bitcoin

Open Bitcoin ATM

Open Bitcoin ATM

This Open Bitcoin ATM might be a simply way to distribute Bitcoin in establishments that want to use it for sales. Just make sure no one walks away with the big box of cash.

“Open Bitcoin ATM is the worlds first open-source automated teller machine for education and experimentation.

Want to make one? Here’s a step by step tutorial. It takes about 7 – 10 hours to build with simple tools. Cost of components are less than $500 new but used parts can be purchased for even less on eBay.”

See the project Here

Securing Your Wallet

You should note that there aren’t actually any bitcoins stored in your wallet.

A bitcoin is really nothing more than a balance recorded in a publically shared ledger. Transactions are orders to the Bitcoin network to transfer some of your balance from your bitcoin address to someone else’s. The way you prove to the network that you own the bitcoins associated with a particular address is by signing your transactions with the private key that matches that address. Here’s what they look like:

Bitcoin Address: 12CbHSwuMVxbwdGzCZaiLnXgxFBj3YE2ax

Private Key: L32qYhUt93qg7MWUSYCUaPKS9qeaKEZquV566Qfh7wZfqqmvZZum

Without the private key, you can’t spend your bitcoins. It is this private key (or keys if you use more than one address) that is stored in your wallet. Needless to say, if your keys are lost or stolen, your bitcoins are gone forever. Hence, why you need to take precautions to prevent that from happening.

Hot Wallet vs. Cold Storage

In Bitcoin parlance a “hot wallet” is a wallet that is connected to the internet, while “cold storage” refers to wallets that are kept offline. The distinction is important because wallets that are connected to the internet are susceptible to being hacked and having the keys stolen. We’re going to talk about some steps you can take to prevent your hot wallet from being hacked, but it’s not possible to completely eliminate this risk. Cold storage, on the other hand, if done correctly eliminates the possibility that your wallet can be hacked.

As a general rule, you should treat your hot wallet very much like the real wallet that you carry around with you. You wouldn’t go walking down the street with thousands of dollars of cash in your pocket. To do so would just be asking to get mugged. Instead you might carry one or two hundred dollars tops. Certainly nothing more than you can afford to lose if you did get mugged. Hot wallets are the same way. Given the potential for theft, you don’t want to keep any more than a couple hundred dollars worth of bitcoins in a hot wallet. If you own more than that, the rest should be kept in cold storage and only removed when you actually need to spend the bitcoins. It may sound like I’m just offering up a suggestion here, but if you don’t want your bitcoins stolen, this practice should not be considered optional.

Securing Your Hot Wallet

There are three different types of wallets — software wallets, web based wallets, and mobile wallets. We’ll skip discussion of mobile wallets since they are a bit more experimental and I wouldn’t expect you to keep that many bitcoins on your phone anyway. Software wallets install on your computer and store your keys on your hard drive. For example, the windows version of the reference client, Bitcoin-Qt, stores the keys in a wallet.dat file located in the C:\Users\YourUserName\AppData\Roaming\Bitcoin directory. Any hacker attempting to steal your keys will be looking for this file. We should note that, by default, this file in unencrypted. All it takes is for a hacker to copy this file and they have your keys. Wallets will typically let you encrypt this file to protect it. In Bitcoin-Qt you can encrypt it from the settings menu.

Bitcoin-Qt When encrypting your wallet make sure you use a strong password. As you hopefully know, a brute force attack becomes exponentially more difficult as the length of your password increases. Random passwords of 12 or more characters should take hundreds of thousands of years to brute force. Some people make the mistake of picking a long word then changing some of the letters to symbols in an attempt to create a password they can remember. For example: @r3V0LuTi0n#. The problem with these type of passwords is that there are algorithms out there that will pick a word from the dictionary and check 10,000 combinations of that word per second. So while you think you’ve got a strong password, it can be broken pretty easily. There’s no substitute for plain old random characters: 8t$e2%?U(qHr3t!

Unfortunately, even encrypting your wallet file isn’t going to completely protect you. If your computer gets infected with malware that logs your keystrokes, an attacker could get the password to your wallet and steal your bitcoins. If someone is capable of hacking into your computer and stealing the wallet.dat file, he’s also likely to be able to get your password. Installing anti-virus software and keeping it up to date can help, but it isn’t foolproof.

AuthenticatorAnother option you have is to use a web based wallet such as Blockchain.info. These wallets works similarly to a software wallet except the keys are stored on a web server rather than on your hard drive. Like a software wallet, the keys are encrypted and can only be decrypted with your password.

An additional security feature that web based wallets will frequently offer is two-factor authentication. The two most popular two-factor services are Yubikey and Google Authenticator. Yubikey requires a USB drive to use while Google Authenticator requires that you download an app on your phone. Setting up a wallet with two-factor authentication is extremely easy. It may take a minute at most. Once enabled, you will be required to sign in with both your password and the two-factor validation code. You can see what Google Authenticator looks like on the right. It refreshes the validation code every 30 seconds making it impossible to brute force. If you have two factor enabled, an attacker will not only need your password, but also your cell phone or yubikey USB drive to steal your bitcoins.

While web based wallets will offer two-factor authentication as an optional service, it is NOT optional if you don’t want to get your bitcoins stolen. The history of bitcoin is replete with people who thought they didn’t need two-factor only to lose hundreds of bitcoins. Don’t be one of them — use two-factor authentication.

Blockchain.info also allows you to enter a second password that will be used for making transactions (separate from the password used to log in). This password is entered using your mouse and an on-screen keyboard to avoid keyloggers. Again, never pass up an opportunity to increase the security of your wallet. It will be worth it even it is less convenient.

Also, there is a particular type of attack that someone could attempt which involves altering the javascript that your browser downloads when it connects to the site. When you sign in, your password would be sent to the attacker allowing him to access your wallet. To prevent this, Blockchain offers Chrome and Firefox browser extensions that can be downloaded from the Chrome Web Store or Firefox add on manager and launched from the apps menu. The extension downloads the javascript onto your computer rather than loading it from the internet preventing this type of attack.

Browser Extension You can tell you’re using the extension because the Blockchain logo at the top of the page will have the Chrome logo next to it. If you don’t see the Chrome logo, don’t sign in! You really should never be logging in to your web wallet through the internet, only through the browser extension. Doing otherwise is unnecessarily putting your bitcoins at risk. Blockchain Chrome Logo On a final note, always backup your hot wallet. If your hard drive crashes or the server where your keys are stored goes down, you’ll lose your bitcoins. Most software wallets will have an option in the menu to backup your keys or you could simply copy the wallet.dat file to a flash drive, the cloud, or another computer. Web based wallets will give you an option to download a backup or have one emailed to you.

Cold Storage

Now we’re going to talk about how to securely create a cold storage wallet. Keep in mind it isn’t as simple as generating a new Bitcoin address, copying the private key to a flash drive, then deleting the key off your computer. If you do this while connected to the internet, someone could steal your keys in the window between when you generated the keys and when you deleted them from your computer. There are better options for doing this securely.

Option 1: This is the preferred method for creating a cold storage wallet. You will need a second computer that you are committed to keeping offline permanently. An old computer or laptop that you don’t use anymore will work provided that it isn’t liable to crash on you.

  1. Install the Bitcoin software on this computer.
  2. Unplug it from the internet or disable your WiFi connection. Be sure that you NEVER reconnect it after this point.
  3. Generate a new Bitcoin address and private key. With Bitcoin-Qt you can just delete the wallet.dat file and it will create a new one when you restart the software.
  4. Copy these keys to flash drives in case your computer crashes. Keep the flash drives in separate locations. You might want to hide one in your floorboards or put one in a safe deposit box.
  5. Send bitcoins from your hot wallet to the address you just generated.

By creating a cold storage address this way, you can guarantee that your private keys will never touch the internet, thus making it impossible for your keys to be stolen. That is, unless someone physically accesses your computer or flash drives. But that is why you encrypt them after all.

How you can generate a new key pair while offline. How do you know that the bitcoin address you generate isn’t already taken? The answer is there are so many possible bitcoin addresses that the probability you will generate an address that is in use by someone else (or vise versa) is remote. Put it another way, if you were generating bitcoin addresses non-stop every day, the Sun would turn into a red giant and engulf the Earth before you would stumbled across an address already in use.

Option 2: If you don’t have a second computer, there is another way of creating a cold storage wallet, but keep in mind this option doesn’t 100% guarantee that your keys won’t be stolen the way option 1 does.

  1. Disconnect from the internet and turn off your modem.
  2. Open the Bitcoin software and generate a new bitcoin address.
  3. Copy your wallet.dat file to a flash drive (or multiple flash drives)
  4. Delete the wallet file from your computer.
  5. Restart to clear your memory of any data that may be stored by malware.
  6. Reconnect to the internet and send bitcoins from your hot wallet to the new cold storage address.

While I’m not an expert on malware, I’m going to assume that it is possible for malware to copy your private keys (after you generate them offline) to your hard disk and upload them once you reconnect to the internet. I haven’t heard of this happening, but I suppose the possibility is still there.

It is possible to mitigate this risk if you want to go through the trouble of booting into another OS. If you are unaware, you can boot into temporary operating system directly from a DVD or USB drive without actually installing the OS on your computer. Doing so will isolate your work environment from any malware that you might already have on your computer. In my opinion, the best OS to use for this purpose is the Linux based Tails operating system. Tails is specially configured to not use your computer’s hard disk, only the memory. That means if you accidentally download malware while using tails, it will be erased when you reboot into your normal OS. This should prevent malware from copying your keys and broadcasting them when you finally reconnect to the internet. It may sound like booting into another OS is difficult, but it really isn’t. The Tails website has easy to follow instructions. It really amounts to little more than downloading an .iso file, burning it to a DVD, then rebooting with this DVD in your drive. It’s that simple.

I should probably also mention that Coinbase runs free hosted wallet service. They keep approximately 90% of the bitcoins their customers store with them in cold storage (safe deposit boxes to be exact) and about 10% in a hot wallet so they can spend them at their convenience. If you’re not comfortable making a cold storage wallet yourself, you might want to consider outsourcing it to them. Considering their livelihood is on the line if they fail to keep your bitcoins safe, I would say they are pretty secure. The only problem would be if the U.S. government decided to raid Coinbase, you would lose all your bitcoins. That wouldn’t happen if you store them yourself.

Paper Wallets

Instead of (or in addition to) keeping your cold storage private keys on a hard drive or flash drive, you can print them onto a piece of paper. Paper Wallet You could do this by using either options 1 or 2 from above. There are several websites that offer paper wallet generators. Blockchain.info, Bitcoinpaperwallet.com, and Bitaddress.org among others.

If you are going to use these services DO NOT just generate the paper wallet in your browser. You could be victimized by the same javascript attack I mentioned earlier. You can avoid this by using the Chrome or Firefox browser extentions if you are using Blockchain.info or by downloading the source code for the other sites from GitHub and running the script natively. If you’re paranoid that your roommate or a bank employee (if using a safe deposit box) might steal your paper wallet, you might want to consider printing it out with a BIP 38 encrypted private key.

Brainwallets

The only reason you actually need to store a private key somewhere is because it’s so difficult to memorize it. If you could memorize it, then you wouldn’t need to worry about your computer being hacked. Enter brain wallets. A brian wallet is a bitcoin wallet that is generated deterministically from an easily memorizable passphrase. For example:

Passphrase: Man made it to the moon,, and decided it stinked like yellow cheeeese.

Private Key: 5JhmqDih2bTprJLZJYwUgnsAiHNbU8DReuBFMKCq5nPAmj1PeYQ

Bitcoin Address: 1CeU9ugjwfsnzrhqjKy1HUBzXCCXVC76m1

So long as you can remember the passphrase, you can always generate the corresponding private key and bitcoin address at a time of your choosing. This would especially useful for people trying to smuggle bitcoins across international borders. You wouldn’t need to try to create a hidden partition on your hard drive or hide a flash drive on you somewhere. You could simply store your bitcoins in your head and clear customs with no problem.

Keep in mind, if you are generating a brain wallet, your passphrase needs to be much longer and much more random than a typical password.  Possibly a random sentence containing over ten words and a few unique spellings and avoid using sentences or quotes found in published literature. Also, considering adding a salt to the end of your passphrase to increase the security:

Man made it to the moon,, and decided it stinked like yellow cheeeesea4uMj92Hnlx.

Like paper wallets, there are websites you can use to generate a brainwallet: Blockchain.info, Brainwallet.org, Bitaddress.org. Just like before, you want to use options 1 or 2 for creating the brainwallet offline and either use the browser extension or download the source code from github when running the script.

Removing Bitcoins From Cold Storage

If you are trying to remove bitcoins from cold storage, you must spend the entire amount. There have been plenty of people have tried spending only part of their cold storage balance only to lose everything. To understand why this is the case, you have to understand how bitcoin transactions work. When you go to spend bitcoins, you have to prove you own the amount that you are trying to spend. Your wallet does this by pointing to a transaction in the blockchain where you received this amount bitcoins or more. This amount is considered to be the transaction “input”. As per the protocol, transaction inputs and outputs must be equal. So lets say you want to spend three bitcoins. Your wallet might use a prior transaction where you received 10 bitcoins as the input. Since outputs must equal inputs, your wallet will send three bitcoins to the destination and seven bitcoins back to yourself as “change”. Many wallets, including Bitcoin-Qt, will generate a brand new bitcoin address for the change rather than send the change back to the original address. This is considered to be an anonymity feature.

If you import your private key into your hot wallet from cold storage and make a transaction for less than the full balance, your wallet will send the change to a newly generated change address. If you assume the balance is still in your original cold storage address and proceed to delete the new wallet file, you will be deleting the keys to the change address leaving your original cold storage address with a balance of zero.

So to eliminate this possibility, always spend the entire balance from your cold storage address. If you want to keep some funds in cold storage, go through the steps for creating a new cold storage address and send the balance there. It may be more convenient to create multiple cold storage addresses, each with a balance of 5 BTC, say, rather than a single address with a balance of 100 BTC. That way you would only have to remove 5 BTC from cold storage when you want to spend it, rather than the full balance.

Offline Transactions

Instead of going through the hassle of completely removing funds from cold storage every time you want to make a transaction, there is an advanced feature that allows you to make transactions directly from cold storage. If you use a second computer for cold storage like described in option 1 above, this is how you would do it:

  1. Create an unsigned transaction sending bitcoins from your cold storage address to the destination.
  2. Transfer the unsigned transaction to the cold storage computer via a flash drive.
  3. Have the cold storage client sign the transaction using your private key.
  4. Transfer the signed transaction back to the online computer and broadcast it.

Doing it this way, you can make a transaction without exposing your private keys to the internet, eliminating the possibility of theft. Currently, the bitcoin wallet Armory is the only wallet with this feature.

Hardware Wallets Trezor

Finally, we’ll wrap up with a new technology that should be hitting the market very soon — hardware wallets. As you can gather from our discussion thus far, the most secure way to use bitcoin is to use a second computer for cold storage and offline transactions. The problem is that most people don’t have a second computer available and even if they do, it takes some technical skill to set it up properly.

A hardware wallet essentially serves as your second computer. Your bitcoin address and private key are generated entirely on the device and never come in contact with the internet.  When you want to make a transaction, the hardware wallet signs the transaction and sends it over a USB cable to your computer for broadcast. The image on the right is of the Trezor hardware wallet which is scheduled to start shipping in either October or November. Butterflylabs is apparently also working on a hardware wallet, but I’ll believe that when I see it. They are notorious for over-promising and under-delivering.

Best Bitcoin mining software

Best Bitcoin mining clients

btcminer

Are you thinking of joining the Bitcoin mining universe? In case you don’t know, you can either mine on your own or as part of a pool. In terms of profit, there aren’t really many differences: solo mining will give you large and irregular payouts, as pooled mining will result in small and frequent payouts. In the end, they both add up to the same amount.

Whatever your choice might be, remember you need to follow certain steps to successfully mine Bitcoins: get the right hardware, get the best software that matches your needs, arrange a way to receive the profits of mining and start solving algorithms.

This is where you stop and think: but what is the best software for me if I don’t even know them all? Well, let’s make a small list of the most used software and help you choose.

1. CGminer

io2po85E1jxKo

This software is, currently, the most popular GPU/FPGA/ASIC miner. CGminer is an open source GPU miner written in C available for several platforms like Windows, Linux and OS X. One of the things that make it extremely popular is the fact that it’s based on the original code Cpu Miner, which you can discover in Bitcoin Wiki.

This software includes overclocking, monitoring, fans peed control and remote interface capabilities. His other features include self detection of new blocks with a mini-database, binary loading of kernels, multi GPU support and CPU mining support. There are a lot of other characteristics you can discover here, at CGminer official forum.

Download CGminer here.

2. BFGminer

a2w652

This software is a derivative of the previous CGminer, designed specifically for FPGA and ASICs, but without the central focus on GPUs like CGminer. The latest update on BFGminer, the 3.1.1 version launched in April 2012, features dynamic clocking, monitoring and remote interface capabilities.

Besides being a super versatile program, BFGminer has really interesting features: vector support, integrated overclocking and fan control, ADL device reordering by PCI bus ID, support for mining with free Mesa/LLVM OpenCL and for getblocktemplate decentralized mining protocol and also crypt mining support for both CPU and OpenCL (GPU).

A little reminder: if you’re mining with a ModMiner, X6500 or ZTEX devices, you need to download bitstreams to make sure BFGMiner 3+ works with your device. You can find them in the official BFGminer forum and check BFGminer’s official website here.

Download BFGminer here.

3. BitMinter

carousel-getset

We can say that, although BitMinter might not be the most popular mining software, it’s certainly one of the best when it comes to connect with users and potential “clients”. The software’s official website is quite complete and straightforward: for the creators of the program, it’s all about making Bitcoin mining “easy” and winning “high payouts”.

BitMinter is different because it’s a software that belongs to a mining pool, so your initial step is to register and fill in the pool sign-up form. So, it’s a great option if you’re looking for a simple installation.

Besides being available for operative systems like Windows, Linux and Mac OS X, BitMinter assures a good mining speed and long polling in order to reduce stale work. It also allows you to mine on OpenCL-compatible GPUs or ASICs/FPGAs (BFL, Block Erupter and other Icarus-compatible). The official BitMinter forum can be found here.

4. BTCMiner

5cyvqv

This open source Bitcoin mining software for ZTEX USB-FPGA Modules 1.15 runs on the operative systems Linux and Windows. Yet, Windows users need to install the libusb driver first, which you can find here. The FPGA boards supported by BTCMiner (USB-FPGA Modules 1.15b and 1.15d, USB-FPGA Modules 1.15x and USB-FPGA Modules 1.15y.) have a USB interface, which can be used for communication and programming, allowing the user to build low cost FPGA clusters with standard components (like USB hubs, for instance). In practical terms, this means no JTAG programmer is required and the program allows to run large mining rigs from just one software instance.

The software features a ready-to-use Bitstream, which doesn’t require any Xilinx Software or a license, so this is an advantage. However, its dynamic frequency scaling is based on error measurement: so, BTCMiner automatically chooses the frequency with the highest rate of valid hashes. You can find BTCMiner official website here and discover more about this mining software.

Download BTCminer here.

5. Poclbm

Screen-Shot-2013-04-25-at-2.15.20-PM

Poclbm is a python GPU Bitcoin mining software, which uses the OpenCL framework to perform the hashing computations in a quick way. This framework, which allows programmers to write code that will work across a big variety of hardware, reveals all its potential when used with a modern GPU, producing hash rates of higher magnitude than what can be achieved with a normal CPU.

The program works perfectly with AMD – 4xxx and up, as well as with Nvidia – 8xxx and up (also video cards). According to some users talking in the official Poclbm forum, the software is great for experimentation and also multiple machine mining (not so good for the masses).

Download Poclbm here.

6. DiabloMiner

5ziRw

This program is a Java GPU Bitcoin miner that uses the OpenCL framework, like Poclbm. This way, DiabloMiner also allows its users to quickly perform the hashing computations. The software, which is a command line kind of program, works on current Nvidia drivers and ATI Stream SDK 2.1. This characteristic means that the users need to open a terminal (cmd.exe, Terminal.app/iTerm2 or xterm, among others) and run the program from there.

If you’re mining in multiple pools, it’s important to know that DiabloMiner supports unlimited pools and is able to switch to the next pool on connection failure, returning to the first one every 60 minutes, according to information available on the software’s website. To read some opinions of users go to the DiabloMiner official forum.

Download DiabloMiner here.

 

After presenting you these different software miners and its characteristics, it’s safe to say one thing: more important than rating them and placing them on a podium, you need to know them to correctly choose the one that’s better for your needs and already available hardware. If you’re looking for a technical comparison, check these tables at Bitcoin Wiki. Good mining!

Bitcoin ATMs Coming to the U.S.

 Bitcoin ATMs Coming to the U.S. BY Will Yakowicz

Austin and Seattle will get the first machines later this month, making it easier for consumers to use the virtual currency and benefiting companies that accept it.
80 SHARES

Bitcoin automated teller machiness will soon become available in the U.S., potentially increasing the customer base for businesses that accept the digital currency.

Robocoin, a Las Vegas-based startup, announced on Tuesday that it will install the first ATMs in the U.S. in Seattle and Austin by the end of February–eroding a major barrier to the virtual currency’s mainstream adoption.

The company installed the first two Bitcoin ATMs in the world last year in Vancouver and London. It plans to install additional machines this month in Asia, Canada, and, Europe, Reuters reports.

According to the wire service, the kiosks are similar to conventional cash ATMs, but instead of reading debit cards the machines scan government-issued identification cards like driver’s licenses or passports to confirm users’ identities.

Users will be able to exchange Bitcoin for cash, as well as to deposit cash to buy Bitcoin. To transfer and hold funds, users need to have a virtual wallet on their smartphone.

It’s still difficult for the average user to buy, sell, and use Bitcoin. But as startups race to make the virtual currency easier to use and popular e-commerce sites like Overstock.com–which has recorded $1 million in Bitcoin sales–start accepting it, wide adoption may be within sight.

Scott Robinson, the founder of the Sunnyvale, California-based Plug and Play Bitcoin Accelerator, says the Bitcoin ecosystem today is in a similar state to the Internet’s infrastructure when it was being built two decades ago.

“In more than one way, this is entirely paralleled to the Internet in the 1990s,” Robinson says. “If you can, remember how hard it was to just connect to the Internet in 1993: Set up an Internet provider account, buy a dial-up modem, download a browser, use the browser to find a search engine, or go straight to AOL’s homepage.”

The news of Bitcoin ATMs in the U.S. comes after a hectic period for the virtual currency, with one of the largest exchanges, Mt. Gox, freezing withdrawals due to a security breach. The price of Bitcoin plummeted from nearly $850 early in February to less than $580 on February 14. As of Tuesday morning, Bitcoin is hovering around $620.

BY Will Yakowicz

CoinURL is one of the most popular link shorteners that pays you in bitcoins

CoinURL is one of the most popular link shorteners that pays you for each visit to your readers to make them. To repay ads shown before sending your visitors to the landing page. Payment is always in bitcoins .

CoinURL Previously announced a minimum price for ads from all countries was established and became a little more
more reliable to attract new advertisers to increase and maintain security measures to prevent cheating by some site users . Now the ads are related to the usability of users of this web address shortener .

Since last Wednesday, you may access the web interface of the language CoinURL prefer , those included in the drop down list at the top left . Of course, the Castilian is present , as well as a dozen languages.

Translation errors are abundant and obvious signs of having been made ​​automatically . From CoinURL encouraged to collaborate with best translations and even apply for a new language and need it to be yours .

9 Bitcoin alternatives

Nine Bitcoin alternatives for future currency investments

Bitcoin’s rapid rise in value and profile has spawned over 60 different ‘altcoin’ digital peer-to-peer currencies
A bitcoin
Bitcoin is one of over 60 different alternative digital peer-to-peer cryptographic currencies. Photograph: Jim Urquhart/Reuters

Bitcoin’s recent meteoric rise in value to over $1,000 has shone the spotlight on alternative currencies, but bitcoin is not the only new digital currency vying for relevancy in 2013.

Like bitcoins most of these currencies are mined by computers solving hard mathematical problems. The “coins” do not exist physically, of course, as the currencies are virtual existing only as computer files.

As they are based on peer-to-peer protocols, no one computer controls the currencies, but networks keep track of all transactions made using these digital currencies, but they do not know what the coins were actually used for – just the ID of the computer “wallet” they move from and to.

Here are nine alternatives to think about before putting your time, effort and money into bitcoin.

Litecoin

Like bitcoin, litecoin is another crytography-based digital currency, which has also seen a dramatic rise in value in recent months.

Litecoin, a peer-to-peer opensource digital currency, could be described as an offshoot of bitcoin. In fact, it is based on the bitcoin protocol, but instead of requiring extraordinary computing power to mine effectively, can be mined efficiently using standard computers due to its algorithm originally designed by Dr Colin Percival for the Tarsnap secure online backup service for Linux and other opensource operating systems.

Namecoin

Also based on bitcoin, namecoin is another opensource offshoot. A cryptocurrency, namecoin also acts as a decentralised DNS – the protocol on the internet that turns human-comprehensible website names such as theguardian.com into addresses understandable by machines. By acting as its own DNS, the currency operates outside the regular internet and therefore outside the governance of the Internet Corporation for Assigned Names and Numbers (Icann).

The currency values and domain names are stored within the blockchain record, which limits the total number of namecoins to 21m, with each coin divisible down to eight decimal places.

Peercoin

Another variant of the bitcoin-like peer-to-peer currency principle, peercoin promises increased efficiency of mining, improved security and safeguards to avoid abuse by group mining, which has recently been highlighted as a potential flaw with bitcoin.

Peercoin has the fourth-largest market cap among “altcoins” as these alternative digital currencies are known, according to CoinMarketCap.com, which tracks emerging and traded currencies.

Primecoin

A cryptocurrency like bitcoin, primecoin differs at its core because it uses a totally separate mathematical basis for mining. Instead of relying on bitcoin’s “Hashcash” algorithm, primecoin finds long Cunningham chains – a certain sequence of prime numbers named after the mathematician AJC Cunningham – to build value into the currency.

Unlike bitcoin, primecoin’s mining difficulty increases slightly with each new coin created, scaling more evenly than bitcoin’s bigger shift in mining difficulty every 2016 blocks.

Feathercoin

Based upon litecoin, feathercoin adjusts its mining difficulty more often than litecoin and was announced in April 2013. Unlike some other digital currencies, feathercoin updates regularly to incorporate new features and enhancements, including protections from abuse and forking by group mining.

Novacoin

Yet another peer-to-peer digital cryptocurrency, Novacoin differs from most of the other altcoins by integrating protection schemes within the core of the currency, which deters abuse by mining groups.

Novacoin also has a technical cap of 2bn coins, a much larger number than most of the other digital currencies which top out in the millions, rather than billions of coins. The cap could also be increased if it was ever reached, giving novacoin a theoretical dynamic inflation.

Infinitecoin

Announced in June 2013, as another litecoin spin-off, infinitecoin differs with more frequent difficulty adjustment rate during mining and the total number of coins that can be created, which is 1142.86 times as many as litecoin.

Megacoin

A bitcoin analogue in its infancy, created within the fourth quarter of 2013, megacoin is limited to 42m total coins and is mined like every other crytocurrency. Each coin worth around $0.50, and its main selling point is its overt branding, something quite a few other digital currencies lack.

Quark coin

Another altcoin in its infancy, launched in 2013, Quark coin takes the security elements of the cryptocurrency very seriously employing nine separate rounds of encryption using six different algorithms.

If those nine bitcoin alternatives weren’t enough for you, there are over 60 different altcoin currencies currently being traded at various exchanges like Cryptsy, including AndroidsTokens, AlphaCoin, AmericanCoin, AnonCoin, Argentum, AsicCoin, BBQCoin, BitCar, ByteCoin, BitGem, BottleCaps, CryptoBuck, CryptogenicBullion, CopperLark, Cosmoscoin, CHNCoin, ColossusCoin, CopperBars, CraftCoin, CasinoCoi…

From: http://cur.lv/54kuk