the Satoshi client you can paste a text bitcoin URI onto it and it reads it and fills out the Send form.  To extend it to work for browser protocol handlers would be a bit of work but I am hoping with a bit of assistance from us that they will want to implement it.

Of course if all the bitcoin clients can read the same format it makes the job of website designers far easier as they just have the one bitcoin link format to put on their pages.

[jim618]

I have started on the improvements to MultiBit for exporting and then re-importing private keys as that has been a popular request.   Please have a look at the wiki:

https://github.com/jim618/multibit/wiki/Export-and-limited-import-of-private-keys

Let me know if you have any comments.


Initially I am focusing on a flat file with all the private keys but once that is working I think I will extend it to a 'output a single key to swatch' approach.   I like freemoney's suggestion to add the date of first transaction to the key swatch to enable automatic update of a wallet from a key swatch. (With MultiBit you need the date of first transaction for the key so that you don't have to replay the *whole* 3 years of blockchain).

The format of the MultiBit key file is intentionally as simple as possible so that you could handcraft one if you want to import keys from the Satoshi client or wherever.

Edit: wiki updated significantly after discussion on bitcoinj mailing list

[freemoney458]

Hi Jim,

after reading the wiki about the private key file, I still had one question.

Will the encryption of the private key file be optional?
If encryption is mandatory, your efforts to make it human editable are in vain.
So I guess, encryption will be optional or possible to activate after exporting / importing the keys.

Am I right?

[damnek]

This new version is awesome! I'm proud to have contributed a translation to such a revolutionary piece of software.

Two minor things that I noticed:
1) When I click on a URI while I already have MultiBit open, it will display the splash screen again. I think it would be better to skip that.
2) The input field for transaction fees is too small.

Good luck with your project!

[jim618]

@freemoney - Yes you are right that the user needs to be able to export/ import plain text files.

On the 'export keys' screen, I plan to have a radio button so that when the user does the private key export they can choose from
  o  Do not password protect key file.
  o  Password protect key file.
          Password           ___________
          Repeat password ___________

          <Show strength of password>

If they choose 'Do not password protect key file' I will put up a nag message saying that they really need to keep their keys safe!

Similarly on 'import keys' users will be able to import a plain text file or a password protected key file.



@damnek
Well thank you for your translation work!   MultiBit is gradually becoming more useful as each piece of functionality goes in.

RE: Splash screen.   Yes - The splash screen is intrusive so I will get rid of it when you already have MultiBit open.
RE: Transaction fee field width.   I will fix the width of this field.   I presume that is on either Windows ot Linux as I have not seen it on the Mac.

[jim618]

I have been doing some tidying up this week on MultiBit so that:

+ You can specify what you want to happen when bitcoin links are clicked in a browser.
+ You can change the font and point size of the application (useful for bigger screens and to get the best-looking font for your language).

Here are a couple of screen shots in the rather jaunty Ubuntu Purisa font:

http://multibit.org/postImages/ubuntu-receive-purisa.png
http://multibit.org/postImages/ubuntu-preferences-purisa.png

(Of course you can have more sober fonts if you want . . .)

There is also one level of undo on the Preferences screen for if you accidentally choose Chinese or Russian and then realise you cannot read those languages.  Just press 'Undo last changes'.  (The undo button lags in changing language+font so you can still read it)


There are also various minor UI tidy ups e.g fix of transaction fee field width on Linux, ENTER commits wallet description change etc.
Everything will appear in a beta release which will be Sunday/Monday or so.

[conspirosphere.tk]

Any way to import a wallet from the official client in Multibit?

[jim618]

The next piece of work I am going to do (as in start next week) is to do export/ import of private keys.

It is primarily so that you can get your private keys out of MultiBit for backup but you will also be able to get other keys in (with a bit handcrafting of an ASCII file).

It won't be a seamless import of the wallet.dat or anything but is the start of opening things up.
It will also mean you will be able to start swopping private keys in and out of MultiBit and things like a blockchain.info wallet etc.

[jim618]

There is a new release of MultiBit available at:

http://multibit.org


Enhancements
+  Bitcoin protocol handler registered and calls dealt with
    (i.e. can now click on bitcoin links in browser and MultiBit opens)
+  Can now specify font and point size for application

Bug fixes
+  Issue 4 - Can now press enter to navigate out of wallet description
+  Transaction fee field width fixed for Linux

[jim618]

I just wanted to mention that Gary Rowe has been doing some sterling behind the scenes work and there is now a MultiBit continuous integration machine.

It is actually the main bitcoinj machine but he has added builds for:
+ MultiBit
+ MultiBitMerchant

It is at:
   http://ci.bitcoinj.org

There is all sorts of interesting information available, including:
+ what commits have gone in, with their comments
+ if you want to try the bleeding edge code, there is a Modules directory for each project with the build artifacts.


For instance, MultiBit is currently building 0.3.0beta2 (not yet released to the public) and the build artifacts are at:
   http://ci.bitcoinj.org/job/MultiBit-v0.3/org.multibit$multibit/

The multibit-0.3.0-beta2-exe.jar there is a work-in-progress version of what eventually gets packaged up into the installer, DMG etc and can be run with:
   java -jar multibit-0.3.0-beta2-exe.jar

Note "bleeding edge" means :
"This code is built automatically whenever someone checks in their code changes.  
It may very well explode dramatically with blobs of molten aluminium flying out the screen".  

I exaggerate for effect but I hope it is clear what this means.   :-)

[HanSolo]

Does Multibit independently verify the transactions of every block it accepts?

(I thought BitcoinJ, on which Multibit is based, needed to be attached to a trusted full node... wondering if Multibit shares or works around that limitation.)

[jim618]

Hi HanSolo,

You are correct, MultiBit uses bitcoinj for its access to the bitcoin network.   By default, on startup it connects to 4 peers that are found by a DNS lookup.   The peers will be full miner nodes.

MultiBit/ bitcoinj does basic syntactic checking of the blocks but the main protection from malicious blocks are the multiple peers and the blockchain itself.   It does not recalculate that the nonce is valid. The nonce is checked to be below the difficulty (as specified by this and preceeding blocks).

Imagine a situation where an instance of MultiBit is connected to honest nodes A, B, C and a malicious node M.
M can send it a syntactically valid block with a valid nonce containing, well, lies and MultiBit will initially accept the block and add it to its local copy of the blockchain.
When any of A, B, C send it an honest block it will then fork its local copy of the blockchain and maintain the two forks until the next block.
Assuming M cannot solve for blocks faster than the rest of the network then when the next honest block appears MultiBit will add the block onto the honest chain which then becomes the main chain.   It will then do a reorg and discard anything in the malicious block.

From the users point of view, they would see (unbeknown to them) malicious transactions with one confirm, which would then disappear when the honest fork reasserted itself.

Other more difficult attacks to pull off:
If an attacker could get a copy of MultiBit to connect to 4 malicious nodes it would be able to get its lies accepted as it would be able to convince MultiBit that its malicious version of the blockchain was the real thing.    I think that would involve either control of the DNS seed hosts or packet level control of the network the MultiBit is connected to.

(Note: for completeness I should add: you can actually get MultiBit to connect to a single node if you want - parameter 'singleNodeConnection=<machine name | IP address>' but obviously you want to either control that miner node or have some other reason to trust it)

[bitcoinspot.nl]

Maybe offtopic, but i want to request some extra options If this is not the place, please let me know.

I want to use multibit in a local shop and i would really like to:
a: have the option to enter an email-address and email the qrcode and text to the email-address on the click of a button
b: have the option to show the swatch in fullscreen (or just enlarged)

i made a little artistic impression of how it could look like - http://www.bitcoinspot.nl/tmp/swatch.jpg

Some extra options that would also be great:
a: Have the option to click something like a "create transaction" button so that:
- a new address is created automatically
-  i can monitor my open transactions, not just the running or completed.
b: Have the option to run miltibit on a central computer and access multibit trough a web-interface.
  (so that i can run it on my server and let my staff run around with i-pad's or smartphones)

Ok thats it for now

thanks for the good work!

[jim618]

We now have a Hungarian translation of MultiBit.
Thanks to Gábriel Németh of http://bitcoin.hu for the translation.

Screen shot:
http://multibit.org/postImages/hungarian.png

This will appear in the next beta, which should be Sunday or Monday.


I have also tweaked the multibit.org website so that in the 'Features' bar it links directly to the http://translate.multibit.org site for the languages.

[jim618]

@bitcoinspot.nl

Thanks for your post - yes putting feature requests here is good.   I am interested in seeing what people feel would be useful functionality to add.

I was planning to rework the 'swatch panel' a bit I must admit to make it a bit more flexible.
One of the things I was going to do was have a little combo box so that the user could choose:

Display as: swatch
                QR code
                <other options>

If they chose 'QR code' the QR code would fill the whole of the panel.
With something like your "make big" button that would then be big enough for a customer to scan with their phone.

I like your idea to be able to email of the swatch + text to someone from within MultiBit.   There would be more configuration to set up but it would be a nice feature yes.   

I did not quite understand your 'create transaction' button.   In what way would that be different from the 'Create address' button ?   (I just do not understand what your particular usage is).

RE: MultiBit as a web server.   It is a good idea but another team member - Gary Rowe - is busy behind the scenes creating MultiBitMerchant, which will be our web offering with a catalog, shopping cart etc.    Rather than duplicating effort in adding web capability to MultiBit I think it will be MultiBitMerchant that you will be looking at in the future.

That will be very interesting to see how your experience with bitcoins in a local shop progresses.   Make sure you let everyone know what happens!