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The Nexus FAQ - part 1

Full formatted version: https://docs.google.com/document/d/16KKjVjQH0ypLe00aoTJ_hZyce7RAtjC5XHom104yn6M/
 

Nexus 101:

  1. What is Nexus?
  2. What benefits does Nexus bring to the blockchain space?
  3. How does Nexus secure the network and reach consensus?
  4. What is quantum resistance and how does Nexus implement this?
  5. What is Nexus’ Unified Time protocol?
  6. Why does Nexus need its own satellite network?
 

The Nexus Currency:

  1. How can I get Nexus?
  2. How much does a transaction cost?
  3. How fast does Nexus transfer?
  4. Did Nexus hold an ICO? How is Nexus funded?
  5. Is there a cap on the number of Nexus in existence?
  6. What is the difference between the Oracle wallet and the LLD wallet?
  7. How do I change from Oracle to the LLD wallet?
  8. How do I install the Nexus Wallet?
 

Types of Mining or Minting:

  1. Can I mine Nexus?
  2. How do I mine Nexus?
  3. How do I stake Nexus?
  4. I am staking with my Nexus balance. What are trust weight, block weight and stake weight?
 

Nexus 101:

1. What is Nexus (NXS)?
Nexus is a digital currency, distributed framework, and peer-to-peer network. Nexus further improves upon the blockchain protocol by focusing on the following core technological principles:
Nexus will combine our in-development quantum-resistant 3D blockchain software with cutting edge communication satellites to deliver a free, distributed, financial and data solution. Through our planned satellite and ground-based mesh networks, Nexus will provide uncensored internet access whilst bringing the benefits of distributed database systems to the world.
For a short video introduction to Nexus Earth, please visit this link
 
2. What benefits does Nexus bring to the blockchain space?
As Nexus has been developed, an incredible amount of time has been put into identifying and solving several key limitations:
Nexus is also developing a framework called the Lower Level Library. This LLL will incorporate the following improvements:
For information about more additions to the Lower Level Library, please visit here
 
3. How does Nexus secure the network and reach consensus?
Nexus is unique amongst blockchain technology in that Nexus uses 3 channels to secure the network against attack. Whereas Bitcoin uses only Proof-of-Work to secure the network, Nexus combines a prime number channel, a hashing channel and a Proof-of-Stake channel. Where Bitcoin has a difficulty adjustment interval measured in weeks, Nexus can respond to increased hashrate in the space of 1 block and each channel scales independently of the other two channels. This stabilizes the block times at ~50 seconds and ensures no single channel can monopolize block production. This means that a 51% attack is much more difficult to launch because an attacker would need to control all 3 channels.
Every 60 minutes, the Nexus protocol automatically creates a checkpoint. This prevents blocks from being created or modified dated prior to this checkpoint, thus protecting the chain from malicious attempts to introduce an alternate blockchain.
 
4. What is quantum resistance and how does Nexus implement it?
To understand what quantum resistance is and why it is important, you need to understand how quantum computing works and why it’s a threat to blockchain technology. Classical computing uses an array of transistors. These transistors form the heart of your computer (the CPU). Each transistor is capable of being either on or off, and these states are used to represent the numerical values 1 and 0.
Binary digits’ (bits) number of states depends on the number of transistors available, according to the formula 2n, where n is the number of transistors. Classical computers can only be in one of these states at any one time, so the speed of your computer is limited to how fast it can change states.
Quantum computers utilize quantum bits, “qubits,” which are represented by the quantum state of electrons or photons. These particles are placed into a state called superposition, which allows the qubit to assume a value of 1 or 0 simultaneously.
Superposition permits a quantum computer to process a higher number of data possibilities than a classical computer. Qubits can also become entangled. Entanglement makes a qubit dependant on the state of another, enabling quantum computing to calculate complex problems, extremely quickly.
One such problem is the Discrete Logarithm Problem which elliptic curve cryptography relies on for security. Quantum computers can use Shor’s algorithm to reverse a key in polynomial time (which is really really really fast). This means that public keys become vulnerable to quantum attack, since quantum computers are capable of being billions of times faster at certain calculations. One way to increase quantum resistance is to require more qubits (and more time) by using larger private keys:
Bitcoin Private Key (256 bit) 5Kb8kLf9zgWQnogidDA76MzPL6TsZZY36hWXMssSzNydYXYB9KF
Nexus Private Key (571 bit) 6Wuiv513R18o5cRpwNSCfT7xs9tniHHN5Lb3AMs58vkVxsQdL4atHTF Vt5TNT9himnCMmnbjbCPxgxhSTDE5iAzCZ3LhJFm7L9rCFroYoqz
Bitcoin addresses are created by hashing the public key, so it is not possible to decrypt the public key from the address; however, once you send funds from that address, the public key is published on the blockchain rendering that address vulnerable to attack. This means that your money has higher chances of being stolen.
Nexus eliminates these vulnerabilities through an innovation called signature chains. Signature chains will enable access to an account using a username, password and PIN. When you create a transaction on the network, you claim ownership of your signature chain by revealing the public key of the NextHash (the hash of your public key) and producing a signature from the one time use private key. Your wallet then creates a new private/public keypair, generates a new NextHash, including the corresponding contract. This contract can be a receive address, a debit, a vote, or any other type of rule that is written in the contract code.
This keeps the public key obscured until the next transaction, and by divorcing the address from the public key, it is unnecessary to change addresses in order to change public keys. Changing your password or PIN code becomes a case of proving ownership of your signature chain and broadcasting a new transaction with a new NextHash for your new password and/or PIN. This provides the ability to login to your account via the signature chain, which becomes your personal chain within the 3D chain, enabling the network to prove and disprove trust, and improving ease of use without sacrificing security.
The next challenge with quantum computers is that Grover’s algorithm reduces the security of one-way hash function by a factor of two. Because of this, Nexus incorporates two new hash functions, Skein and Keccak, which were designed in 2008 as part of a contest to create a new SHA3 standard. Keccak narrowly defeated Skein to win the contest, so to maximize their potential Nexus combines these algorithms. Skein and Keccak utilize permutation to rotate and mix the information in the hash.
To maintain a respective 256/512 bit quantum resistance, Nexus uses up to 1024 bits in its proof-of-work, and 512 bits for transactions.
 
5. What is the Unified Time protocol?
All blockchains use time-stamping mechanisms, so it is important that all nodes operate using the same clock. Bitcoin allows for up to 2 hours’ discrepancy between nodes, which provides a window of opportunity for the blockchain to be manipulated by time-related attack vectors. Nexus eliminates this vulnerability by implementing a time synchronization protocol termed Unified Time. Unified Time also enhances transaction processing and will form an integral part of the 3D chain scaling solution.
The Unified Time protocol facilitates a peer-to-peer timing system that keeps all clocks on the network synchronized to within a second. This is seeded by selected nodes with timestamps derived from the UNIX standard; that is, the number of seconds since January 1st, 1970 00:00 UTC. Every minute, the seed nodes report their current time, and a moving average is used to calculate the base time. Any node which sends back a timestamp outside a given tolerance is rejected.
It is important to note that the Nexus network is fully synchronized even if an individual wallet displays something different from the local time.
 
6. Why does Nexus need its own satellite network?
One of the key limitations of a purely electronic monetary system is that it requires a connection to the rest of the network to verify transactions. Existing network infrastructure only services a fraction of the world’s population.
Nexus, in conjunction with Vector Space Systems, is designing communication satellites, or cubesats, to be launched into Low Earth Orbit in 2019. Primarily, the cubesat mesh network will exist to give Nexus worldwide coverage, but Nexus will also utilize its orbital and ground mesh networks to provide free and uncensored internet access to the world.
 

The Nexus Currency (NXS):

1. How can I get Nexus?
There are two ways you can obtain Nexus. You can either buy Nexus from an exchange, or you can run a miner and be rewarded for finding a block. If you wish to mine Nexus, please follow our guide found below.
Currently, Nexus is available on the following exchanges:
Nexus is actively reaching out to other exchanges to continue to be listed on cutting edge new financial technologies..
 
2. How much does a transaction cost?
Under Nexus, the fee structure for making a transaction depends on the size of your transaction. A default fee of 0.01 NXS will cover most transactions, and users have the option to pay higher fees to ensure their transactions are processed quickly.
When the 3D chain is complete and the initial 10-year distribution period finishes, Nexus will absorb these fees through inflation, enabling free transactions.
 
3. How fast does Nexus transfer?
Nexus reaches consensus approximately every ~ 50 seconds. This is an average time, and will in some circumstances be faster or slower. NXS currency which you receive is available for use after just 6 confirmations. A confirmation is proof from a node that the transaction has been included in a block. The number of confirmations in this transaction is the number that states how many blocks it has been since the transaction is included. The more confirmations a transaction has, the more secure its placement in the blockchain is.
 
4. Did Nexus hold an ICO? How is Nexus funded?
The Nexus Embassy, a 501(C)(3) not-for-profit corporation, develops and maintains the Nexus blockchain software. When Nexus began under the name Coinshield, the early blocks were mined using the Developer and Exchange (Ambassador) addresses, which provides funding for the Nexus Embassy.
The Developer Fund fuels ongoing development and is sourced by a 1.5% commission per block mined, which will slowly increase to 2.5% after 10 years. This brings all the benefits of development funding without the associated risks.
The Ambassador (renamed from Exchange) keys are funded by a 20% commission per block reward. These keys are mainly used to pay for marketing, and producing and launching the Nexus satellites.
When Nexus introduces developer and ambassador contracts, they will be approved, denied, or removed by six voting groups namely: currency, developer, ambassador, prime, hash, and trust.
Please Note: The Nexus Embassy reserves the sole right to trade, sell and or use these funds as required; however, Nexus will endeavor to minimize the impact that the use of these funds has upon the NXS market value.
 
5. Is there a cap on the number of NXS in existence?
After an initial 10-year distribution period ending on September 23rd, 2024, there will be a total of 78 million NXS. Over this period, the reward gradient for mining Nexus follows a decaying logarithmic curve instead of the reward halving inherent in Bitcoin. This avoids creating a situation where older mining equipment is suddenly unprofitable, encouraging miners to continue upgrading their equipment over time and at the same time reducing major market shocks on block halving events.
When the distribution period ends, the currency supply will inflate annually by a maximum of 3% via staking and by 1% via the prime and hashing channels. This inflation is completely unlike traditional inflation, which degrades the value of existing coins. Instead, the cost of providing security to the blockchain is paid by inflation, eliminating transaction fees.
Colin Cantrell - Nexus Inflation Explained
 
6. What is the difference between the LLD wallet and the Oracle wallet?
Due to the scales of efficiency needed by blockchain, Nexus has developed a custom-built database called the Lower Level Database. Since the development of the LLD wallet 0.2.3.1, which is a precursor to the Tritium updates, you should begin using the LLD wallet to take advantage of the faster load times and improved efficiency.
The Oracle wallet is a legacy wallet which is no longer maintained or updated. It utilized the Berkeley DB, which is not designed to meet the needs of a blockchain. Eventually, users will need to migrate to the LLD wallet. Fortunately, the wallet.dat is interchangeable between wallets, so there is no risk of losing access to your NXS.
 
7. How do I change from Oracle to the LLD wallet?
Step 1 - Backup your wallet.dat file. You can do this from within the Oracle wallet Menu, Backup Wallet.
Step 2 - Uninstall the Oracle wallet. Close the wallet and navigate to the wallet data directory. On Windows, this is the Nexus folder located at %APPDATA%\Nexus. On macOS, this is the Nexus folder located at ~/Library/Application Support/Nexus. Move all of the contents to a temporary folder as a backup.
Step 3 - Copy your backup of wallet.dat into the Nexus folder located as per Step 2.
Step 4 - Install the Nexus LLD wallet. Please follow the steps as outlined in the next section. Once your wallet is fully synced, your new wallet will have access to all your addresses.
 
8. How do I install the Nexus Wallet?
You can install your Nexus wallet by following these steps:
Step 1 - Download your wallet from www.nexusearth.com. Click the Downloads menu at the top and select the appropriate wallet for your operating system.
Step 2 - Unzip the wallet program to a folder. Before running the wallet program, please consider space limitations and load times. On the Windows OS, the wallet saves all data to the %APPDATA%\Nexus folder, including the blockchain, which is currently ~3GB.
On macOS, data is saved to the ~/Library/Application Support/Nexus folder. You can create a symbolic link, which will allow you to install this information in another location.
Using Windows, follow these steps:
On macOS, follow these steps:
Step 3 (optional) - Before running the wallet, we recommend downloading the blockchain database manually. Nexus Earth maintains a copy of the blockchain data which can save hours from the wallet synchronization process. Please go to www.nexusearth.com and click the Downloads menu.
Step 4 (optional) - Extract the database file. This is commonly found in the .zip or .rar format, so you may need a program like 7zip to extract the contents. Please extract it to the relevant directory, as outlined in step 2.
Step 5 - You can now start your wallet. After it loads, it should be able to complete synchronization in a short time. This may still take a couple of hours. Once it has completed synchronizing, a green check mark icon will appear in the lower right corner of the wallet.
Step 6 - Encrypt your wallet. This can be done within the wallet, under the Settings menu. Encrypting your wallet will lock it, requiring a password in order to send transactions.
Step 7 - Backup your wallet.dat file. This can be done from the File menu inside the wallet. This file contains the keys to the addresses in your wallet. You may wish to keep a secure copy of your password somewhere, too, in case you forget it or someone else (your spouse, for example) ever needs it.
You should back up your wallet.dat file again any time you create – or a Genesis transaction creates (see “staking” below) – a new address.
 

Types of Mining or Minting:

1.Can I mine Nexus?
Yes, there are 2 channels that you can use to mine Nexus, and 1 channel of minting:
Prime Mining Channel
This mining channel looks for a special prime cluster of a set length. This type of calculation is resistant to ASIC mining, allowing for greater decentralization. This is most often performed using the CPU.
Hashing Channel
This channel utilizes the more traditional method of hashing. This process adds a random nonce, hashes the data, and compares the resultant hash against a predetermined format set by the difficulty. This is most often performed using a GPU.
Proof of Stake (nPoS)
Staking is a form of mining NXS. With this process, you can receive NXS rewards from the network for continuously operating your node (wallet). It is recommended that you only stake with a minimum balance of 1000 NXS. It’s not impossible to stake with less, but it becomes harder to maintain trust. Losing trust resets the interest rate back to 0.5% per annum.
 
2. How do I mine Nexus?
As outlined above, there are two types of mining and 1 proof of stake. Each type of mining uses a different component of your computer to find blocks, the CPU or the GPU. Nexus supports CPU and GPU mining on Windows only. There are also third-party macOS builds available.
Please follow the instructions below for the relevant type of miner.
 
Prime Mining:
Almost every CPU is capable of mining blocks on this channel. The most effective method of mining is to join a mining pool and receive a share of the rewards based on the contribution you make. To create your own mining facility, you need the CPU mining software, and a NXS address. This address cannot be on an exchange. You create an address when you install your Nexus wallet. You can find the related steps under How Do I Install the Nexus Wallet?
Please download the relevant miner from http://nexusearth.com/mining.html. Please note that there are two different miner builds available: the prime solo miner and the prime pool miner. This guide will walk you through installing the pool miner only.
Step 1 - Extract the archive file to a folder.
Step 2 - Open the miner.conf file. You can use the default host and port, but these may be changed to a pool of your choice. You will need to change the value of nxs_address to the address found in your wallet. Sieve_threads is the number of CPU threads you want to use to find primes. Ptest_threads is the number of CPU threads you want to test the primes found by the sieve. As a general rule, the number of threads used for the sieve should be 75% of the threads used for testing.
It is also recommended to add the following line to the options found in the .conf file:
"experimental" : "true"
This option enables the miner to use an improved sieve algorithm which will enable your miner to find primes at a faster rate.
Step 3 - Run the nexus_cpuminer.exe file. For a description of the information shown in this application, please read this guide.
 
Hashing:
The GPU is a dedicated processing unit housed on-board your graphics card. The GPU is able to perform certain tasks extremely well, unlike your CPU, which is designed for parallel processing. Nexus supports both AMD and Nvidia GPU mining, and works best on the newer models. Officially, Nexus does not support GPU pool mining, but there are 3rd party miners with this capability.
The latest software for the Nvidia miner can be found here. The latest software for the AMD miner can be found here. The AMD miner is a third party miner. Information and advice about using the AMD miner can be found on our Slack channel. This guide will walk you through the Nvidia miner.
Step 1 - Close your wallet. Navigate to %appdata%\Nexus (~/Library/Application Support/Nexus on macOS) and open the nexus.conf file. Depending on your wallet, you may or may not have this file. If not, please create a new txt file and save it as nexus.conf
You will need to add the following lines before restarting your wallet:
Step 2 - Extract the files into a new folder.
Step 3 - Run the nexus.bat file. This will run the miner and deposit any rewards for mining a block into the account on your wallet.
For more information on either Prime Mining or Hashing, please join our Slack and visit the #mining channel. Additional information can be found here.
 
3. How do I stake Nexus?
Once you have your wallet installed, fully synchronized and encrypted, you can begin staking by:
After you begin staking, you will receive a Genesis transaction as your first staking reward. This establishes a Trust key in your wallet and stakes your wallet balance on that key. From that point, you will periodically receive additional Trust transactions as further staking rewards for as long as your Trust key remains active.
IMPORTANT - After you receive a Genesis transaction, backup your wallet.dat file immediately. You can select the Backup Wallet option from the File menu, or manually copy the file directly. If you do not do this, then your Nexus balance will be staked on the Trust key that you do not have backed up, and you risk loss if you were to suffer a hard drive failure or other similar problem. In the future, signature chains will make this precaution unnecessary.
 
4. I am staking with my Nexus balance. What are interest rate, trust weight, block weight, and stake weight?
These items affect the size and frequency of staking rewards after you receive your initial Genesis transaction. When staking is active, the wallet displays a clock icon in the bottom right corner. If you hover your mouse pointer over the icon, a tooltip-style display will open up, showing their current values.
Please remember to backup your wallet.dat file (see question 3 above) after you receive a Genesis transaction.
Interest Rate - The minting rate at which you will receive staking rewards, displayed as an annual percentage of your NXS balance. It starts at 0.5%, increasing to 3% after 12 months. The rate increase is not linear but slows over time. It takes several weeks to reach 1% and around 3 months to reach 2%.
With this rate, you can calculate the average amount of NXS you can expect to receive each day for staking.
Trust Weight - An indication of how much the network trusts your node. It starts at 5% and increases much more quickly than the minting (interest) rate, reaching 100% after one month. Your level of trust increases your stake weight (below), thus increasing your chances of receiving staking transactions. It becomes easier to maintain trust as this value increases.
Block Weight - Upon receipt of a Genesis transaction, this value will begin increasing slowly, reaching 100% after 24 hours. Every time you receive a staking transaction, the block weight resets. If your block weight reaches 100%, then your Trust key expires and everything resets (0.5% interest rate, 5% trust weight, waiting for a new Genesis transaction).
This 24-hour requirement will be replaced by a gradual decay in the Tritium release. As long as you receive a transaction before it decays completely, you will hold onto your key. This change addresses the potential of losing your trust key after months of staking simply because of one unlucky day receiving trust transactions.
Stake Weight - The higher your stake weight, the greater your chance of receiving a transaction. The exact value is a derived by a formula using your trust weight and block weight, which roughly equals the average of the two. Thus, each time you receive a transaction, your stake weight will reset to approximately half of your current level of trust.
submitted by scottsimon36 to nexusearth [link] [comments]

Lore v2 QT on Raspberry Pi

Hello,
 
To follow up to mindphuk's excellent piece on building the headless client on Raspberry Pi (https://www.reddit.com/blackcoin/comments/6gkjrw/wip_blackpi_a_stake_device_based_on_raspberry/), I thought if anyone was interested I'd show you how to get the full QT version running on the Pi on the Jessie with Pixel desktop. This works and has been soak tested for several days now on a standard Raspberry Pi 3. I have since added some coins and it stakes a handful of times a day.
 
Running staking Lore clients paves the way for some of the future use cases of BLK utilising the Bitcoin 0.12 (and newer) core tech, including colored coins. So I'm going to leave this one going indefinitely to kickstart the number of Lore clients staking. It's certainly not mandatory but it will be good in the longer term to have a nice distribution of Lore staking clients.
 
The cross-compile which lets you create binaries for multiple platforms didn't work for the QT version on the Pi, so there is more to do than just running the binary unfortunately, as below. There are folks working on some much cleaner solutions than this for the Pi, with a custom front end, and where you won't have to do any mucking about. That is coming soon. In the meantime, if you enjoy a fiddle with such things, here's how to get this QT client working on your Pi.
 
These instructions assume you are starting from scratch with a completely blank OS.
 
Download Jessie with Pixel from: http://downloads.raspberrypi.org/raspbian/images/raspbian-2017-07-05/2017-07-05-raspbian-jessie.zip
 
Note they have since (August 2017) released a version called 'Stretch' which does not work with this guide. I'll see if I can come up with something new for that at some point and link to it here when I have. In the meantime the guide should work with the Jessie image above.
 
Unzip the file and extract the .img file to burn it onto Fresh SD card to boot from (to be safe, use 16GB or larger), using a tool like win32diskimager or Etcher.
 
Assuming you have keyboard/mouse and monitor plugged into your pi, boot it up and the Jessie Desktop will show.
 
Before we do anything else, you should increase the default swap size on the pi, as compiling certain libraries can exhaust the RAM and get stuck otherwise. To do this, launch a Terminal window and type:
 
sudo nano /etc/dphys-swapfile 
 
and Change the CONF_SWAPSIZE from 100 to:
 
CONF_SWAPSIZE=1024 
 
Exit nano with control + x to write out the file.
 
Then, run the following to restart the swapfile manager:
 
sudo /etc/init.d/dphys-swapfile stop sudo /etc/init.d/dphys-swapfile start 
 
Now, launch the browser and download the Lore 2.12 binaries for ARM here: https://mega.nz/#!k2InxZhb!iaLhUPreA7LZqZ-Az-0StRBUshSJ82XjldPsvhGBBH4 (Version with fee fix from 6 September 2017)
 
(If you prefer to compile it yourself instead, it is possible by following the instructions in the original article by Mindphuk just taking into account this is the newer version of the Lore client than when that was written (https://github.com/janko33bd/bitcoin/releases) and the versions of Boost and the Berkeley DB need to be the same as below.)
 
Double click the zip and extract the Lore binary files. Yes, at the moment they are all called 'bitcoin', not 'blackcoin' or 'Lore' - this is because the code derives from a recent bitcoin core implementation so this has not yet been updated. You can place these wherever you like.
 
In the Terminal window, change directory to where you put the binaries, e.g.:
 
cd Downloads/lore-raspberrypi-armv7-jessie-pixel chmod +x * 
 
That marks the binaries as executable.
 
Now, we need the Boost libraries installed for any of the Lore binaries to work. The project was done with Boost 1.62.0. Unfortunately the Jessie repository only goes up to 1.55, so we need to download and build 1.62 manually on the device.
wget https://sourceforge.net/projects/boost/files/boost/1.62.0/boost_1_62_0.tar.gz/download tar -xvzf download cd boost_1_62_0 sudo ./bootstrap.sh sudo ./b2 install 
 
(This will take almost 2 hours. Have a nice cup of tea and a sit down.)
 
When I came to run the binaries, I found they couldn't find Boost. Running this command fixes that:
sudo ldconfig 
 
Now we are going to install the packages which aren't already included in the default OS installation which the binaries need in order to run:
sudo apt-get install qrencode libprotobuf-dev libevent-pthreads-2.0-5 
 
Now we need to install the Berkeley Database version 6.2.23. This is the version Lore v2 uses. Bitcoin still uses 4.8 which is 10 years old! This doesn't take too long.
wget http://download.oracle.com/berkeley-db/db-6.2.23.tar.gz tar -xvzf db-6.2.23.tar.gz cd db-6.2.23/build_unix ../dist/configure --prefix=/usr --enable-compat185 --enable-dbm --disable-static --enable-cxx 
 
I find this next section of the Berkeley instructions worked better just switching to root, which can be fudged by running sudo su before the rest:
sudo su make make docdir=/usshare/doc/db-6.2.23 install chown -v -R root:root /usbin/db_* /usinclude/db{,_185,_cxx}.h /uslib/libdb*.{so,la} /usshare/doc/db-6.2.23 
 
Now we're going to go up a couple of directories to where the binaries were:
cd ../.. 
 
Then run the client!
./bitcoin-qt 
 
And there you have it. Should hopefully end up looking a bit like this: http://imgur.com/a/eEHGa
 
Using the Bootstrap can save a while syncing. Download it at: https://www.reddit.com/blackcoin/comments/6b3imq/blackcoin_bootstrapdat_up_to_block_1631800
 
Place the bootstrap.dat file into the ~/.lore directory.
 
Run ./bitcoin-qt again, it will say 'Importing Blocks' rather than 'Synchronising with Network'. My pi sync'ed fully in about 5-6 hours.
 
If you want peace of mind that Lore will always start on bootup into the Jessie w/Pixel desktop (i.e. after a power cycle), then you need to create a .desktop file in the following place.
sudo nano ~/.config/autostart/Lore.desktop 
 
And in it, enter the following (tailoring the Exec line below to the whereabouts of your bitcoin-qt file):
[Desktop Entry] Name=Blackcoin Lore Comment=Mining without the waste Exec=/home/pi/Downloads/lore-raspberrypi-armv7-jessie-pixel/bitcoin-qt Type=Application Encoding=UTF-8 Terminal=false Categories=None; 
 
Power usage and payback time
 
After a good while leaving it going by itself, the CPU load averages got down to almost zero, all of the time. Idling, the Pi uses a bit less than 3 watts. This means it would take two weeks to use one 1Kw/h of electricity.
 
If you pay e.g. 12.5 cents a unit, that's what you'd expect this to cost to run in a fortnight. That's around $0.25 a month or $3 a year. Green and cheap and helping to secure the BLK network. I paid for the year's worth of electricity in 2 days staking with 25k BLK. Makes mining look silly, huh? ;)
 
Securing your Pi
 
With staking, your wallet needs to be unlocked and as such, the keys to your wallet are on the device. In a clean and newly installed environment as described above, and if you don't allow others to use your device and there is no other software or nasties running on it, there is no real cause for concern. However, there are some basic security precautions you can take.
 
Firstly, if you have enabled SSH and are playing with your pi across your LAN (or worse, the Internet), you should immediately change the password for the default 'pi' user (which is preconfigured to be 'raspberry'). Simply log in as normal, then type:
 
passwd 
 
You'll be prompted to enter the old and the new passwords.
 
Security by default
 
Your Pi is likely, by default, to not be exposed to incoming connections from the outside world because your router is likely generating a private address range for your LAN (192.168.x.x or 10.0.x.x or 172.x.x.x) which means all incoming connections are effectively blocked at the router anyway unless you set up a 'port forward' record to allow packets arriving on certain ports to be forwarded to a specific internal IP address.
 
As for accessing your Pi across the internet, if you have set up a port forward, this likely has security ramifications. Even basic old fashioned protocols have proven in recent times to have uncaught flaws, so it's always advisable to lock down your device as much as possible, and even if you only plan to access the Pi over your LAN, install a firewall to configure this. I used one called ufw, because it's literally an uncomplicated firewall.
 
sudo apt-get install ufw sudo ufw allow from 192.168.0.0/16 to any port 22 sudo ufw --force enable 
 
This allows just port 22 (SSH) to be open on the Pi to any device on my LAN's subnet (192.168.0.x). You can change the above to a single IP address if paranoid, or add several lines, if you want to lock it down to your LAN and a specific external static IP address (e.g. a VPN service you use). To find out what subnet your router uses, just type:
 
ifconfig 
 
and you'll see on the interface you are using (either hard wired or wifi) the 192.168 or 10. or 172. prefix. Change the above rule so it matches the first two octets correctly (e.g. 10.0.0.0/16 if you're on a 10.0. address).
 
You may already use VNC to access your Pi's desktop across your LAN, this uses port 5900. Add a line like above to lock it down to an internal address. It's not a good idea to expose this port to the wider world because those connections are not encrypted and potentially could be subjected to a MITM attack.
 
You can query the status of the firewall like this:
ufw status 
 
And of course, try connecting remotely once you change the rules to see what works. You should consult the official documentation for further options: https://help.ubuntu.com/community/UFW
 
Back up & Recovery
 
There are again many ways to tackle this so I'll just speak about my basic precautions in this regard. Don't take it as a be-all-and-end-all!
 
The wallet.dat file is the key file (literally) containing all the private/public keys and transactions. This can be found in:
 
~/.lore 
 
You can navigate there using Jessie w/Pixel's own file manager or in a terminal window (cd ~/.lore). You can copy this file or, if you'd rather keep a plain text file of all your public and private keys, use the 'dumpwallet' command in the console. In Lore, go to Help > Debug Window > Console and type 'dumpwallet myfilename' where myfilename is the file you want it to spit out with all your keys in it. This file will end up in the same place you launch bitcoin-qt from.
 
The instructions earlier on, when running Lore for the first time intentionally left out encrypting your wallet.dat file because in order for the wallet to stake upon startup, it needs to have a decrypted key already. This isn't perfect, but after a power cycle, it would never stake unless you left it decrypted. So the best practice here is as soon as the wallet.dat file has left your device, i.e. you copy it to a USB stick for example, put it in an encrypted folder or drive (or both).
 
In Windows, one way is to use Bitlocker drive encryption for the entire drive. You should follow the instructions here to encrypt your flash drive before your wallet.dat is on there, and don't forget the password!!
http://infosec.nmsu.edu/instructions-guides/how-to-enable-bitlocker-to-go-for-external-hard-drives-and-usb-flash-drives/
 
On the Mac, I use a software package called Concealer to encrypt files I store on the Mac itself: http://www.belightsoft.com/products/conceale   There are almost certainly free packages with similar functionality, I have just used that one for years.
 
Either way, if you want to just make sure your USB drive is encrypted, you can do so in one-click in Finder before you put the sensitive files on it: http://lifehacker.com/encrypt-a-usb-stick-in-finder-with-a-click-1594798016
 
Note that these disk encryption methods may mean having to access the USB stick on a PC or Mac in order to retrieve the files in the event of a disaster. Be aware this may mean exposing them to more security issues if your computer is in any way compromised or someone nefarious has access to your computer. There are more 'manual' ways of backing up and recovering, such as literally writing down private/public key pairs which this guide doesn't go into, but may suit you better if paranoid about your setup.
 
Recovery
 
The wallet.dat file has everything in it you need to recover your wallet, or if you used 'dumpwallet', the file you saved out has all the keys.
 
Wallet.dat method: Install Lore as normal then replace any auto-generated wallet.dat in ~/.lore directory with your backup. If a lot of time has elapsed and many transactions have occurred since your backup, launch lore with:
./bitcoin-qt -rescan 
 
And if that doesn't do the job, do a full reindex of the blockchain:
 
./bitcoin-qt -reindex 
 
If you used the dumpwallet command, install Lore then place the file containing all the keys that you saved out in the same directory as bitcoin-qt. In Lore, go to Help > Debug Window > Console and type 'importwallet myfilename' where myfilename is that file containing all the keys. The wallet should automatically rescan for transactions at that point and you should be good to go.
 
There are a million ways to do effective security and disaster recovery, but I hope this shows you a couple of basic precautionary ways. There are discussions about better ways to stake without compromising too much security which are happening all the time and developments in this regard will happen in time.
 
In the meantime, feel free to comment with your best practices.
 
submitted by patcrypt to blackcoin [link] [comments]

Wet blanket party: secure computing is nothing new

Time to play Devil's Advocate. With theDAO behind us for the most part and people heading back into the Ethereum waters, I've begun to revisit Ethereum project lists while hacking on my own Eth project, and it hasn't taken much time to re-developed a deep concern:
I get the distinct impression that the "blockchain" movement risks stalling out as nothing more than a buglamp for the paranoid and socially inept ... and the fear I have, as many others should be having, is that I've slipped into this same mental rut.
Some quick factoids:
If there exists market demand for a distributed "killer secure app" on a super-secure network, we likely would have seen it or aspirations for it by now. What are Dapps trying to solve? So you have your Dapp here and it's super-audit-able, super-secure, and super-anonymous. Besides altcoin and bitcoin evangelist nerds, who cares & why? If we look at blockchain as a "computing trend" and stop regarding it as a panacea, what's the punchlist of core competencies, and why will it succeed over the corpses of so many others?
The reason the Internet grew and found wide adoption was because it was open, free, and built around the idealism of knowledge sharing. In the hellscape presented by most blockchain entrepreneurs, we should be terrified of each other, distrustful of all government on all lands, and expect vast riches from taxing every last virtual human interaction done for free now on the public Internet. Yes, you call it fees, I call it a tax. A tax on the paranoid and the dumb who don't know any better.
Bottom line: a lot of what I see isn't a very good value proposition. Blockchain entrepreneurs need a new set of common talking points about why their product exists besides "secure", "trustless", "trustful", etc. The average user doesn't care about any of these things. Even worse, I now see commercial interest from IT managers throwing around the word "blockchain" and "enterprise" with no understanding about what it is or why.
Today's exercise: go back to your pitch, and redefine your narratives. The only narrative I see getting life breathed into is the one that says we're living in dangerous times ruled by bogeymen, and "decentralized" this-or-that is proffered in quasi-religious terms as the foundation for "revolution", "disruption", "leap forward". The truth is, it sounds more like medieval Europe with crypto.
From one blockchain entrepreneur to others willing to swallow their pride and face reality, I'd love to hear others chime in with their concerns and thoughts about how we can move forward and distance ourselves from common mental ruts in the blockchain space ... or at least have a good quip to return when challenged by prospective investors.
To close, I'll leave you with the bullet point in favor of blockchain tech that I keep coming back to for my own projects:
What are yours?
submitted by HardLuckLabs to ethereum [link] [comments]

Compiling classic on CentOS7 ... with wallet support?

I have set up a new server, and I want to spin up a bitcoin node on it.
$ ./configure --enable-wallet --with-gui=no (...) checking for Berkeley DB C++ headers... /usinclude/libdb/ configure: error: Found Berkeley DB other than 4.8, required for portable wallets (--with-incompatible-bdb to ignore or --disable-wallet to disable wallet functionality) (...) 
Should I chose --with-incopatible-bdb, or is it possible to backport that BerkelyDB? I do have a wallet.dat-file from v0.10.2.0-g16f4560 (!) running on EL6 that I'd like to import. Is it possible at all?
submitted by tobixen to Bitcoin_Classic [link] [comments]

如果你遇到这样的提示:configure: error: Found Berkeley DB other than 4.8, required for portable wallets 那就可以这样: ./configure --with-incompatible-bdb 如查遇到到这样的提示:checking for boostlib >= 1.20.0… configure: We could not detect the boost libraries (version 1.20 or higher). configure: error: Found Berkeley DB other than 4.8, required for portable wallets (--with-incompatible-bdb to ignore) Adding the above suggestion to configure allowed compilation, but this warning appeared: configure: WARNING: Found Berkeley DB other than 4.8; wallets opened by this build will not be portable! If you encounter configure: error: Found Berkeley DB other than 4.8, required for portable wallets (–with-incompatible-bdb to ignore), run the following command instead. You can always send your bitcoins to another wallet. 如果提示安装的DB不是4.8的版本,则使用下边的命令跳过DB的版本检测./ configure --with 1.准备工作1 )安装bitcoin需要的所有库本文直接使用apt进行install,由于没有配置yum的资源库,所以暂时不使用yum。 defaultconfigure: error: Found Berkeley DB other than 4.8, required for portable wallets (--with-incompatible-bdb to ignore or --dis... li123128的博客 > ./configure configure: error: Found Berkeley DB other than 4.8, required for portable wallets (--with-incompatible-bdb to ignore or --disable-wallet to disable wallet functionality) # 跳过BerkeleyDB的兼容性检查 > ./configure --with-incompatible-bdb

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