6 ms·

Google announces bitcoinj: a bitcoin implementation in Java

117 points by nas 16y ago

nas 16y ago
From the bitcoin.org forum: "Google is pleased to announce the release of BitCoinJ, an implementation of the BitCoin system in Java. You can get it here under the Apache 2 license." I suspect this is maybe not Google the corporation but a Google employee using their 20% time. Edit: I could be wrong, according to the IRC chat, it is an "official" project: http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_pleased_to_announce_the_release_of/ http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_ple...
mcantelon 16y ago
Is this an official Google project? Would be interesting to see Google Market support Bitcoin...
- zrail 16y ago
  It looks like it might be someone's 20% project.
- mithaler 16y ago
  Dunno how much this means, but the Java package namespace is within com.google. http://bitcoinj.googlecode.com/svn/trunk/docs/index.html http://bitcoinj.googlecode.com/svn/trunk/docs/index.html
- cdibona 16y ago
  Nope, it's a 20% project of on of our engineers. Google has no intention that I know of going further.
  - mike_esspe 16y ago
    Around 300 mhash/sec coming to our bitcoin mining pool are from several Google's ips. Is it another 20% project? :)
    - 0x6763 16y ago
      A single ATI Radeon HD 5970 can do 600 mhash/sec. See https://en.bitcoin.it/wiki/Mining_hardware_comparison#AMD https://en.bitcoin.it/wiki/Mining_hardware_comparison#AMD
      - nas 16y ago
        He meant Ghash/sec. That's quite a few ATI cards. ;-)
cheez 16y ago
I highly doubt this is official.
rmc 16y ago
The only thing that makes this seem offical is that the email address of the coder is "hearn@google.com", which AFAIK is only available to google employees.
three14 16y ago
This comment is dead for some reason, but useful: 1 point by nas 52 minutes ago | link [dead] From the bitcoin.org forum: "Google is pleased to announce the release of BitCoinJ, an implementation of the BitCoin system in Java. You can get it here under the Apache 2 license." I suspect this is maybe not Google the corporation but a Google employee using their 20% time. Edit: I could be wrong, according to the IRC chat, it is an "official" project: http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_pleased_to_announce_the_release_of/ http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_ple...
- naner 16y ago
  Chris DiBona replied below that it is just a 20% project.
  - kingkilr 16y ago
    You can tell because it doesn't have the Google label.
Tichy 16y ago
A way to use BitCoin on AppEngine would be useful.
- sgornick 16y ago
  Here are two Bitcoin sites that run on App Engine (though the Bitcoin wallet is on an EC2 instance): https://www.clearcoin.com/ https://www.clearcoin.com/ http://freebitcoins.appspot.com/ http://freebitcoins.appspot.com/ - http://python.witcoin.com/p/152/Python-and-Bitcoin http://python.witcoin.com/p/152/Python-and-Bitcoin
  - Tichy 16y ago
    I knew there are bitcoin app engine projects. It just would be nice to host everything including the wallet on AppEngine. Since money is involved, would be nice to not have too much administrator responsibility.
sp332 16y ago
The mechanism in the BitCoin network for making sure that not too many bitcoins are being made is to adapt the difficulty of making a new BitCoin according to the average processing power available to the entire network over the last 72 (?) hours. If Amazon or Google just dumped tens of thousands of nodes into the BitCoin network for a couple days, they could conceivably make more BitCoins than are "supposed" to be made, and own most of the currency for themselves. The artificial scarcity might drive up the price, or everyone else might just get bored and leave.
- kiba 16y ago
  Wrong. It's every 2100 blocks. The difficulty adjust so that the rate of bitcoin generation is always 300 bitcoin per hours. Also, it's not possible to generate more than 21 million bitcoin. Last time I heard, every 27 days, the hashrate of the network double, so it become more expensive for big dudes to own more than half of the hashing power of the network. Remember, the bulk of the computation machinery are ATI 5870 GPU farms, which are better than almost all the GPU out there for hashing. Amazon doesn't have these GPUs, and I don't know if Google possess a GPU farm. Read the FAQ at https://en.bitcoin.it/wiki/FAQ https://en.bitcoin.it/wiki/FAQ
  - kiba 16y ago
    Actually, the difficulty adjustment is 2016 blocks, not 2100 blocks. Sorry for the inaccuracy. The GPU farms are actually ATI 5970, not 5870.
  - deleted 16y ago
    [deleted]
  - tybris 16y ago
    It's funny that people are adopting BitCoin without any compelling evidence that it is safe. All alarm bells should go off when you hear "security without trust". I'm sure that if BitCoin will be taken seriously, Bruce Scheier will be happy to cause the first decentralized currency crash. There are many things you can do to rip apart a peer-to-peer network. You start by generating a few million identities. Next, you start manipulating the peer sampling mechanisms to surround nodes with evil peers and create groups of evil peers ready to acknowledge transactions. Finally, you can convince surrounded nodes of pretty much anything (e.g., that the network is far smaller and younger than it actually is) unless they consult a trusted authority claiming otherwise. Of course, if you had a trusted authority you wouldn't have to go through all this trouble and you could just let it sign a bunch of coins or even handle the full transactions. It would be just like every other currency, and now you know why. By the way, anyone can rent a cheap, on-demand GPU farm from Amazon: http://aws.amazon.com/ec2/hpc-applications/ http://aws.amazon.com/ec2/hpc-applications/
geuis 16y ago
Isn't the full block chain required? When your by client connects to peers, I thought it needed the full chain for verification?
- nas 16y ago
  I'm not sure but a Merkle tree is used so that the amount of data downloaded by a pure client is much smaller than what a full bitcoin node needs to download. This Java implementation would be well suited to an Android phone.
pilif 16y ago
seeing this packaged into a embeddable library really makes me want to do something like flattr but just using bitcoins (and not taking a cut. this would be just for fun) bitcoins are essentially free to transfer in any amount, so you could easily share 100% of what users are willing to contribute. Also, this would allow the service to instantly transfer a percentage of whatever a user has set aside, or even queue transfers up until coins are available. I really want to look into this now.
- acous 16y ago
  I would like to subscribe to the verbose version of your newsletter :) That sounds very interesting.
- joelthelion 16y ago
  > seeing this packaged into a embeddable library really makes me want to do something like flattr but just using bitcoins (and not taking a cut. this would be just for fun) Please, please do. I love the flattr idea, but it would need a lot more donors to have a significant effect. And it turns out most donors aren't ready to use a service that takes 10% of their donations. The same idea for free or almost, which could be implemented with bitcoins to avoid transaction fees, could be a huge success. And I'd donate to its creator :)
- sgornick 16y ago
  You mean something just like: http://www.YouTipIt.org http://www.YouTipIt.org ? (add a tip badge on your site and accept bitcoins) Here's a site with a YouTipIt badge: http://www.BitcoinMiner.com http://www.BitcoinMiner.com YouTipIt's fee is 0.01 BTC per tip, subtracted from the tip amount. ----- There's also a Hacker News / Reddit / Digg type of site, where you pay bitcoins to post, vote, and reply. But then you earn from anyone who subsequently votes or replies to your contributions. It's live now: http://www.witcoin.com http://www.witcoin.com
  - khafra 16y ago
    Witcoin is fascinating; thanks for the link. But it seems like it could make trolls very rich.
donpdonp 16y ago
The author explains in the bitcoin forum that the library is his 20% project. from http://www.bitcoin.org/smf/index.php?topic=4236.0 http://www.bitcoin.org/smf/index.php?topic=4236.0 "Google staff have the ability to spend ~20% of their time on projects that interest them ... standard process for open sourcing our code ... checked by our lawyers for things like trademark/export compliance... This is why the code has our copyright at the top. This is not "official" in that it does not reflect some vast corporate master plan, we are not about to start accepting BitCoins for AdWords, we have not just dropped 200GHash/sec into the network and we are not going to fork the block chain (to mention just a few of the theories I've seen floating around)."
sgornick 16y ago
A good discussion about Bitcoin from about a month ago: http://news.ycombinator.com/item?id=2200705 http://news.ycombinator.com/item?id=2200705
mkramlich 16y ago
The Google connection is interesting. Because Bitcoin's greatest weakness is that the integrity of the system can be subverted by a malevolent participant who has enough computing nodes to make up the majority of computing power. Not that I'm saying Google would do this. Or that Google couldn't do this if they just used the main C++ implementation. It was just an interesting coincidence because when one thinks of entities that might have massive computing power at their disposal, things like various major national governments (the US NSA, China, etc.), or companies like Google and Amazon, come to mind.

117 points by nas 16y ago

nas 16y ago

From the bitcoin.org forum: "Google is pleased to announce the release of BitCoinJ, an implementation of the BitCoin system in Java. You can get it here under the Apache 2 license." I suspect this is maybe not Google the corporation but a Google employee using their 20% time. Edit: I could be wrong, according to the IRC chat, it is an "official" project: http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_pleased_to_announce_the_release_of/ http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_ple...

mcantelon 16y ago

Is this an official Google project? Would be interesting to see Google Market support Bitcoin...

zrail 16y ago
It looks like it might be someone's 20% project.
mithaler 16y ago
Dunno how much this means, but the Java package namespace is within com.google. http://bitcoinj.googlecode.com/svn/trunk/docs/index.html http://bitcoinj.googlecode.com/svn/trunk/docs/index.html
cdibona 16y ago
Nope, it's a 20% project of on of our engineers. Google has no intention that I know of going further.
- mike_esspe 16y ago
  Around 300 mhash/sec coming to our bitcoin mining pool are from several Google's ips. Is it another 20% project? :)
  - 0x6763 16y ago
    A single ATI Radeon HD 5970 can do 600 mhash/sec. See https://en.bitcoin.it/wiki/Mining_hardware_comparison#AMD https://en.bitcoin.it/wiki/Mining_hardware_comparison#AMD
    - nas 16y ago
      He meant Ghash/sec. That's quite a few ATI cards. ;-)

cheez 16y ago

I highly doubt this is official.

rmc 16y ago

The only thing that makes this seem offical is that the email address of the coder is "hearn@google.com", which AFAIK is only available to google employees.

three14 16y ago

This comment is dead for some reason, but useful: 1 point by nas 52 minutes ago | link [dead] From the bitcoin.org forum: "Google is pleased to announce the release of BitCoinJ, an implementation of the BitCoin system in Java. You can get it here under the Apache 2 license." I suspect this is maybe not Google the corporation but a Google employee using their 20% time. Edit: I could be wrong, according to the IRC chat, it is an "official" project: http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_pleased_to_announce_the_release_of/ http://www.reddit.com/r/Bitcoin/comments/fyzhk/google_is_ple...

naner 16y ago
Chris DiBona replied below that it is just a 20% project.
- kingkilr 16y ago
  You can tell because it doesn't have the Google label.

Tichy 16y ago

A way to use BitCoin on AppEngine would be useful.

sgornick 16y ago
Here are two Bitcoin sites that run on App Engine (though the Bitcoin wallet is on an EC2 instance): https://www.clearcoin.com/ https://www.clearcoin.com/ http://freebitcoins.appspot.com/ http://freebitcoins.appspot.com/ - http://python.witcoin.com/p/152/Python-and-Bitcoin http://python.witcoin.com/p/152/Python-and-Bitcoin
- Tichy 16y ago
  I knew there are bitcoin app engine projects. It just would be nice to host everything including the wallet on AppEngine. Since money is involved, would be nice to not have too much administrator responsibility.

sp332 16y ago

The mechanism in the BitCoin network for making sure that not too many bitcoins are being made is to adapt the difficulty of making a new BitCoin according to the average processing power available to the entire network over the last 72 (?) hours. If Amazon or Google just dumped tens of thousands of nodes into the BitCoin network for a couple days, they could conceivably make more BitCoins than are "supposed" to be made, and own most of the currency for themselves. The artificial scarcity might drive up the price, or everyone else might just get bored and leave.

kiba 16y ago
Wrong. It's every 2100 blocks. The difficulty adjust so that the rate of bitcoin generation is always 300 bitcoin per hours. Also, it's not possible to generate more than 21 million bitcoin. Last time I heard, every 27 days, the hashrate of the network double, so it become more expensive for big dudes to own more than half of the hashing power of the network. Remember, the bulk of the computation machinery are ATI 5870 GPU farms, which are better than almost all the GPU out there for hashing. Amazon doesn't have these GPUs, and I don't know if Google possess a GPU farm. Read the FAQ at https://en.bitcoin.it/wiki/FAQ https://en.bitcoin.it/wiki/FAQ
- kiba 16y ago
  Actually, the difficulty adjustment is 2016 blocks, not 2100 blocks. Sorry for the inaccuracy. The GPU farms are actually ATI 5970, not 5870.
- deleted 16y ago
  [deleted]
- tybris 16y ago
  It's funny that people are adopting BitCoin without any compelling evidence that it is safe. All alarm bells should go off when you hear "security without trust". I'm sure that if BitCoin will be taken seriously, Bruce Scheier will be happy to cause the first decentralized currency crash. There are many things you can do to rip apart a peer-to-peer network. You start by generating a few million identities. Next, you start manipulating the peer sampling mechanisms to surround nodes with evil peers and create groups of evil peers ready to acknowledge transactions. Finally, you can convince surrounded nodes of pretty much anything (e.g., that the network is far smaller and younger than it actually is) unless they consult a trusted authority claiming otherwise. Of course, if you had a trusted authority you wouldn't have to go through all this trouble and you could just let it sign a bunch of coins or even handle the full transactions. It would be just like every other currency, and now you know why. By the way, anyone can rent a cheap, on-demand GPU farm from Amazon: http://aws.amazon.com/ec2/hpc-applications/ http://aws.amazon.com/ec2/hpc-applications/

geuis 16y ago

Isn't the full block chain required? When your by client connects to peers, I thought it needed the full chain for verification?

nas 16y ago
I'm not sure but a Merkle tree is used so that the amount of data downloaded by a pure client is much smaller than what a full bitcoin node needs to download. This Java implementation would be well suited to an Android phone.

pilif 16y ago

seeing this packaged into a embeddable library really makes me want to do something like flattr but just using bitcoins (and not taking a cut. this would be just for fun) bitcoins are essentially free to transfer in any amount, so you could easily share 100% of what users are willing to contribute. Also, this would allow the service to instantly transfer a percentage of whatever a user has set aside, or even queue transfers up until coins are available. I really want to look into this now.

acous 16y ago
I would like to subscribe to the verbose version of your newsletter :) That sounds very interesting.
joelthelion 16y ago
> seeing this packaged into a embeddable library really makes me want to do something like flattr but just using bitcoins (and not taking a cut. this would be just for fun) Please, please do. I love the flattr idea, but it would need a lot more donors to have a significant effect. And it turns out most donors aren't ready to use a service that takes 10% of their donations. The same idea for free or almost, which could be implemented with bitcoins to avoid transaction fees, could be a huge success. And I'd donate to its creator :)
sgornick 16y ago
You mean something just like: http://www.YouTipIt.org http://www.YouTipIt.org ? (add a tip badge on your site and accept bitcoins) Here's a site with a YouTipIt badge: http://www.BitcoinMiner.com http://www.BitcoinMiner.com YouTipIt's fee is 0.01 BTC per tip, subtracted from the tip amount. ----- There's also a Hacker News / Reddit / Digg type of site, where you pay bitcoins to post, vote, and reply. But then you earn from anyone who subsequently votes or replies to your contributions. It's live now: http://www.witcoin.com http://www.witcoin.com
- khafra 16y ago
  Witcoin is fascinating; thanks for the link. But it seems like it could make trolls very rich.

donpdonp 16y ago

The author explains in the bitcoin forum that the library is his 20% project. from http://www.bitcoin.org/smf/index.php?topic=4236.0 http://www.bitcoin.org/smf/index.php?topic=4236.0 "Google staff have the ability to spend ~20% of their time on projects that interest them ... standard process for open sourcing our code ... checked by our lawyers for things like trademark/export compliance... This is why the code has our copyright at the top. This is not "official" in that it does not reflect some vast corporate master plan, we are not about to start accepting BitCoins for AdWords, we have not just dropped 200GHash/sec into the network and we are not going to fork the block chain (to mention just a few of the theories I've seen floating around)."

sgornick 16y ago

A good discussion about Bitcoin from about a month ago: http://news.ycombinator.com/item?id=2200705 http://news.ycombinator.com/item?id=2200705

mkramlich 16y ago

The Google connection is interesting. Because Bitcoin's greatest weakness is that the integrity of the system can be subverted by a malevolent participant who has enough computing nodes to make up the majority of computing power. Not that I'm saying Google would do this. Or that Google couldn't do this if they just used the main C++ implementation. It was just an interesting coincidence because when one thinks of entities that might have massive computing power at their disposal, things like various major national governments (the US NSA, China, etc.), or companies like Google and Amazon, come to mind.