Latest posts of: locksley

I'd say lots of people are interested in building 'wallet' functionality into their apps. Think of all the tip bots.

I wouldn't trust them with my coins as a wallet, but I'd trust them enough to transact small amounts on there.

I wrote a tutorial on how to build a javascript client side Bitcoin wallet, much like blockchain.info's "MyWallet".

It's something I certainly could've used when I first got started

Check it out and let me know what you think.

https://helloblock.io/docs/tutorials/how-to-build-a-wallet-1

My assumption is that ASIC miners optimize for the "hashes per joule" metric, as did GPU miners over CPU miners.

It would seem that after some time, the decision to mine Bitcoins would be based on if you could source energy cheaply enough.

When do we reach that point?

I'm not a hardware guy so I'm curious to understand what the upperbound limits are of ASIC mining from a technical perspective. How much more can we optimize?

Thanks!

Quote from: gmaxwell on May 03, 2014, 10:33:11 PM

How do pools secure their bitcoins? Well mostly pools are holding other people's bitcoins. Why bother securing them? (The answer: pretty poorly.)

Why bother securing them? Just concerned about attackers getting into the pool's bitcoind (if that's how they manage the keys), or if an attacker manages to ride your user session.

Do you think this isn't something I should worry about? I saw that some pools were hacked last night and the compensation came out of the pool owner's pocket :s

Quote from: beatljuice on May 03, 2014, 09:16:11 PM

Maybe I'm a dummy, but I consider Coinbase safe enough for up to 10 BTC (or $4000-$5000). My bitcoin stays invested, so I've never had that much in there.

What do you mean by 'invested'?

New to mining, I'm curious to see how everyone secures/stores their funds?

The safest way I can think of is cold generation of private keys and using the public address to withdraw from pool sites, or if you're solo mining, specifying that public address in the coinbase transaction.

Is this how people do it? Seems a bit inconvenient though when you want to spend your coins. Where do you keep it afterwards?

https://helloblock.io

We’ve built a Blockchain API so developers can focus on the important stuff (app logic, UX) rather worry about bitcoind.

This was built out of frustration of both bitcoind and the blockchain.info API. We previously built www.tippercoin.com (send BTCs via a tweet) and www.sparecoins.io (Chrome extension wallet) via these tools. However, bitcoind just doesn’t give the data you need and blockchain.info isn’t developer friendly, e.g. no testnet, goes down quite often, weird http codes

We’ve also built a programmatic faucet API so you can write proper integration tests! (https://helloblock.io/docs/ref#faucet). This comes with a block explorer as well for both testnet/mainnet (https://helloblock.io/latest, https://test.helloblock.io/latest)

Let me know what you guys think.

So there's no way to check through bitcoind? Would I be looking at a node reimplementation then?

Running bitcoind -testnet locally (about 8 connections) at the moment and testing 'sendrawtransaction'.

However, I'm wondering if there's a way to check how many nodes have picked up the transaction?

I've also noticed it takes a while before it gets in the unconfirmed pool on testnet.btclook.com

How does blockchain.info do it with /inv ?

https://blockchain.info/inv/d7524b67ddb9337a1c25fb79224ad124115c032d9075f839ead765c1884796c7

Thanks guys

Answering my own question, but I eventually found this https://bitcoinfoundation.org/blog/?p=290

Summary: In 0.9, OP_RETURN data TxOut will become a standard transaction type. However, this is controversial, and some miners may just reject OP_RETURNs with data junk.

I have an idea that uses OP_RETURN. However, the wiki states that "Note that this mechanism is not yet a standard transaction type, and thus will not be relayed by nodes on mainnet."

If it doesn't get relayed by nodes (and rather only included if you've mined that block), then how did this particular transaction get in there?

https://blockchain.info/tx/eb31ca1a4cbd97c2770983164d7560d2d03276ae1aee26f12d7c2c6424252f29

Also, I was wondering what is meant by this in the IsStandard() method?

Code:

    // only one OP_RETURN txout is permitted
    if (nDataOut > 1) {
        reason = "mucho-data";
        return false;
    }

See here https://github.com/bitcoin/bitcoin/blob/master/src/main.cpp#L408-412

You are correct, there is no "tx time" embedded in the blockchain for individual transactions, only for blocks themselves.

There exists only a pseudo "tx time", which is based on when the node received the transaction.

For example, this is what blockchain.info means by "received time". https://blockchain.info/tx/dc55d9c6ec03ceccf0db43d29e7d626a8b107f41066e3917f30398bb01dda2b5

However, as you can imagine, this can vary greatly between nodes.

Has anyone had experience in using MtGox v2 API vs v1?

I can't seem to find any benefits v2 provides, apart from better namespacing. Checked here https://en.bitcoin.it/wiki/MtGox/API/HTTP/v2

I ask because I'd like to use the mtgox ruby gem which is still in v1.

Thanks

Seems to be lots of hype but no product.

1. Circle Raises lots of money.
2. XYZ Wall St exec joins board.
3. Circle spends shitloads buying .com domain

etc ...

From what I can see, they're trying to do everything Coinbase has already done.

But then again, I'm just a blind outsider listening to the inner workings of a factory.

What are people's thoughts?

Quote from: kireinaha on December 18, 2013, 09:44:29 PM

...a new currency is developed, and you're pissed because people want to discuss the exchange value?

Yes, because it's mostly fluff and has the unfortunate effect of stealing the media spotlight from products which do add value for Bitcoin. For example, things like BitRated and ProofOfExistence are potential game changers that didn't get nearly enough attention.

Anyway, I edited the title/body to sound less dicky.

Quote

what are you talking about? price drives a ton of the things you want to happen here, so it should be a part of the conversation. price goes up, ALL of the things you mention get more attention put on them, and more work put into them.

That's a valid point.

I think Aaron Levie put it best - "The challenge with Bitcoin is the bubble came before the utility was proven, not the other way around." (https://twitter.com/levie/status/406932229256773632)

There have been 3 bubbles now and each time it's the same thing at varying levels of intensity. People always generate technical charts detailing price movements, talking about this/that price point as if it meant something. "What will Bitcoin reach in 2014?". Hindsight analysis is always applied with X event explaining Y movement. Cyprus this. China that.

I'm getting sick of it. It adds no value. I, for one, am glad that the price tanked, if it'll mean people will talk less about it.

Hopefully the hype is gone so when can start building the actual Bitcoin economy, the real guts of it - merchant adoption, international remittance, developer infrastructure, allowing transaction types that were previously impossible (e.g. MULTISIG, ANYONECANPAY etc ...).

Thanks for reading.

/rant

[EDIT:] Toned down the language.

Thanks! We love Coinbase and hold some BTC there. But, their API doesn't offer the flexibility we need.

Hey guys,

We just built a Chrome Extension Bitcoin Wallet (open sourced of course). The point was to make sending small amounts of Bitcoin much easier, because you always see random addresses scattered here and there. Opening up your Desktop client takes ages and even using a hosted wallet is too many steps if you just want to send 0.001 BTC for example.

This encrypts/stores your private keys in Chrome Storage, the decrypt key is a SHA256 digest of your password. We use Blockchain.info to propagate transactions and get transaction history on your addresses.

http://www.sparecoins.io

Would you love know what you guys think and will happily take feature requests.

I got tired of seeing raw Bitcoin addresses, they can be hard to differentiate, whether you're a consumer or a developer.

Here's a little project we made that converts public addresses into unique identicons by hashing the public addresses.

e.g. 1F1tAaz5x1HUXrCNLbtMDqcw6o5GNn4xqX converts to

It has a simple api endpoint, or you can fork the repo and host it yourself. Enjoy!

http://identico.in/