My vision isn’t just around a single server but as a way for players to move their “progress” from SMP server to server, or to entirely different games or markets.  You play for a while and accumulate some “progress” and then turn around and buy ranks, items, or memberships on other servers or games when you want to move on.  The benefit being keeping “progress” in the form of Bitcoin and being able to purchase or donate to other servers without needed a credit card, etc.
 

A Bitcoin backed/based economy would be fantastic but there’s some specific reasons the first round of The Bit Mines wasn’t implement this way. It’s such a popularly requested implementation we’ll probably be working on it in the future.
 

The reasons I didn’t go this route, and thoughts on the subject

1. I don’t trust plugin code, and we’re talking about money here.  This is why I pulled all the calculations and payouts out of the game engine ENTIRELY (and ever off the same physical servers).  Minecraft in-general is too easy to exploit.
    

2. You CAN use /give and it won’t break, but you need to account for this a head of time.  Not only would players have their own bitcoin wallets, but the server would too.  You handle insufficient fund errors, etc at the layer that interacts with the bitcoin deamon.  I’ve already had to address this in my current deployment.  Additionally you have to ensure that in-game currency totals ALWAYS match actual back-end ledgers and this seems error proned (unless your in-game money is the only ledger – see item 1).
    

3. Player’s have money sitting in your system.  My implementation only risks my own money and ‘theoretical’ claims to the money.  Since Bitcoin vendors are a prime target for hacks it seemed unwise to risk player money like this for Minecraft.
    

4. Having the ability for players to give each other money in-game, (usable outside the game) also opens up the question of gambling.  Since online gambling is illegal for large portions of the population care needs to be taken on how Bitcoin integration is implemented.

Other routes I investigated to fit Bitcoin into Minecraft

1. Assign each block it’s own bitcoin address.  Money could be sent to specific blocks in the game world and users would get the funds transferred to their user address when they claim the block.  In this scenario each block would really have value and provides incentive to claim and control land.  Some areas of land could have greater value (or none at all), or anyone could send bitcoin to blocks in-game which is interesting.
    

2. Don’t actually put player money into a hosted wallet but allow for a payment system in-game.  The economy and user-interface would be updated to allow the user to issue payments and we’d process them during the in-game “trades”.
    

3. It would be great if mining in Minecraft could correspond to real hashing.  This isn’t feasible given the difficulty of hashing though.  Bitcoin mining is moving away from CPU/GPU implementations all together.  As a note I’m also a bitcoin miner (who uses FPGA setups, and who is also patiently waiting on the ASIC pre-orders).  You get almost nothing for using CPU/GPU based mining and anyone who has better hardware won’t make enough from Minecraft bitcoin hashing for it to be worthwhile (it would even be faster to just use a straight mining application without Minecraft running).  You might be able to get close using a mining pool paradigm but you’ll need a Minecraft server which can handle thousands of concurrent users..  This is a different topic and the subject of my original interest in developing against Minecraft, databases, and server to server communications plugins way back in alpha. :)

The First Round
The easiest way was to bring Bitcoin into Minecraft was to reward player actions, and block-churn. We can run a block change logger using mysql as the storage back-end.  I’ve written database based plugins a few times for Minecraft, but using an existing plugin has the advantage that it’s written and maintained by another group.  Also you aren’t logging all the changes twice this way (less load). We can also make the system work with all major logging plugins which is a big advantage.

The claim information is updated when the logging plugin updates using a series of triggers and stored procedures.  It’s best to approach it this way in-case the 3rd party logging software changes its database schema (or you change logging plugins) – You can just change the way you feed the updates into the back-end system.

The leader boards are generated using scripts that run against the database and then publish to one of the web servers. A financial server works against the database server and automatically interacts with the bitcoin deamon for handling of payouts.  This was important for me so that the process could can run automatically.
 

Past Challenges

• How to associate a bitcoin address to a specific Minecraft user account, since you only really know a player is the player from within Minecraft.

Resolution

• The user had to be able to set a bitcoin address from within the game.  I wrote a small plugin that handles the database call to store the information for use on the financial side.  The validity of the address gets checked during the payout process and not when the user sets it.  I’d like to change this in the future.

Current Challenges

• How to notify the user in-game that a claim is credited or what their current ‘multiplier’ for claims is?

Possible Solution

• I will probably start looking into Spout again as I’ve done server to client spout mods before.  I’ll have to look at both synchronous and asynchronous updates as I have concerns with both implementations.
• Current Partial Solution:  Use of the leader boards on the website which get updated about every 2 minutes.

I hope to see others adding Bitcoin features on their servers and other games too.
Cheers!

Built against:
craftbukkit-1.3.2-R2.0
worldedit-5.4.2

Package contents
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src – plugin source
InstanceJanitor.jar (0.4 binary)
worldedit-5.4.2.zip (WorldEdit plugin)
runtime – sample server deployment
Go to 14 67 244 and enjoy the demo!
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=–=

Download Here!

Change Log:
/say command works again
Updated sound engine and added minecart sound effects
Various other sound effect changes
A few tweaks to the witch mob

Change List:

Tweaks to the Wither
Carrots are now carrot, and added new food item
Tweaks to a couple of item sprites
Leather armor now has a non-dyed layer
Superflat customization options
Pigs are now able to jump when players ride on them
Added /clear command to empty the inventory
Evil mobs are now a little bit more fearless in hard difficulty
Various bug fixes