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Selasa, 29 April 2014

Bitcoin 2.0: Unleash The Sidechains

“Cryptocurrencies will create a fifth protocol layer powering the next generation of the Internet,” says Naval Ravikant. “Our 2014 fund will be built during the blockchain cycle,” concurs Fred Wilson. And Andreessen Horowitz have very visibly doubled down on Bitcoin.

Even if you don’t believe in Bitcoin as a currency, and I’ll grant there’s plenty to be skeptical about, you should be thinking: huh, a lot of extremely smart and successful people think that its underlying technology is a pretty big deal. But as I wrote myself just a few weeks ago, there’s a big difference between blockchain technology and Bitcoin itself, right?

…Maybe not.

A brief technical refresher: “blockchains” are the distributed-consensus technology introduced to the world by the mysterious Satoshi Nakamoto, wherein a peer-to-peer network is used to codify and cryptographically verify transactions, without any central authority. What’s more, transactions can be orchestrated by programmable contracts.

Bitcoin is both the first and most successful blockchain application, but there are many, many other “cryptocurrencies,” known as “altcoins.” What’s more, there are numerous other, non-currency applications being built on new blockchains, notably Namecoin and Ethereum, and several proposals for expanding and evolving Bitcoin itself, eg ZeroCoin, MasterCoin, Colored Coins, etc.

I realize this all sounds like abstruse hair-splitting to those not yet mentally invested in cryptocurrencies; but as Ravikant put it at TC Disrupt seven months ago:

…so, continuing that metaphor, imagine for a moment that it’s 1995 and you’re just beginning to notice that, over the last year or two, those weird crusty techies who sit in the corner have all started talking excitedly about “HTTP” and “HTML” and “cookies” … which apparently power this thing called the “web.”

So. We’ve got Bitcoin and its blockchain; and we’ve got scores if not hundreds of other blockchains, powering various altcoins and Namecoin and (soon) Ethereum et al. But blockchains, like social networks, benefit from a network effect. The most popular becomes the most resilient, the most powerful, the most valuable; and Bitcoin’s blockchain is, by far, the big dog today. These two facts have provoked a certain amount of anti-altcoin vitriol.

On the other hand, other blockchains are where most of the interesting innovation is happening. Namecoin as a DNS replacement; Ethereum as a generic platform for any kind of blockchain technology; hopefully some kind of blockchain replacement for X.509 certificates; SolarCoin for solar power; Dogecoin for those of us who love absurdism for its own sake; etc etc etc. The Bitcoin blockchain, despite/because of the megawatts of power poured into it, has grown sluggish and slow to change, a victim of its own success, which impedes the pace of innovation…

…or so I thought, until I met with Austin Hill and Adam Back. Hill is the former founder and CEO of Zero-Knowledge Systems, a multi-million-dollar startup that was a good 15-20 years ahead of its time; Back is the inventor of the Hashcash algorithm which powers Bitcoin. They have considerable credibility, in other words — and they’re building a stealth “Blockchain 2.0″ startup, based in part on the notion of “sidechains.”

Sidechains are new blockchains which are backed by Bitcoins, via Bitcoin contracts, just as dollars and pounds used to be backed by cold hard gold. You could in principle have thousands of sidechains “pegged” to Bitcoin, all with different characteristics and purposes … and all of them taking advantage of the scarcity and resilience guaranteed by the main Bitcoin blockchain, which in turn could iterate to implement experimental sidechain features once they have been tried and tested.

If sidechains take off, though — which will require some changes to the core Bitcoin protocol — this probably bodes ill for the existing altcoins. Not surprisingly, the proposal has attracted a fair amount of skepticism, not least from Vitalik Buterin, the chief scientist of Ethereum, who argues that sidechains require not just protocol changes but “the permission and active assistance of 50% of all Bitcoin mining pool operators.”

Why should you care? Two main reasons. One: because if Ravikant, Wilson, Andreessen, Hill, Back, etc. are correct, then in the long run, blockchain-backed cryptocurrencies could become the substrate of entire economies. Hill says: “I want to build a blockchain that could support a nation-state putting its national currency and phasing out paper dollars.”

Or, as A16Z’s Balaji Srinivasan describes a different-but-similarly-ambitious notion:

Two: because, as Hill said to me,

Never mind “don’t be evil”; we want to build a company that actually can’t be evil.

…by which he means, an organization which is limited by contractual obligations built into and enforced by its blockchain(s).

The distributed nature of Bitcoin has caused people to speculate about autonomous corporations powered by blockchains, which sounds like a creepy Kafka-meets-Gibson notion if I ever heard one. On the other hand, a company which committed to behaving in a particular way, not with a mere promise, but with an enforceable and cryptographically ironclad contract, might be much worthier of the public’s trust than your standard amoral corporation.

This is, of course, all highly speculative verging on cloud-cuckoo-land until people actually start shipping code which turns these notions into reality. What interests me most about sidechains is that, if implemented, they might bring that day closer, by aiding and accelerating the entire ecosystem of blockchain innovation. And I’m awfully curious about what Hill and Back still have up their sleeve (no, they didn’t tell me.) Interesting times indeed.

Image credit: Wikimedia.

Senin, 28 April 2014

Bitcoin 2.0: Unleash The Sidechains

“Cryptocurrencies will create a fifth protocol layer powering the next generation of the Internet,” says Naval Ravikant. “Our 2014 fund will be built during the blockchain cycle,” concurs Fred Wilson. And Andreessen Horowitz have very visibly doubled down on Bitcoin.

Even if you don’t believe in Bitcoin as a currency, and I’ll grant there’s plenty to be skeptical about, you should be thinking: huh, a lot of extremely smart and successful people think that its underlying technology is a pretty big deal. But as I wrote myself just a few weeks ago, there’s a big difference between blockchain technology and Bitcoin itself, right?

…Maybe not.

A brief technical refresher: “blockchains” are the distributed-consensus technology introduced to the world by the mysterious Satoshi Nakamoto, wherein a peer-to-peer network is used to codify and cryptographically verify transactions, without any central authority. What’s more, transactions can be orchestrated by programmable contracts.

Bitcoin is both the first and most successful blockchain application, but there are many, many other “cryptocurrencies,” known as “altcoins.” What’s more, there are numerous other, non-currency applications being built on new blockchains, notably Namecoin and Ethereum, and several proposals for expanding and evolving Bitcoin itself, eg ZeroCoin, MasterCoin, Colored Coins, etc.

I realize this all sounds like abstruse hair-splitting to those not yet mentally invested in cryptocurrencies; but as Ravikant put it at TC Disrupt seven months ago:

…so, continuing that metaphor, imagine for a moment that it’s 1995 and you’re just beginning to notice that, over the last year or two, those weird crusty techies who sit in the corner have all started talking excitedly about “HTTP” and “HTML” and “cookies” … which apparently power this thing called the “web.”

So. We’ve got Bitcoin and its blockchain; and we’ve got scores if not hundreds of other blockchains, powering various altcoins and Namecoin and (soon) Ethereum et al. But blockchains, like social networks, benefit from a network effect. The most popular becomes the most resilient, the most powerful, the most valuable; and Bitcoin’s blockchain is, by far, the big dog today. These two facts have provoked a certain amount of anti-altcoin vitriol.

On the other hand, other blockchains are where most of the interesting innovation is happening. Namecoin as a DNS replacement; Ethereum as a generic platform for any kind of blockchain technology; hopefully some kind of blockchain replacement for X.509 certificates; SolarCoin for solar power; Dogecoin for those of us who love absurdism for its own sake; etc etc etc. The Bitcoin blockchain, despite/because of the megawatts of power poured into it, has grown sluggish and slow to change, a victim of its own success, which impedes the pace of innovation…

…or so I thought, until I met with Austin Hill and Adam Back. Hill is the former founder and CEO of Zero-Knowledge Systems, a multi-million-dollar startup that was a good 15-20 years ahead of its time; Back is the inventor of the Hashcash algorithm which powers Bitcoin. They have considerable credibility, in other words — and they’re building a stealth “Blockchain 2.0″ startup, based in part on the notion of “sidechains.”

Sidechains are new blockchains which are backed by Bitcoins, via Bitcoin contracts, just as dollars and pounds used to be backed by cold hard gold. You could in principle have thousands of sidechains “pegged” to Bitcoin, all with different characteristics and purposes … and all of them taking advantage of the scarcity and resilience guaranteed by the main Bitcoin blockchain, which in turn could iterate to implement experimental sidechain features once they have been tried and tested.

If sidechains take off, though — which will require some changes to the core Bitcoin protocol — this probably bodes ill for the existing altcoins. Not surprisingly, the proposal has attracted a fair amount of skepticism, not least from Vitalik Buterin, the chief scientist of Ethereum, who argues that sidechains require not just protocol changes but “the permission and active assistance of 50% of all Bitcoin mining pool operators.”

Why should you care? Two main reasons. One: because if Ravikant, Wilson, Andreessen, Hill, Back, etc. are correct, then in the long run, blockchain-backed cryptocurrencies could become the substrate of entire economies. Hill says: “I want to build a blockchain that could support a nation-state putting its national currency and phasing out paper dollars.”

Or, as A16Z’s Balaji Srinivasan describes a different-but-similarly-ambitious notion:

Two: because, as Hill said to me,

Never mind “don’t be evil”; we want to build a company that actually can’t be evil.

…by which he means, an organization which is limited by contractual obligations built into and enforced by its blockchain(s).

The distributed nature of Bitcoin has caused people to speculate about autonomous corporations powered by blockchains, which sounds like a creepy Kafka-meets-Gibson notion if I ever heard one. On the other hand, a company which committed to behaving in a particular way, not with a mere promise, but with an enforceable and cryptographically ironclad contract, might be much worthier of the public’s trust than your standard amoral corporation.

This is, of course, all highly speculative verging on cloud-cuckoo-land until people actually start shipping code which turns these notions into reality. What interests me most about sidechains is that, if implemented, they might bring that day closer, by aiding and accelerating the entire ecosystem of blockchain innovation. And I’m awfully curious about what Hill and Back still have up their sleeve (no, they didn’t tell me.) Interesting times indeed.

Image credit: Wikimedia.

Sabtu, 19 April 2014

Bitcoin Falls Below The $400 Mark, Down More Than 60% From Its All-Time High

Bitcoin reached another milestone today, with the cryptocurrency falling below the $400 per-coin mark. Bitcoin sold for over $1,100 inside of the last 52 weeks.

The price correction was driven by news from China, as it often has been. Fresh rumors of a government crackdown on the currency in the country, which could blunt demand and adoption, and therefore impair its value, sent the price of bitcoin down a quick 10 percent. It has since continued to slip.

According to Bitcoin Average, the average price of bitcoin is currently around $388, down from a 52-week high of roughly $1,132. Coinbase has the current price of bitcoin at around $394, down from a peak of $1,126.

Bitcoin had a good start to 2014, rising from around $770 to north of $900. Here’s the Coinbase one-year chart:

Screen Shot 2014-04-10 at 1.53.48 PM

It’s worth noting that total bitcoin transaction volume has also weakened in the past few weeks. Here is Coinbase’s chart of bitcoin transactions per day. Keep an eye on the trend following the early March spike:

Screen Shot 2014-04-10 at 1.55.54 PM

Divining the next short-term move in bitcoin’s price is something of a fool’s gamble — and I am as guilty of this as anyone — meaning that recent declines could merely be a trough. But with falling volume and falling prices, bitcoin’s vital signs are not as strong as they once were.

As we’ve discussed ad nausem, bitcoin’s network is the key to its value. However, it could be that the network’s activity has not grown quickly enough to support declining speculative interest in bitcoin. That’s my best guess, at least.

So here’s the question: What next centennial mark will bitcoin reach? $300 or $500?

IMAGE BY FLICKR USER Hamed Al-Raisi UNDER CC BY 2.0 LICENSE (IMAGE HAS BEEN CROPPED) 

Rabu, 16 April 2014

10 Best Bitcoin Wallets For Secure Bitcoin Storage

We’ve talked about ways to get your hands on Bitcoin, as well as exchanges where you can buy and sell Bitcoin, so an overview of some of the more notable Bitcoin wallets out there is probably long overdue. Generally, Bitcoin wallets, despite the name, don’t actually store Bitcoins. Instead, wallets consist of two keys, a public key and a private key, that are used to associate particular Bitcoins with your wallet. The public key allows you to receive Bitcoins, while the private key allows you to spend Bitcoins.

Blockchain

As you might imagine, the security of your private key is incredibly important, lest someone gains access to your wallet and spend all the Bitcoins you’ve mined or traded for. Which wallet you choose depends on whether utmost security or increased convenience is more important, and it’s recommended that you don’t stick to one particular type of wallet. Here’s a list of 10 different wallets for secure Bitcoin storage.

1. Bitcoin Core

Bitcoin Core is the original Bitcoin wallet, originally developed by Satoshi Nakamoto and continually updated by the core Bitcoin development team. While it doesn’t have the advanced features of Armory or the social aspect of Hive, Bitcoin Core is probably the most scrutinized and worked-on wallet out there, making it a trustworthy choice.

Bitcoin Core

One thing to be aware of is the fact that Bitcoin Core is a fully fledged node of the Bitcoin network. So it requires the entire blockchain to run. Bitcoin Core is available on Windows, Linux and Mac, and is also available as a Ubuntu PPA.

2. Multibit

Multibit is a lightweight software wallet. As with most software wallets, Multibit encrypts your private keys locally (or on a USB stick). One useful characteristic of Multibit is that it doesn’t need to download the entire blockchain to access, send and receive funds. Multibit connects directly to the Bitcoin network and downloads only a small part of the blockchain, making it very fast to use.

Multibit

Since Multibit doesn’t download the entire blockchain, it also takes up a lot less space on your hard drive, which can be important in some situations. Multibit has also been translated into more than 35 languages and is available on Windows, Mac and Linux.

3. Electrum

Electrum is another lightweight Bitcoin wallet in the vein of Multibit. Electrum supports deterministic wallets or, in other words, generating multiple wallets from one seed. It also lets you sign and create transactions offline and export what it calls a "root public key", which lets compatible applications monitor your wallet. You can also import and export private keys from other Bitcoin wallets.

Electrum

Like Multibit, Electrum lets you perform Bitcoin transactions without having to download the entire blockchain, making transactions a lot faster. Electrum uses a network of servers to achieve this. Electrum is available for Windows, Mac, Linux and Android.

4. Hive

Hive is a Bitcoin wallet targeted at new users, with some interesting features. For one, Hive has an instant messaging style interface that lets you send and receive Bitcoins quickly and easily. It also has an integrated application platform and comes with some built-in apps that give you easy access to some of the more popular Bitcoin-related services available.

Hive

Hive even has an SPV backend to speed up starting time, as well as support for the Tor network for increased anonymity. You can also schedule wallet backups onto Dropbox and Time Machine. Hive is only available on Mac OS X, but is also coming to Android in the near future.

5. Armory

Armory is one of the most feature-rich and secure software Bitcoin wallets available today. Armory offers three different user modes: Standard, Advanced and Developer. Some of it’s security features include a graphical keyboard to protect against keyloggers, support for deterministic wallets, offline transactions and extensive cold storage options, including fragmented paper wallets.

Armory

Offline transactions significantly increase your wallet’s security and protects it from most security risks. It requires the official Bitcoin Core wallet, since Armory doesn’t have any networking features. Armory is available on Windows, Mac and Linux. It’s also available as a Ubuntu PPA.

6. Blockchain Wallet

Blockchain’s wallet has a few interesting security features designed to overcome some of the security risks inherent in online wallets. For example, Blockchain implements client-side AES encryption, protecting your wallet from a server side hack. It also has support for offline transactions, a double encryption feature and two factor authentification.

Blockchain Wallet

Blockchain not only lets you back your wallet up automatically onto Google Drive or Dropbox, but also lets you download your wallet manually. Blockchain also performs regular off-site server side backups every hour. There’s even a mobile wallet version of Blockchain for Android.

7. Coinbase

Coinbase is an online Bitcoin account, somewhat similar to PayPal. Coinbase also has a built-in Bitcoin exchange where you can buy and sell Bitcoin, and lets you send and receive money directly to and from email addresses. Coinbase is a centralized operation and stores all its Bitcoins on-site, but claims to store 85% of its Bitcoins in offline cold storage.

Coinbase

There are potential security and trust issues with Coinbase, especially since its operators have control over all Bitcoins, but the fact that it’s been heavily backed by prominent venture capital firms makes it less likely that Coinbase will run away with users’ Bitcoins. There is also a Coinbase Android app.

8. Coinkite

Coinkite is somewhat similar to Coinbase, in that it provides plenty of Bitcoin-related services such as Bitcoin debit cards and payment terminals alongside an online wallet feature. Coinkite uses BIP32 Heirarchical Deterministic (HD) wallets, which are stored in a custom Hardware Security Module (HSM) that is apparently isolated from the Internet. You can even request audit reports from Coinkite.

Coinkite

In the case of closure or failure, Coinkite has promised that it will publicize a symmetric key that contains all the extended private keys that have been distributed to Coinkite users. This will allow users to reclaim their funds from Coinkite, if the service shuts down.

9. BitAddress Paper Wallet

BitAddress is a web service that generates randomized public and private keys that you can use to receive, spend and store your Bitcoin. The big appeal of BitAddress is that it can create paper wallets. Paper wallets are a particularly secure form of cold storage, since the private key is only stored on a piece of paper and not on the Internet or in any form of software.

BitAddress Paper Wallet

Bear in mind that you’ll have to import your private key into some form of digital wallet, if you want to perform transactions. Thus, it’s probably best to use a paper wallet as a complementary form of Bitcoin storage alongside a software or online wallet.

10. Pi-Wallet

Pi-Wallet is currently the only commercially available hardware Bitcoin wallet. The Pi-Wallet is basically a Raspberry Pi running a software Bitcoin wallet, namely Armory. As such, it has all of Armory’s features in addition to a few perks that only a hardware wallet of this type can provide. For instance, the Pi-Wallet doesn’t have direct Internet access, adding another layer of protection.

Pi-Wallet

The Pi-Wallet is also portable, and as it’s built on a Raspberry Pi that makes it much less susceptible to viruses and trojans that can be used to steal Bitcoin from your average Windows computer. The site also has instructions on building your own Pi-Wallet.



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Selasa, 15 April 2014

What Bitcoin Users Need To Know About Heartbleed

If you’re using a bitcoin wallet or an online wallet or exchange, Heartbleed could be a very real problem for you and your BTC. Luckily, things have finally settled down after a few days of panic and there are a few very easy ways to ensure you’re protected.

First, understand that the core bitcoin protocol, which transfers bitcoin through the system, is unaffected. “Whilst the Bitcoin Core client will be updated to 0.9.1 to address the OpenSSL vulnerability, the core developers stress that the Bitcoin protocol itself is not affected by the Heartbleed bug,” wrote Venzen Khaosan on CryptocoinsNews.

That didn’t stop many exchanges from taking down some of their services just to be safe. Yesterday Bitstamp shut down “accregistration, login & all virtual currency withdrawal functions,” as it investigated the effect of Heartbleed on its servers. Anti-DDOS service Incapsula also had to update its servers to remain secure. Bitstamp has since restarted all functionality. The OpenSSL exploit essentially allows a dedicated hacker to methodically collect email addresses, keys, and log-ins from affected servers.

Other services, including Bitcurex and Blockchain.info are reported that they’ve patched and updated their services.

What about folks with wallets on their own machines? A bit of updating is in order. A new version of the Bitcoin Core, 0.9.1, just dropped, and it features improved security for wallets. Users should have openssl 1.0.1g or later. You can see your openssl version in the Help->Debug window in Bitcoin-Qt. Other wallets like Multibit have not updated (although they may not need to) but care should be taken to encrypt and password-protect your coins.

Screen Shot 2014-04-09 at 10.35.19 AM

In short, update everything that touches your bitcoin and don’t trust exchanges that haven’t explicitly explained their position on the exploit. Want more bad news? You should assume that all your usernames and passwords used over the past two years are compromised. This means you should change everything, not just your bitcoin data. A clever hacker could socially engineer her way into your wallet simply by knowing a few things about your online habits.

“I’m hoping the impact will be limited. Major sites will have to rotate their SSL keys after upgrading [...] Most sites should have the private keys for their wallets in a different server process where the data cannot be extracted this way. However it will not surprise me if a few sites are not working this way for whatever reason and might suffer thefts,” wrote Mike Hearn of the Bitcoin Foundation. All is not lost, but all is not great, either.

Senin, 14 April 2014

The 11GH/S HexFury Will Is The Latest In Low-Power ASIC Bitcoin Miners

If you’re a bitcoin nerd, you’ll know that finding cheap, low-power mining hardware is pretty hard to do. USB “thumb drive” miners are traditionally woefully underpowered – the little mining rig under my desk right now is running three three BlockErupters and I’m essentially paying for the pleasure of mining bitcoin – but this 11GH/s unit seems to have what it takes to at least make a dent in the blockchain.

Confused as to what this does? Read my tutorial for a bit of context. Essentially this board runs the calculations that makes bitcoin work and, more importantly, runs them fast enough to earn you a little money.

It’s sold by ASICRunner and is in stock right now. At a little over $265, it’s affordable to the average miner and it can run on a standard USB hub and host machine, which seems to include the Raspberry Pi. It uses last year’s Bitfury chips, special ASIC designed for mining, on a “stick” board with a single USB jack. This means you can place a bunch of these on a hub and because they aren’t as power-hungry as a traditional ASIC you don’t have to worry about them overheating.

Screen Shot 2014-04-04 at 4.13.07 PMWill you make much money with this rig? Probably not. It’s essentially baby’s first bitcoin miner and you’ll max out at about $15 a month until the difficulty goes up too far for this device to even be effective. However it’s an exciting change in the mining landscape and well worth considering if you want to attach a few of these together and try to make your money back that way.

via Cryptocoinsnews

Minggu, 13 April 2014

10 Best Sites To Help You Track Bitcoin Exchange Rates

Bitcoin may have become relatively more stable as of late, even after numerous security scares, but it’s still far from being completely stable. Bitcoin and other cryptocurrencies, unlike fiat currencies like the US Dollar, isn’t backed by governments and aren’t influenced by monetary policy. This makes it a lot more like gold than any other currency, since its value rests entirely on how much people are willing to pay, and how much its users believe in it. This, as you can imagine, can lead to volatility and uncertainty.

Winkdex

Given this uncertainty and potential for volatility, it would be quite a smart move to keep an eye on the value of Bitcoin, especially if you’re trying to make a profit from an investment. Even if you’re not an investor, it’s still a good idea to be aware, just in case. Here’s a list of 10 sites that you can use to track the value of Bitcoin.

1. Bitcoin Charts

Bitcoin Charts is probably the most comprehensive Bitcoin price tracker available. Bitcoin Charts tracks the price of Bitcoin in relation to a large number of currencies, including USD, EUR, GBP, JPY and even Ripple. Bitcoin Charts has a few different chart types and can even show moving averages and technical indicators such as accumulation/distribution and rate of change.

Bitcoin Charts

The time range for the charts can be as short as 1 day and as long as 8 years, with an All Data option. As you might expect, there isn’t enough data for the 4- and 8-year time ranges. Bitcoin Charts also has charts showing Bitcoin exchange volume distribution.

2. BitcoinWisdom

BitcoinWisdom tracks the price of Bitcoin on a number of major exchanges such as Bitstamp, BTC-e and Coinbase. BitcoinWisdom also tracks the price of Bitcoin in relation to other cryptocurrencies on exchanges such as Cryptsy and Bter. BitcoinWisdom has a few settings you can tweak, including chart styles and depth ranges.

BitcoinWisdom

The tracker updates in real time, and you can choose the time interval for the main graph, ranging from one minute to one week. Bitcoin Wisdom also has Bitcoin and Litecoin difficulty charts and mining calculators.

3. CoinDesk

CoinDesk’s Bitcoin price tracker has both their own Bitcoin Price Index (BPI), which averages the prices from three leading Bitcoin exchanges: Bitfinex, Bitstamp and BTC-e. The graph can display either the BPI, or price data from any of the three exchanges. Historical data for Mt. Gox is also included.

CoinDesk

CoinDesk can display both Closing and Open, High, Low, Close (OHLC) price data. The time frame for the graph ranges from 1 hour to an All setting that goes back as far as possible. You can also set a custom time frame.

4. Bitcoinity

Bitcoinity tracks the price of Bitcoin across a number of different exchanges and currencies. Unlike most trackers, Bitcoinity has a preferences section where you can customize your experience. You can, amongst others, choose the default theme, the precision of the price, whether to show prices in BTC or mBTC and hide trades smaller than a certain amount.

Bitcoinity

Bitcoinity has an alternate light-colored theme if you don’t like the default color scheme. The time range for the price chart ranges from 10 minutes up to a historical 2 year view. The change graph ranges from 1 minute to 1 hour. It also lets you zoom in and out.

5. Coinbase

Coinbase isn’t a dedicated price tracker, but still has a Charts view that tracks Bitcoin’s price. Coinbase has charts that track Bitcoin price in USD as well as the number of Bitcoin transactions per day. Coinbase is one of the few trackers that also tracks transaction volume, which may be of interest to some.

Coinbase

Like most other trackers, you can select the time range of the graph, from 1 day up to an All option. You can also set a custom time range. Coinbase doesn’t explicitly state the source of their price data.

6. Winkdex

Winkdex pools data from seven different exchanges, including Bitfinex, Bitstamp and CampBX, to provide an average price for Bitcoin. Winkdex weighs exchange prices according to transaction volume on the exchanges, so that high-price but low-transaction outliers will not greatly affect the average price.

Winkdex

Winkdex has a remarkably clean interface and gives you a number of range options, from as short as one day up to a Max option that shows all available data. Winkdex is still in beta and might have some bugs that need to be ironed out.

7. Blockchain

Blockchain draws its data from Bitcoinity, but presents it in a slightly easier to use way. Unlike Bitcoinity, Blockchain only tracks three currencies: USD, EUR and GBP. Blockchain also shows the BTC-e chat room in a small window, so you can keep up to date with all the gossip and discussion going on there.

Blockchain

The time range for the price chart on Blockchain ranges from 10 minutes up to 6 months, while the change graph ranges from 1 minute to 1 hour. You can also zoom in and out of the change graph.

8. Bitcoin Ticker

Bitcoin Ticker tracks the value of Bitcoin in real time on six different exchanges. These exchanges include BitStamp, BTCChina, Bitfinex and Kraken. Bitcoin Tracker also has a news ticker that shows all the latest Bitcoin-related news, as well as a real-time readout of buy and sell orders on the respective exchanges.

Bitcoin Ticker

The graph has a time range from 10 minutes to All Time. Bitcoin Ticker also has a Combined view mode that shows real-time price graphs for Bitfinex, Huobi, BitStamp and BTC-e on the same screen.

9. BigTerminal

BigTerminal tracks a large number of markets, including cryptocurrencies Bitcoin and Litecoin. As far as Bitcoin is concerned, BigTerminal can track both average and exchange-specific prices, namely on BitStamp, BTC-e and Coinbase. You can compare charts and even change the currency BigTerminal displays in.

BigTerminal

BigTerminal’s graph defaults to a quarterly view, but you can go as short as 15 minutes and as far back as a historical view. BigTerminal includes social sharing options as well as chart and drawing tools. You can even save the charts in a few different formats.

10. Bitwat.ch

Bitwat.ch does things a bit differently. Instead of tracking the value of Bitcoin, Bitwat.ch is a site that sends you alerts via e-mail when the price of Bitcoin rises above or drops below a certain price of your choosing. Bitwat.ch gets its data from CoinDesk‘s Bitcoin price tracker.

Bitwat.ch

You can also register on Bitwat.ch if you want to keep track of all your alerts. Registering also lets you delete alerts, which can be useful if the price levels you set have been made out of date, or if you’re just tired of receiving alerts.



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Selasa, 25 Maret 2014

Enter The Blockchain: How Bitcoin Can Turn The Cloud Inside Out

Drop whatever you’re doing and go read Maciej CegÅ‚owski’s absolutely magnificent essay Our Comrade The Electron, an astonishing history of the amazing Russian engineer Lev Sergeyevich Termen. Make sure you read right down to its punchline, “the most badass answer imaginable.” But if time is short, or you struggle to read English, please at least read its angry rant, from which I quote:

Technology concentrates power.

In the 90′s, it looked like the Internet might be an exception, that it could be a decentralizing, democratizing force … but those days are gone … What upsets me, what really gets my goat, is that we did it because it was the easiest thing to do … Making things ephemeral is hard. Making things distributed is hard. Making things anonymous is hard. Coming up with a sane business model is really hard—I get tired just thinking about it.

We put so much care into making the Internet resilient from technical failures, but make no effort to make it resilient to political failure. We treat freedom and the rule of law like inexhaustible natural resources, rather than the fragile and precious treasures that they are. And now, of course, it’s time to make the Internet of Things, where we will connect everything to everything else, and build cool apps on top, and nothing can possibly go wrong.

He’s right. And so the Internet has, for most intents and purposes, evolved into a landscape dominated by centralized systems, epitomized by what Bruce Sterling calls the Stacks — Amazon, Apple, Facebook, Google, Microsoft. To quote, er, myself:

They don’t want much, those Stacks. Just your identity, your allegiance, and all of your data. Just to be your sole provider of messaging, media, merchandise, and metadata. Just to take part in as much of your online existence as they possibly can, and maybe to one day mediate your every interaction with the world around you, online or off.

The Stacks exist in part because less centralized systems are extremely difficult to build. Consider, for instance, Google+ architect Yonatan Zunger’s explanation of “distributed consensus,” i.e. the means by which data can be safely preserved in distributed systems with multiple editors. It’s absolutely brilliant — but none of its 8,000 words are wasted. The gold-standard “Paxos” algorithm is sufficiently complex that a pair of Stanford engineers recently published a paper entitled “In Search Of An Understandable Consensus Algorithm” (PDF) — the title of which sums up the state of the art nicely — in which they present a new alternative, “Raft.”

Distributed algorithms, distributed data, distributed systems, distributed security: messy, tricky, complicated, a maze of vibrating tightropes stretched across an N-dimensional pit full of hungry failure modes with sharp teeth. Hard stuff.

But not impossible.

Just ask Satoshi Nakamoto.

Beyond the hype and the greed, Bitcoin is powered by a genuine technical breakthrough(1), to a degree I did not properly appreciate when I first started writing about it. The “blockchain” — the engine on which Bitcoin is built — is a new kind of distributed consensus system that allows transactions, or other data, to be securely stored and verified without any centralized authority at all, because (to grossly oversimplify) they are validated by the entire network. Those transactions don’t have to be financial; that data doesn’t have to be money. The engine that powers Bitcoin can be used for a whole array of other applications…

…with one huge caveat. As Michael Nielsen puts it, in his excellent, detailed explanation of how Bitcoin actually works:

For [the blockchain] to have any chance of succeeding, network users need an incentive to help validate transactions. Without such an incentive, they have no reason to expend valuable computational power, merely to help validate other people’s transactions. And if network users are not willing to expend that power, then the whole system won’t work. The solution to this problem is to reward people who help validate transactions.

Satoshi Nakamoto’s genius was twofold; technically, he built the world’s first(1) blockchain; socially, he lured people into powering it, using good old filthy lucre as an incentive. Which was very effective, but is now also a little awkward, as Bitcoin-as-a-currency has attracted a large number of … er … let’s diplomatically call them “colorful personalities,” and also, money-as-a-store-of-value is one field where in fact you probably do want some centralized authority, or at least insurance. I agree with the mordant observations on Twitter that it’s highly amusing watching the extremist fringes of the Bitcoin community slowly rediscover from first principles exactly why financial regulation exists in the first place.

Meanwhile, though, the noise and smoke of the ongoing endless (and endlessly entertaining) Bitcoin sturm und drang has — ironically — obscured its real breakthrough; the blockchain.

You see, it’s not that hard to imagine other blockchain-based systems which aren’t currencies and don’t attract as many “colorful personalities.” Suppose you replaced the Internet’s centralized Domain Name System with a blockchain for Internet names (like Namecoin) such that every DNS request included some proof-of-work effort. Or you used any blockchain (including Bitcoin’s) as a notary service. Or you built a new blockchain for crowdfunding. Or you replaced a centralized system which absolutely does need to be scrapped — that horrific barrel of worms known as TLS/SSL Certificate Authorities — with a blockchain-based solution powered at the browser level.

Or you built a new distributed email service, with a blockchain for email addresses, and every time you checked your email you contributed to the network. Or a new distributed social network, with a blockchain verifying identities, powered by code that ran every time its users launched its app or visited its web page.

(Technical note: this would obviously be a far more diffuse and granular system than Bitcoin’s, which runs on machines generally devoted 24/7 to mining. I don’t think that would require substantive changes to the algorithm, but while I’m a pretty good engineer I’m not an expert. That said, there’s no reason why a large number of relatively ephemeral clients would be fundamentally incompatible with a Hashcash-esque proof-of-work system, though I guess you might need a smaller subnet of persistent “supernodes” to maintain the blockchain.)

To be clear, I’m not suggesting that some smart startup might turn around tomorrow and replace Gmail or Facebook with a blockchain-powered solution. But I am saying that some indeterminate number of years hence, as bandwidth improves, and processors grow ever more powerful, and storage gets ever cheaper, it’s not inconceivable that those massive server farms could be replaced, not with a “personal cloud” — a bad idea for many reasons — but by massive distributed peer-to-peer networks: open-source, encrypted end-to-end, and orchestrated in part by blockchains. I’m saying that I can at least envision, albeit vaguely, the decline of the Stacks. Which if you look at the Internet today seems like a pretty striking and revolutionary thing to say.

For what it’s worth, I’m by no means alone in left field shouting that the blockchain is a big deal; heck, just look at Andreessen Horowitz over the last few months. And it seems likely that the blockchain, and Raft, and Spanner, and that great granddaddy of distributed peer-to-peer data called BitTorrent, are only the beginning; I expect more and more distributed-computing breakthroughs of comparable magnitude over the next decade, as the world’s searchlight minds turn to the forthcoming Internet Of Things.

Last year I argued that “The Internet: we’re doing it wrong.” Now, though, only six months later, I see traces and hints that we’re finally making the first faltering motions towards doing it right. BitTorrent is thirteen years old, but it has only just now been done right (at least for pirates) in the form of Popcorn Time. Raft might be, in a sense, Paxos done right. Threadable looks like group communications done right (and, again, distributed, at least to the extent that email is distributed.) Keybase.io seems like a step towards PGP done right. TextSecure is cross-platform end-to-end-encrypted messaging done right.

Maybe, just maybe, our online future is actually bright, and peer-to-peer, and encrypted end-to-end, and maybe even open-source and far less overtly commercial than today — and built, in part, on blockchains.


(1)You can argue that it’s more a synthesis of previous theoretical breakthroughs than a completely new invention; whatever, I don’t care.

Jumat, 21 Maret 2014

Mt.Gox Finds 200,000 Bitcoin In An “Old-Format” Digital Wallet

Mt.Gox, the bankrupt online currency exchange, said that it has located 200,000 bitcoin in a digital wallet. In a filing, CEO Mark Karpeles disclosed that the currency, which is worth about $118 million at current exchange rates, was discovered in one of the “old-format wallets” that Mt.Gox had used in the past and assumed no longer held any bitcoins.

The wallets were rescanned after Mt.Gox applied for a civil rehabilitation procedure in Tokyo District Court earlier this month. After the 200,000 bitcoin were discovered, Mt.Gox then moved them to offline wallets. As Coindesk notes, this happened around the time large amounts of bitcoin handled by Mt.Gox that had previously been dormant started moving on the block chain.

The recovered 200,000 bitcoin brings Mt.Gox’s total loss down to 650,000 bitcoin, but that doesn’t help the exchange’s customers, who are not considered creditors and therefore won’t receive any repayments if Mt.Gox decides to sell assets. As Fortune notes, the only way for most Mt.Gox customers who lost bitcoin to regain any of their money is to file a lawsuit.

Rabu, 12 Maret 2014

Bitcoin Is Not A Currency to take a cold shower, drink some coffee, and sober up

Bitcoin Is Not A Currency to take a cold shower, drink some coffee, and sober up


Goldman Sachs thinks that bitcoin believers need to take a cold bathe, drink some coffee, and sober up.

banker-bitcoin

Selasa, 28 Januari 2014

University of Cumbria to Accept money Bitcoin for Tuition Fee Payment

The College of Cumbria has become the world's first public educational establishment to simply accept bitcoin as fee for tuition fees.

bitcoin