Also see: Common problems and resolutions
Myths and misconceptions
Nxt is a scam because all Nxt coins are pre-mined
First, it's important to note that Nxt is a 100% Proof-of-Stake (PoS) coin. The only way to implement this form of currency is to issue all available coins in the genesis block. To do otherwise would force the implementation of some form of Proof-of-Work scheme in order to prevent attacks on the network that "fake" stake. Since the creator of Nxt wanted a 100% PoS platform, this was not a desirable course of action. Second, the term "pre-mined" is a misnomer because Nxt coins are not being mined at all. The original stakeholders in Nxt contributed Bitcoin in order to seed the creation of the 1 billion coins represented in the genesis block, and these coins were distributed among the original stakeholders. The stakeholders are expected to distribute coins by donating them, using them as "bounties" to pay for work on the coin (software, documentation, translations, support, etc.) that is done by the community. Even the creator of Nxt (BCNxt ) made an investment. The coins were not generated from nothing! Third, the creation of the genesis block was fully public, and all of the original account numbers and their assigned amounts of Nxt are visible: see https://bitcointalk.org/index.php?topic=303898.msg3652710#msg3652710
If there are no new Nxt to be mined, how do you validate the blockchain and secure the network?
Nxt is a pure Proof-of-Stake (PoS) currency. Users validate the blockchain and secure the network by running a light weight client on any computing device (even one that used to run Windows XP). For doing this users are rewarded with Nxt coin that is collected from transaction fees. In addition, the "transparent forging" feature of Nxt will penalize accounts that do not participate in the mining process by temporarily preventing them from earning transaction fees.
If all coins are in existence already, doesn't this make the original holders of Nxt very wealthy?
Potentially. The original stakeholders of Nxt all made an investment of Bitcoin to seed their holdings, however, with no promise of any kind of success or return on investment.
Doesn't this centralize the Nxt since most coins are in the hands of about 75 individuals?
Most of the original stakeholders have been distributing coins to others as donations, bounties for development and promotion, exchanges, etc. See the next section for more detail. By contrast, Bitcoin is five years old, and half of the total supply of Bitcoin is held by a little over 900 people (source ).
The original stakeholders are hoarding their coins
The genesis block contains 73 transactions, distributing all 1 billion Nxt among the original stakeholders for the platform. Analysis of the weekly balances in those accounts, performed by wesleyh, shows that the balances have all dropped significantly:
- Nov 24, 2013: 1,000,000,000
- Dec 1, 2013: 622,209,864
- Dec 8, 2013: 406,016,313
- Dec 15, 2013: 305,742,843
- Dec 22, 2013: 265,220,001
- Dec 29, 2013: 248,241,416
- Jan 5, 2014: 148,913,050
- Jan 6, 2014: 139,681,005
It is possible that coins are simply moving between accounts and are still being "held" by the original stakeholders. However, many of the stakeholders have been actively promoting the development of Nxt by providing donations and bounties to programers, debuggers, translators, and more. Details of some of these bounties and projects can be found in this Google spreadsheet and in the original stakeholders bounty discussion thread on nextcoin.org.
How divisible is Nxt?
Right now, the Nxt software supports divisibility of Nxt to two decimal places (one-hundredths, or cents), but all transactions can involve a minimum of 1 full Nxt. Since there are 1 billion Nxt available and the software is very young, divisibility is not a top priority. It can be adjusted in the future.
Why are transaction fees so high?
Currently it costs a minimum of 1 nxt to perform any action, whether it's sending Nxt, registering an alias or sending an arbitrary message. Transaction fees are necessary because no new nxt is ever created; the fees earned by forgers come entirely from transactions. And forgers need to earn fees as an incentive to keep their nodes running and hashing new transactions into the blockchain, thus securing the network.
Nxt is still in its infancy. There aren't a lot of users yet, and features are still being implemented. So the number of transactions per day is still low, but growing. As transactions, and the price of Nxt grows, transaction fees will be adjusted downwards to keep transaction costs reasonable while still sufficiently rewarding forgers. At present, the Nxt software allows each Nxt to be divided into hundredths, which means that transaction fees easily can be lowered to 0.01 Nxt.
Where can I find charts for the price of Nxt?
What is all this I hear about DDoS attacks on the network? How can I help?
The increase in popularity of Nxt and the release of new features such as the Alias System has resulted in may aspects of Nxt becoming the target for hackers. Right now, the biggest problem seems to be Distributed Denial-of-Service (DDoS) attacks aimed at public Nxt nodes. The impact of the attacks is significant: it slows down transaction processing and prevents nodes from communicating with one another. This results in problems like excessive "blockchain forking", causing many users to feel their client is "stuck" on a bad block. If you are a casual or new user of Nxt, the easiest and best thing to do right now may be to wait. The network will eventually correct itself, and the developers are actively monitoring the network to see how it behaves in response to the attacks. The development team and senior members of the Nxt community are also working on these issues. If you are committed to helping... thank you! The following actions are of use:
- Create a public node that can help support the network (note: for technically-minded people only). Find instructions here.
- DDoS protection. If you already operate a public node, contact your service provider and ask what DDoS defences you may be able to employ
- Hallmark protection. Register a hallmark on your node. This won't help right now, but new features that "protect" hallmarked nodes will be rolled out soon.
- Switch to a binary protocol. Sadly this last step requires advanced programming skills. If you are an ace-developer, hop into the Bitcointalk.org Nxt thread and offer your services.
What is the difference between the Nxt Server and Nxt Client?
The Nxt Server is the software that implements the core features of Nxt. When we talk about "version 0.4.0 of Nxt" being released, we are talking about the server. It is written in Java, and runs on a command-line interface. The Nxt Client is the web-based interface you use when interacting with Nxt at https://127.0.0.1:7875/ (or https://localhost:7875/). This client is intended to be temporary, because it is very basic. Access to it will eventually be removed altogether, once better clients are created. Developers are currently working on new clients for all platforms (even mobile devices!). It's likely that any new client software will also include the core server software so that you can easily set up and operate Nxt.
When I go to https://127.0.0.1:7875/ in my browser, I get a security warning. What does this mean?
Port 7875 in Nxt is used for secure communications, and any website that uses this protocol must provide a "digital certificate" to verify that the site is who it says it is. Nxt uses a "self-signed" certificate, which isn't seen as secure by most browsers. You can safely proceed past this warning, and use the software.
Why is the software so hard to install and use?
Hopefully the download and installation instructions can help you get your Nxt software running, but we recognize that the software and installation is not as easy-to-use as it will be. As of the time of this writing, the development team is working on the core features of the software (the server), and the Nxt has not yet officially been launched (this will happen on January 3, 2014). The Nxt client that the development team has created is a very basic web interface. Other developers are stepping up to create better Nxt clients for users. Details on these clients will be added as soon as they come available. Some "beta" clients that are being created can be found on the Nextcoin.org forum. Give them a shot, but remember that they, too, are still works-in-progress. Generally, all Nxt clients include the server, so you only have to download and install one package.
How do I uninstall Nxt?
It is very easy to remove Nxt from your system. Just stop the Nxt server (generally by closing your terminal window; you can also check your activity monitor / task manager and manually kill the "java" process), and then delete the "nxt" folder from your computer.
Where can I get source code?
Source code for the base classes of Nxt is available here. The source released is based on the 0.4.7e version of the client, and does not include advanced features such as the Alias System, Transparent Forging, or the Asset Exchange. This version of the source has also had three flaws intentionally injected into it, to encourage people to review and critique the code. Bounties are available for finding the flaws, and the flaws are in the code only – they are not in the released version of the software. Source code for additional features (the "secret sauce") in the Spring of 2014.
Why isn't the full source being released?
Within minutes of releasing the source code, two clones of Nxt were announced and began asking for investors. In addition, many of Nxt's advanced features are still being developed and are very new.
Wallet, accounts, and account balances
Where is my wallet?
Unlike Bitcoin or other altcoins, there is no local wallet with Nxt. More specifically, the coin uses a "brain wallet", which is to say that wallets are decentralized and kept on the network. When you create an account in Nxt, your secret passphrase is used to create your account number. Once your account number is generated, you can unlock it and access it by using your passphrase on any running Nxt node.
I just created an account but I don't see it in the blockchain explorer! Why?
As soon as you unlock an account with a secret passphrase, the account is created if it does not already exist. But until you send a transaction to your account, it will not appear in the blockchain (or the blockchain explorer). This is because the blockchain is a record of transactions, and not accounts. Send some Nxt to your account, and then check the blockchain again. As soon as the transaction is confirmed (which could take less than a minute), your account will begin to appear.
Is it possible for more than one password to open the same account?
There are 1077 account numbers available in Nxt but there are much larger number of possible passwords, so an obvious question is whether or not it's possible for more than one password to open the same account. The answer is no, and here's why: when you enter your secret passphrase, the resulting account number is a large, 256-bit value. Nxt takes the first one quarter of this value (64 bits) and uses it to create your "visible account ID" – your account number. In the rare case that someone enters a passphrase that results in the same 64-bit account number as an existing account, the software will forbid the passphrase and ask you to choose another one.
Can I access my wallet from another computer?
Yes! There is no wallet file in Nxt because all of the accounts are stored on the network. This is referred to as a "brain wallet". This means your account can be accessed from anywhere... but it also emphasizes the importance of using a strong passphrase, since the passphrase is the only thing that protects your coins from being accessed by others. (This authorization mechanism might be rewritten / updated / strengthened later). For security reasons, it is recommended that you only access Nxt software when it is running locally. This helps eliminate the possibility of someone intercepting and recovering your account password.
Can I print a paper wallet like I can with Bitcoin?
No. The only wallet in Nxt is the network itself -- all accounts are stored there. The only thing you need to protect is your private key, which is also your passphrase.
Is it possible to store Nxt offline?
Do coins left on the DGEX exchange earn me more Nxt by forging?
No. The DGEX coins are in the DGEX account, so that account earns Nxt by forging.
How do I get my first Nxt coin?
There are a number of ways for you to get your first Nxt coin!
- Ask for donations! As these are early days for Nxt, stakeholders are more than happy to donate small amounts of coin to help seed interest. Try posting your account information on this forum topic .
- Contribute to the community! A great deal of work needs to be done to help the Nxt community grow -- everything from contributing documentation, to promoting Nxt, to assisting with translations, to contributing code, and more. Take a look at this list of Nxt forum bounties or this list of Bitcointalk.org bounties to see what "tasks" need to be performed. Take one on, and earn some coin for your work.
- Purchase some Nxt coin on bter.com , using Bitcoin.
- Purchase some Nxt coin on DGEX.com , using Bitcoin.
- Pick up some coin by trading directly with members of the community in the Nxt Buying / Selling Thread. Most people will accept Bitcoins (BTC) for NXT. If you buy coins from someone directly, make sure you trust them, and try to break the amount in smaller groups! (Example: Trade 200 000 NXT for 1 BTC by breaking it down to 20 000 NXT/0.1 BTC packages)
- Get one free coin from this Nxt faucet.
Where can I buy Nxt coin?
Eventually the Nxt software will implement its own decentralized exchange.
How do I know my client software is authentic?
When new clients are released by the development team, they also publish an SHA256 hash of the file. This basically serves as a "digital signature" for the download. If even one byte of the software is altered or tampered with, the hash value will completely change. Because Nxt is open-source, it is easy for malicious attackers to create "fake" downloads of the software that include backdoors and other exploits.
When you download the software, you should generate an SHA256 has and verify that it matches the one that is posted by the development team. The current version of the client and it's current SHA256 has can be found near the end of this Bitcointalk.org forum post.
If you've never calculated an SHA256 hash before, here's how:
- On Windows, an online calculator is easiest: http://hash.online-convert.com/../sha256-generator
- On Mac OS X, a SHA-256 can be calculated using the openssl command in an open Terminal (the terminal is located in /Applications/Utilities). The openssl command would look something like this:
openssl sha256 [FILE_NAME]
- On GNU/Linux, the program sha256sum is standard on most versions of the OS. Using the sha256sum command in a terminal would look something like this:
Since all Nxt accounts are stored on the network, isn't it possible for someone to guess my "secret phrase" and get easy access to my coins?
This is a very important question. See our Account Security page for an in-depth answer.
In brief: This question emphasizes the importance using a strong, secure password to create your Nxt account.
If you enter a passphrase less than 30 characters long in the Nxt client, you will be warned that you are creating a security risk. A truly random string of 50 to 60 characters is a far better choice for a passphrase, and will significantly reduce the risk of someone "brute-forcing" your account or stumbling across it or happening to use exactly the same passphrase. Nxt supports 10^77 different account numbers (that's 100 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 accounts), so the range of possible passphrases is significant. You can use a site like https://howsecureismypassword.net/ to test the strength of your passphrase, and get an estimate of how long it would take a standard computer to crack it.
I've just realized I should have chosen a better password/passphrase. Can I change my password?
You cannot change your account passphrase in Nxt, because it is actually used to generate your account number. More accurately, for those of you who know a bit about public-key cryptography: your passphrase is the private key for your account, and your account number is your public key. If you would like to use a different passphrase, just create a new Nxt account using whatever passphrase you'd like. Once you've done that, use your Nxt client to send your Nxt coins to yourself – from your old account number to your new one. The transaction fee can be set to 1 coin, so it won't cost you much to make the change.
If transparent forging means that the generator of the next block is known, aren't people running Nxt software vulnerable to DDOS attacks?
This is possible. If it is a concern for you, you should run your Nxt software through a personal VPN service or Tor.
Why is it called forging instead of mining?
With Bitcoin and many other cryptocurrencies, the act of securing and verifying the blockchain results in new coins being created. With Nxt, however, all possible coins already exist, and accounts earn coins from transaction fees alone. As a result, it was felt that a new word - "forge" - was needed to describe the manner in which coins are earned.
How does forging work?
With Nxt, coins can be earned through transaction fees. After receiving Nxt, and waiting for 1440 confirmations, your Nxt software will begin to contribute to the block generation process and can earn coins for you as long as your account is "unlocked". The amount of coin you can earn is dependent upon the number of coins you hold, the total number of coins "active" on the network, and the transaction fees included in blocks on the blockchain.
What is "transparent forging"?
Nxt has implemented "transparent forging", which allows Nxt software to predict which accounts will forge upcoming blocks. This is basically done by iterating through all active accounts and seeing which one has the highest "hit". Transparent forging rapidly increases transaction processing, since the account that will forge the next block is known. Another benefit of this feature is that accounts that are due to forge, but do not, will be penalized by having their forging power temporarily reduced to zero.
Why do I have to buy Nxt coins in order to forge them?
If you´d like to own some Bitcoin, or any of the other altcoins, you have to invest in mining hardware to be able to mine some coins. With Nxt, you buy an actual amount of coins in order to start to start forging. There are no additional costs, and no expensive mining hardware is needed.
I have some coins in my account. How can I start processing transactions and forging coins?
If you are running the Nxt software on your computer, have your Nxt account unlocked, and some Nxt in your account, you will automatically begin forging Nxt! Officially, you can start processing transactions and forging Nxt once the first transaction that puts Nxt into your account is confirmed 1440 times. This usually takes about 2 days since currently blocks are generated once every 2 minutes on average, so 1440 blocks are generated every 48 hours). Once you have reached this milestone, the client user interface will show you a "timer" in the "blocks" widget that estimates how long it will be before you generate a block. This timer is just an estimate, based on the number of coins you have versus the total number of coins that are active on the network. The estimate will vary from minute to minute, and is just a guess based on your current probability of generating a block.
Do I have to leave the client open in order to forge coins?
No. Once your server is running, simply leave your account "unlocked", and then you can close your web browser.
What does it mean to "leave my account unlocked"?
When you type your secret passphrase into the Nxt client window, your account will be "unlocked" in your server software. Once it is unlocked, it will stay unlocked until you specifically lock it again, or until you stop your server. To unlock your account, access your server by opening https://127.0.0.1:7875/, clicking the padlock icon in the upper left-hand corner of the browser window, and entering your secret passphrase. Once this is done, the padlock icon will change to the "unlocked" state and your account number and balance will be displayed in green text at the top of the browser window. At this point, you can close your web browser and your account will remain unlocked on the server. Your server (computer) must still be running.
Suppose I lock my account (for example, by means of shutting down the server). The next time I unlock it, is the time I remained unlocked counted towards generating my next block?
No. Think of your chance of generating a block a little bit like entering a prize draw. When a block is being created and your account is unlocked, it is like you have one prize draw ticket in your hand for every Nxt coin you own. Everybody else who has Nxt coin also has prize draw tickets for all of their coins. Someone is going to win the prize draw, so your chance of winning depends entirely on how many tickets you have, versus the total number of tickets entered in the draw. Now, imagine that to win the prize, you also have to be in the room when the winning ticket is drawn. If your account is "locked" or your server is not running, it is as if you are not in the room – you cannot win the prize. Once a block is generated (meaning someone has won the raffle), a NEW prize draw is started, with all-new tickets, based on who is in the room when the new prize draw begins. So: you have zero chance of generating a block when your account is locked or your server is not running. And since the generation of each new block is NOT dependent on the result of previous block, you do not get any credit for the time that your account has been locked or unlocked.
How can I see if my account has forged a block?
If you forge a block and receive a reward, your client will show an incoming transaction for the amount of the reward. The source of the deposit will a block identifier instead of an account identifier. Another easy way to see how many blocks you've forged (and exactly how much Nxt you've earned from forging) is to use the Nxt blockchain explorer :
- Go to http://126.96.36.199/nxt/nxt.cgi?action=1
- In the text box on the right hand side, labeled "block or transaction or account", enter your account number and then clock the "GO" button.
- Near the top of the query result, you will see a line containing the information you want: "Mining ratio", "Blocks generated", and "Fee earned".
How much Nxt can I earn by forging, and how often will I get it?
You can start processing transactions and earning Nxt after the first amount in your account is confirmed 1440 times; then an estimate of the time before your software will forge a block will be shown at the top of the "Blocks" widget. It is very important to note that block generation is essentially a random process, so the best anyone can do is estimate how long it might be before you generate a block. In the Nxt client, you will see text that says "you can generate the next block in X days....": this is just an estimate of how long it could take to generate a block, based on your current probability. The estimate will vary from minute to minute, because the probability varies from minute to minute. Here is a mathematical walkthrough of how Nxt coins can be earned from transactions:
- Every 24 hours, there *should* be 1440 blocks added to the chain. This is based on an average block generation time of one block per minute. But current rates are just a bit ove half of that. These blocks represent transactions for the total volume of coins (1 billion)
- Your probability of forging a block depends on your share of the total number of coins that are active on the network. If all available coins (1 billion) were used for active mining, then an account balance of 694,444 NXT (1 billion divided by 1440) would mine 1 block per day. However:
- coins moved to a brand new account must wait for 1440 blocks to mature
- some owners don't bother with mining, don't leave their Nxt software running, or their Nxt software crashes, so only portion of all coins are actively mining at any point in time.
- the number of active coins on the network varies from one block to the next
- If you look at the "recent blocks widget" in the Nxt client you will see a red-white target icon in each block. If you divide 100% by the target value you'll get the portion of coins that was used for mining that block. (Note: Because blocks are generated once per minute, you should take an average value of these targets, since they fluctuate from minute to minute)
- For example, if the average target value is 400%, then only 100/400 = 25% of coins are mining blocks.
- Now you can calculate an approximate value of how many blocks you might create per day by multiplying the number of coins you own by the absolute value of the target (e.g. the absolute value of 400% = 4), and then divide by 694,444.
- For example, if you have 50,000 Nxt coins and the average value is 400%, you could forge 0.288 Nxt blocks per day, which translates to one block every 3 or 4 days.
- The number of coins you earn from finishing a block depends on the number of "fee coins" in the block. The minimum fee per trade is 1 coin, and the number of trades in a block will vary. A block can contain a maximum of 255 transactions. It is also possible for blocks to be empty.
How much Nxt do I have to have to forge 1 Nxt per day?
This is very difficult to estimate because forging is based on probability, and because of the way the proof-of-stake mechanism operates. From minute to minute the number of active coins on the network varies, so your likelihood of forging always varies. Experienced Nxt holders have observed that a balance of a few hundred thousand coins is necessary to forge blocks on a daily basis.
Can I forge Nxt more quickly by running multiple servers and multiple accounts?
No. Your ability to forge Nxt depends solely on your total account balance as a percentage of all available coins. This is what sets Nxt apart as a pure "Proof-of-Stake" cryptocurrency. CPU power, GPU (graphics processor unit) power, and the number of servers you run have no effect – in fact, you could even forge Nxt on a very old, low-power computer!
The Nxt Alias System
What is the alias system?
See the feature documentation for the Alias System for a general description
How do I create an alias?
See our How-To page on creating aliases.
How much does it cost to define an alias?
Just the transaction fee! Currently, you can set this as low as 1 Nxt. Be aware, however, that if multiple accounts request the same alias at the same time, the request with the highest specified fee will "win".
How do I know my alias has been created?
Like any other transaction in Nxt, you should wait to see that your transaction is confirmed. Your alias creation transaction will appear in your "transactions" window as a transaction involving a transfer of 0 Nxt.
Yes. You can link an unlimited number of aliases to your account.
Can I give an alias to someone else once it's been created?
The account that creates an alias "owns" it. Currently, the owner of an alias cannot be changed.
What can I alias?
Almost anything! Web links, phone numbers, email addresses, Nxt account numbers – almost any piece of text!
How do I change an alias?
As long as your account is the owner of an alias, you can change it by sending another transaction. Just choose a new definition for an alias that you've already created, and the network will change the definition from the old alias to the new one. The change will cost you a transaction fee.
Are aliases case-sensitive?
Are any aliases reserved?
Not at all. All aliases are assigned on a first-come, first-served basis.
The Arbitrary Messages System
What is a hallmark?
Simply put, a hallmark is a digital signature that "certifies" that a node, running on a specific IP address, belongs to an account. A hallmark helps the network put trust into specific Nxt nodes, relying on them more than other nodes for accurate information on blocks and transactions. Anyone can decode a node's hallmark to verify its authenticity and ownership. If you run multiple nodes, a hallmark also allows you to set a relative "weight" for each node, so that the network can allocate more traffic to nodes that have more resources.
Should I create a hallmark for myself?
If you are a casual user of Nxt, running the software on a home computer that is not always on or publicly accessible on the Internet, you probably do not need to generate a hallmark. If you are operating a public Nxt node (or multiple nodes!) and have a non-trivial balance of Nxt, however, hallmarking is strongly recommended.
How do I create a hallmark?
See this How-To page for instructions.
How do I verify/check a hallmark?
Go to your Nxt software's admin page (https://127.0.0.1:7875/../admin.html or https://localhost:7875/../admin.html) and locate the "verify hallmark" section. Enter any node's hallmark text in the entry field and click submit. The server will return a JSON object that will tell you the following things associated with the hallmark:
- Its IP address
- The date it was created
- The account that owns it
- Whether or not the hallmark is valid
What is hallmark weight and how is it used?
The "weight" parameter for a hallmark is best-used when you are running more than one public node. You can generate many hallmarks tied to the same account, and the "weight" parameter is used to determine what portion of the account's balance should be credited to each node. Nodes with higher balances are more "trusted". The portion of the balance used to calculate weight is governed by the formula (weight/Sum_of_all_weights). For example, if you have three hallmarked nodes and set the weight parameter for each node to 100, the nodes will be weighted equally. If you have three hallmarked nodes and set the weights to 100, 200, and 300, the nodes will be weighted at (100/600), (200/600), and (300/600).
If my account balance changes, do I need to regenerate my hallmark?
Since account balance is used to determine weight, does this mean the weight of the hallmark affects forging?
No. Forging and hallmarks are unrelated. Hallmarked nodes do not forge any differently than non-hallmarked nodes. From here, you may want to learn more about the Nxt client or look at common problems and resolutions!