HN Explorer

12 comments

[ 2.6 ms ] story [ 38.7 ms ] thread
spiderbro
Here are some links to get started:

Block explorer: http://blockscan.com/

Official site (under construction) https://counterparty.co/

Installation instructions: http://counterpartyd-build.readthedocs.org/en/latest/

Github: https://github.com/PhantomPhreak/counterpartyd

Discussion thread: https://bitcointalk.org/index.php?topic=395761.0

pyalot2
So thing is this, you're using proof of burn and/or some derivative of proof of stake or whatever.

Thing is what proof of * you use don't matter. You're not in control of the chain, and anybody can just spam the bitcoin blockchain with fraudulent transactions (double spends, etc.)

And the only way for anybody want to accept any of those assets, would be to calculate the probability of having a real asset in hand from the entire blockchain history that this amount derives off of.

So, very sorry to say that, but, this'll crash&burn. That's just how it is if you forgoe the iron guarantees of proof of work.

spiderbro
Could you give an example of a double spend attack on XCP?

From what I understand, XCP transactions guarantee atomicity and funds are swept from addresses to fund any bets/orders immediately. The risk of double-spending XCP is the same as the risk of double-spending BTC as XCP relies on bitcoin's proof of work.

Please correct me if I'm wrong.

pyalot2
XCP would rely on the blockchain, and therefore it's atomic transactions are executed. However, the ones putting the transactions in the chain, are not XCP miners. They're bitcoin miners, they don't care what extra information you attach. And by extension, they don't care if they violate some rule in your protocol.

This basically means that XCP-looking transactions will appear in the blockchain, however, they will be invalid, because by the rules of XCP their outputs would already be spent.

In Bitcoin this is an invalid transaction, and it never enters the public ledger. This important because, it allows you to shortcut the path to figure out if an address has unspent outputs. Figuring out quickly if an address has unspent outputs or not is important for miners (they need to produce valid blocks), and it's important for participants to transactions, because it means the recepient can quickly verify that the sender is intending to make the transaction, and that a transaction, sufficiently confirmed, is not double spent. The recepient relies on the work of everybody who produced a block. And in turn, everybody who produces a block relies on the work of everybody before AND on the work of everybody after (who bases their block on his).

This is what I mean by iron-clad guarantee against a double spend.

But if nobody can reject an invalid TX for XCP, that means verifying that something has unspent outputs is an extremely expensive task. And the longer transactions go on, the more expensive this task becomes. And nobody can put in some kind of "block" that could be rejected by others to "proove" that some balances on addresses are now valid up to that point.

This means that in a short time, XCP will become unusable for everybody as the XCP-TX spam rises and everybody is checking the entire bitcoin blockchain over and over and over for XCP-looking TXes to figure out if the coin he thinks he got, aren't actually double spends.

spiderbro
Ok I think I understand your point that XCP-invalid-TX spam cannot be filtered at the point of origin like invalid BTC transactions and a motivated attacker could spam the network to make it extremely slow to use XCP.

I think this is a valid concern, even if somewhat mitigated by the 0.0001 BTC transaction fee. I'll post this to the BTCTalk thread and see if someone smarter than me has an idea to defend against it.

qwertyboy
They are actually not using proof of burn. Counterparty is a decentralized exchange that sits on top of bitcoin. As such, I don't think it should be minable, not with proof of work and not with proof of anything.

Proof of burn was used during an initialization phase (let's call it distributed minting) which is over. Should really check it out more thoroughly, it looks like a pretty neat idea.

neals
You might need to read this though (I sure did, still don't really get it)

https://counterparty.co/about/

cazzoduro
2 virtual objects + secure peer to peer exchange of those objects.

what is so hard about getting that...

dmix
Can someone "explain like I'm 5" what some of the use cases are for this service? I've been following bitcoin and distributed services for a while and I'm still confused (or lazy).

The website copy is extremely abstract and non-specific. It's in need of a copywriter.

PhantomPhreak
Counterparty is software that allows you to create and trade virtual assets (including BTC), make bets, pay dividends, and more, with all other Counterparty users, safely and pseudononymously, with no middleman at all. It extends Bitcoin's functionality beyond simply moving money from one address to another to that of a larger collection of standard financial tools.
spiderbro
Here are a couple of uses cases off the top of my head. This is by no means comprehensive.

* The ability to issue shares in your company/startup and have them be traded from Day 1. Unlike BTCT/BitFunder/Havelock, Counterparty is a P2P protocol and cannot be shut down by regulatory agencies. Kind of like BitTorrent.

* The ability to trade XCP for Bitcoin and vice versa without relying on any fallible counterparty. There is no centralized exchange to steal money from you or fail like MtGox. There is no escrow required to trade with peers because Counterparty guarantees atomicity of transactions.

* The ability to place a variety of different bets. Currently the protocol has support for simple contracts-for-difference (CFDs) and binary Equal/NotEqual bets. Why is this useful? You could for example hedge your exchange rate risk completely by being short a XCP/USD contract. This allows you to hold your wealth in cryptocurrency but have no exchange rate risk. Another use case is sports betting. There was a friendly bet on the Super Bowl, for example.

cazzoduro
It let's you trade tokens using bitcoin... i hope you understand that...