
Datacoin - karlzt
http://datacoin.info/index.php?id=index
======
nwh
Somehow I don't think many people will be willing to store arbitrary data like
this on their hard drives. It only takes one person to inject something
illegal before the entire blockchain becomes incredibly dangerous to handle.
There's not really much worthwhile in storing something in this expensive
format over an http/ftp/gopher server server if it's not illegal in some way,
which will probably lead to it being quickly unsavoury.

On the technology side, you'll get to the point where no solved blocks include
any data because it's causing massive orphans for the miner. I can't see this
ever working the way the author intends. That already happens in the bitcoin
system where blocks are extremely well compacted, and still people don't want
to include transactions against the risk of losing their income.

~~~
jontas
This is also an issue with Freenet. Granted, Freenet has not taken off the way
Tor has, however, it is still chugging along.

~~~
blantonl
Won't this process become much more expensive over time, thus invalidating the
attack vector?

------
zaroth
A blockchain isn't a particularly great data storage or retrieval mechanism.
The core value of the blockchain with proof-of-work is achieving global
consensus through majority hash voting. I don't see why data storage would
benefit from this kind of structure.

For example, the basic premise of the blockchain is a backwards linked list.
New transactions in the chain are collected into blocks which must be placed
at the tail of the blockchain. Miners race to get their blocks on the tail.
This is a great property if you're trying to prevent counterfeiting and
provide protection against double-spends, but what does counterfeiting and
double-spending have to do with data storage?

Blockchains are incredibly cool, but when you have a hammer...

~~~
pault
What would be a better platform for storing, say, a database of torrent magnet
links, or a dump of leaked documents, in a way that makes censorship
computationally infeasible?

~~~
zaroth
How can you make censorship computationally infeasible? Implicating everyone
running a client as co-conspirators for distributing top secret documents
seems like a bad plan. FBI agents busting down doors of anyone running these
clients would make a lot of people think twice about running one.

Compare this to, for example, just running your own Tor hidden service with
the documents you want to share. Doesn't implicate anyone, and actually
respects the privacy of anyone interested in reading what you are serving.
Well, maybe :-)

~~~
madgenius
botnets. The ad revenue of the information hosted by datacoin could be linked
to demand for advertising. Then, if datacoin mining is outlawed, it will
become more profitable the way drug dealing is more profitable because it is
illegal. People wanting to make money will mine using VPN or by using botnets.
Some CPUs will stop mining if it is outlawed, only making it more profitable
for those who continue.

------
jaekwon
What is the economics of the incentive system for data storage vs cost of
storage?

For the miner who mines a block, he only needs to store the additional data in
the block. But the commons of the miner network needs to store all data, so
isn't there a tragedy of the commons? Perhaps the number of miners would
continue to wind down until only a handful can actually service the network,
reducing the security and usefulness of the system.

What incentivizes a miner to actually store the data anyways? Are there proper
incentives to ensure that miners or whatnot actually continue to store all
that data?

The right incentive system would allow users to pay for data downloaded. Not
sure if that's in the spec or code.

------
themgt
I really want to like these storage-coin ideas, but it seems like the obvious
advance needed is a conceptual way to distribute the blockchain so each
individual computer doesn't have to hold all of the data, and (hand-in-hand)
to eventually allow data to be removed from the chain. I don't understand how
they can otherwise be sustainable long-term. It also seems like they could
take some lessons from BitTorrent, where peers get credit for transferring
data rather than computations.

~~~
stormbrew
I'd be much more interested in a blockchain designed to secure other sources
of data than one that attempts to store data itself (NMC or DTC). Hashes and
signatures of important files, personal and corporate public keys, etc.

~~~
jzwinck
You can put file hashes in Datacoin, no? If we made a coin that only allowed
storing hashes, folks could just encoded their data to make it look like
hashes.

Unless...we could build a system that would allow storing of hashes but only
after somehow verifying that the submitter actually possessed data of a
nontrivial size which produced that hash value. So maybe a little less like
regular hashing and a little more like public-key encryption? Just a thought.

~~~
stormbrew
Well, obviously you could never entirely prevent abuse (as bitcoin shows),
only make it costly. Low fixed limits on storage size would at least keep
people from throwing an avi in most of the time.

I think maybe hashes wouldn't make much sense, though, anyways. If you were
say ubuntu and you wanted to make your releases verifiable through the
blockchain you'd just put a public key in under ubuntu.releases and it'd be
the signature of the file matching that would matter.

When it comes right down to it I guess I basically want a namespaced,
blockchain-verified, pgp. With maybe more flexibility about key types so you
could throw things like ssh keys or bitcoin addresses or such in. Or maybe
dnscurve/dnssec keys.

And yeah, you could use either namecoin or datacoin to do this, but I think
they're trying to be too much and that will be a problem. Could you imagine
how big a block chain that contained the entirety of dns as it exists now
would be? There's a reason the internet moved from distributing a hosts file
to everyone.

------
VladRussian2
>Data is stored in the blockchain forever and can be retrieved using a
transaction hash as an identifier.

so, if someone stores any piece of copyright material the MPAA/RIAA would need
to destroy whole ecosystem of the given coin? bamboo roots come to mind.

------
jared314
If you combine this with something similar to Namecoin, for dns, this might be
an interesting distributed website hosting solution. Or, perhaps publishing
scientific studies (documents and data) instead of using academic journals[1].

It might be horribly inefficient as a hosting solution, but i'm sure that can
be optimized.

[1]
[https://news.ycombinator.com/item?id=6960989](https://news.ycombinator.com/item?id=6960989)

------
maaku
There's absolutely no reason to construct a new chain for this. You can do
data storage in the block chain using Merkle trees whose roots are committed
in the coinbase string or an OP_RETURN txout.

------
t0
What makes it valuable as a currency? Are people expected to buy DTC to pay
storage fees? I don't know that this will work from an economics standpoint.

~~~
LoganCale
Not all Bitcoin-derived technologies are necessarily intended to be an actual
currency, though some do still get traded for other currencies (usually for a
very low amount).

~~~
maaku
Those which don't need a new currency shouldn't create one. Build on top of
bitcoin instead.

~~~
makomk
The Bitcoin developers really don't want people storing data in the Bitcoin
blockchain.

~~~
maaku
Because you don't need to. (I am a bitcoin developer, btw.) You can do just
fine committing summaries of data (e.g. a Merkle hash root) to the coinbase
string in cooperation with a miner, or to a short data field in a provably
unspendable output of any transaction. Both of these work fine on vanilla
bitcoin, accomplish the typical goals of blockchain data witness, don't
require full nodes to store your data, and don't require a new coin.

~~~
madgenius
wrong. data witness?? what is good about that? Someone may want to submit
content and generate an income off of the ad revenue from that content. Why
should Google collect ad revenue for videos on youtube created by individuals?
The person making the movie should get the ad revenue.

Bitcoin can do this?!! HAHA don't make me laugh. Proof of storage was not done
academically until after the release of Bitcoin, which is probably why Bitcoin
is not designed with mass data storage in mind.

Datacoin is not a currency, it is a crypto anarchist corporation. It is the
first publicly traded company not traded on any centralized stock exchange.

------
MarcusVorenus
What's the difference with Namecoin other than the hashing algorithm and block
speed?

~~~
lukifer
More storage space (although still fairly small).

------
mikemoka
bitcoin can already provide proof of existence in a similar way if that is the
key advantage expressed, if they claim to be able to store an indefinite
amount of future data instead, as could be inferred by a quick scanning of the
text, I find it very hardly scalable at all, there could be useful files of
any size passing through the voting system and the blockchain should be
replicated by each client on the network in theory in order to safeguard the
network from possible missing nodes

------
tibbon
Maybe I just suck at this, but I've found that compiling the needed tools for
various cryptocurrencies is kinda hellishly difficult. I've been trying to get
this one going on OS X Mavericks for the past hour with little luck.

I'd really like to play with more of these, but the state of the documentation
across the board for them (except Bitcoin) seems to be slim at best, non-
existant and incorrect at worst.

Trying to figure it out and post my results to the Github issue tracker...

~~~
pault
They all have basically the same dependencies and build process. Incidentally,
I'm in the middle of setting up a docker image for just this purpose, so I can
download any satoshi reference client fork and compile it with a build script
without worrying about a malicious client stealing my wallets. If all goes as
planned I should be able to just pass it the git repo address and use json-rpc
to play around with it. <3 docker.

EDIT: I think people don't consider the security implications of downloading
$altcoin_of_the_day_client and running it on the same machine they keep their
bitcoin wallet on. It's like leaving all of your cash on your kitchen table
and letting strangers walk in and out of your house all day. I'd say there's a
pretty good chance that anyone downloading an altcoin client already has a
bitcoin wallet sitting in their home directory, and it would be trivial for
someone to release a malicious client and steal coins from unsuspecting users.

~~~
tibbon
Damn. Good point. I was actually thinking of firing up an EC2 instance just to
test/play with them (clearly, mining with AWS isn't generally profitable, but
its ok to play with for a few hours).

Lemme know if you get the docker stuff up and running. I've been meaning to
try that, but haven't yet.

------
BenjaminN
How many of those do we need? At least this one is using flat design. Guys,
you should call it flatcoin, that's a good name too.

~~~
romanovcode
About as many as NoSql databases.

------
sudheendrach
Huh.. Yet another Alt Coin wants Donations in BTC??
[http://prntscr.com/2e111d](http://prntscr.com/2e111d)

------
dataangel
Anyone know if this is merge mined with Primecoin or does it just use the same
algorithm?

~~~
whyenot
not merge mined

------
habosa
Why is CPU mining a plus?

~~~
hendzen
The goal of CPU mining is to making it difficult for well-funded parties to
control the network's hashpower by amassing powerful GPU/FPGA/ASIC miners. If
you look at the distribution of hashpower [0] in the Bitcoin network, you can
see that two pools (GHash.io and BTC Guild) together control a majority of the
network. To be fair, many believe that this is nonetheless incentive-safe
because the gains from executing double-spends would be small compared to the
lost mining revenue from the subsequent massive drop in value of BTC.

That said, there was a double spend executed by a rogue operator of GHash.io
[1].

[0] - [https://blockchain.info/pools](https://blockchain.info/pools)

[1] -
[https://bitcointalk.org/index.php?topic=321630.msg3445371#ms...](https://bitcointalk.org/index.php?topic=321630.msg3445371#msg3445371)

------
mbloom1915
very interesting, not sure even bitcoin will stay afloat but there is room for
other players to make a splash

------
ronaldsvilcins
Well, this is very interesting idea...

------
pearjuice
And another pump&dump coin sees the bright daylight.

