Categories
Uncategorized

VPN review: trust.zone

Sure, technically you don’t need a VPN when you’re a crypto enthousiast like me. However, using a VPN has a lot of benefits for the crypto-user.

The most important benefit is the fact that when you broadcast transactions, wether you’re using a full node (like bitcoin core or btcd) or an SPV wallet (like electrum or most hardware wallets), it doesn’t matter: hiding behind a VPN will decrease the odds of other people collecting your information and using analysis tools to dox you (reveal your real name).

I’ve been using trust.zone for quite a while now… I like them because:

  • They’re NOT located in one of the “fourteen eyes” countries
  • They’re not located in one of the countries that are deemed to be an “enemy of the internet”
  • They don’t log traffic
  • They don’t log DNS requests
  • They don’t log any connection data, exept the amount of bandwith you use
  • They accept BTC payments, and even give you a 10% discount if you pay with BTC instead of paypal, visa,…
  • Their PGP key is available
  • They meet PrivacyToolsIO criteria
  • They run their own DNS server
  • They support OpenVPN
  • They don’t block P2P traffic
  • AES-256 data encryption, RSA-4096 handshake encryption
  • 3 simultanious connections allowed
  • 108 servers in 30 countries
  • Linux support
  • No propriatary API’s on their website
  • A rating of their self signed SSL certificate
  • Super cheap (look for the discount coupon code at the end of this post!!!)
  • FREE trial available!
  • 10 days full refund policy

These are the reasons i’m sticking to trust.zone for the forseeable future :). Full disclosure: eventough i’m 100% happy with trust.zone, and i’ve been a loyal user of their service for more than a year, i do get payed if you decide to join their service using the link in this post šŸ˜‰

Last but not least, use code “2YEARSOFF” for an extra 10% discount. If you combine all discounts, you can get a solid VPN package as low as $64.66 for 2 years! That’s only $2.7 a month or less than 9 cents a day!!!)

Join here

Categories
bitcoin crypto currencies paper wallets Uncategorized

The enduserguide to creating, depositing to and sweeping paper wallets

Intro

A couple days ago, i tried to help a user with his paper wallet questions on bitcointalkĀ but ended up giving a big, technical explanation… A different user , correctly, pointed out that this was a nightmare for the standard user. That’s why today, i’m writing a small article on ONE of the ways to create, deposit to and sweep a paper wallet safely…

Creating a paper wallet

  • Make sure your PC is clean, make sure you have your latest OS updates, virus scanner, malware scanner, firewall,… Make sure your PC isn’t acting weird
  • Close all applications exept a clean browser
  • Download the latest sourcecode of bitaddress.org from github
  • DISCONNECT your PC from the internet, do no RECONNECT untill this tutorial explicitly says so!!!
  • Unpack the zipfile you got from github, you can use any trusted application you want for this.
  • browse the unpacked files, open bitaddress.org.html using your browser
  • It’s possible your browser will block the javascript used on this page, in internet explorer you’ll probably have to “allow blocked content”
  • move around your mouse on this page, or type some random characters into the textbox that will be shown on the page
  • once you generated enough entropy by moving your mouse/typing (the counter on the page will go to 100%), the bitaddress.org menu will appear
  • Click on the “paper wallet”-tab
  • chose the number of address and addresses per page… It’s up to you how many paper wallets you want to generate. You’re free to use Art or not, technically it doesn’t make any difference at all, If you disable art, you’ll have a dry, white paper containing all data, if you enable art, your paper wallet will look nice
  • Enable the checkbox BIP38 Encrypt? And chose a STRONG password. If you chose a strong password, your paper wallet will be allmost impossible to hack with the current state of technology. I’ve read a nice article on bitcointalk about this here. As you can read here, a paper wallet which private key was bip38 encrypted with a 5 letter password remained uncracked for over 2 years, eventough the encrypted private key and the length of the password was leaked.
  • Click on generate and wait (this step can take a couple of minutes)
  • At this point, you’ll be shown your paper wallet.
  • There are several options now: if you have a local printer, directly connected to your offline PC, you can print your paper wallets by clicking on the print-button. If you don’t have a printer directly connected to your PC, i suggest clicking the print-button and printing to a PDF-file. Worst case scenario, you can take a print-screen (Ctrl-print Screen), and paste this print-screen in your image editor (Ctrl-V). Make sure your image or pdf file are saved onto a usb stick.
  • Remove the usb-stick (in case you didn’t already print your paper wallet), close all windows and RESTART your computer
  • you can now go back online
  • It would be best to find an offline printer that can print images or pdf’s directly from your usb stick, so your paper wallet is never found on any online device
  • Restart your printer after printing your paper wallet
  • It would be wise to make at least 1 copy, since losing this paper wallet would mean losing all your funds! Laminating and storing in a cool, dry, safe place also works!!!

Depositing to a paper wallet

This one is relatively easy: the left side of your newly created paper wallet should contain the QR code of your address. Your address should also be printed clearly on your paper wallet (your address is the shortest of the 2 codes that are printed on your paper wallet, and it’s the one started with the number 1).

If you have a QR code scanner, you can scan the QR code. If you don’t have a code scanner, you can copy the address by hand… Make sure you double check this address (Capitalisation is important). I advice you to use my address validatorĀ just to be sure.

Once you have the address copied and validated, you can use this address to deposit money to… Either as a withdrawal address from an exchange or casino, or as a “pay to” address in about any wallet software you can think off.

Sweeping your paper wallet

I’m going to explain how to sweep your wallet using electrum, since i personally use either electrum or bitcoin-cli (the command line interface of bitcoin core). Since this is an enduser tutorial, i guess there is no need to explain how to use the command line to sweep a wallet, so i’ll stick to the electrum explanation šŸ˜‰

  • make sure you have the unzipped sourcecode of bitaddress.org on your pc (look at the first part of this tutorial)
  • disconnect from the internet
  • open bitaddress.org.html
  • click on wallet details
  • copy the bip38 encrypted private key from your paper wallet into the box saying “enter private key”
  • click on “view details”
  • enter the password you used when you created your paper wallet
  • click on “decrypt BIP38”
  • copy theĀ Private Key WIF (51 characters base58, starts with a 5) into a text document, save and reboot your pc
  • If you don’t already have electrum, download it here. It’s allways a good idear to check the SSL certificate AND the signature of any binary you download (especially a bitcoin wallet), but that’s a completely different tutorial.
  • If you’re new to electrum: install electrum, open electrum and follow the wizard to create a new wallet. Write down your seed words AND chose a VERY strong password
  • Once you’re done following the wizard (or when you already owned an electrum wallet), make sure you open the wallet.
  • Go to wallet => private keys => sweep
  • Copy the private key you saved in a text document into the box “enter private keys”, and click on “sweep”
  • Follow the wizard, and you’re done šŸ™‚ your paper wallet is now swept into your electrum wallet
  • Take a black, permanent market, and clearly mark your paper wallet as being used!!! Ā Keep the paper wallet, but never ever deposit any funds onto it ever again!!!
Categories
bitcoin crypto currencies mining Uncategorized

Is bitcoin mining Equal to free money printing?

Intro

I’ve been a member of the bitcoin community since a couple of years, and every couple of weeks a “newbie” comes along who thinks he can turn his PC into a magic money printing machine.
From time to time, this “newbie” already realises he has to buy an ASIC to “make money”, but it’s very rare to find a newbie that actually realises it’s pretty hard to make a living running a bitcoin mine.

This article is written as a future reference to show new users the pitfalls and dangers of bitcoin mining, so they can at least figure out if they could potentially have a shot at mining.

Do realise that this article is written on the 16th of may 2017. Everything told in this article is true at this point in time, but the total network hashrate fluctuates, because of this, the difficulty gets adjusted every ~2 weeks (actually, it’s every 2016 blocks, but this should average out to ~2 weeks). Because the difficulty changes, and the fluctuating price, this article might be obsolete in a couple of weeks/months, but i truely believe that the basic concepts will stay exactly the same.

I’m not going to get into detail why mining is important for the bitcoin network, i’m not even going to explain what mining exactly does… Do realise that mining is important, and even if you cannot make a profit while mining, buying an old ASIC and mining at a loss might be a great way to learn about the bitcoin protocol AND help to decentralise the network… Just don’t expect a positive profit at the end of the day šŸ˜‰

In detail

There are 3 different questions that pop up regularly (in many variations):

  1. How to CPU mine
  2. How to mine using a GPU
  3. How to mine with an ASIC

1 – How to cpu mine

Short answer: Don’t!!!
Why? A Xeon E5-2690 (dual) hashes at 66 Mh/s [1] (Megahash per second) while consuming 270 Watt. The fastest process in the current benchmarks is theĀ Xeon Phi 5100 which hashes at 140 Mh/s[1] (unknown power consumption). Altough this processor is already a couple years old, i highly doubt your desktop processor will perform better than this 60 core beast[2].
As a matter of fact, an i7 hashes atĀ 23.9 Mh/s [1] (unknown power consumption).

When we use a mining calculator, not accounting for any power costs, nor for a pool fee, the Xeon Phi 5100 will mineĀ 0.00002295 BTC/year at current difficulty level[3]…Ā So, if you don’t have to pay for your power, don’t have to pay for a server equipped with a Xeon Phi 5100, mine on a 0% fee pool 24/7 for a full year, you’ll make a whopping 4 cents (at current difficulty and BTC price).

If you mine with your i7, and you DO have to pay for hardware and power, you can clearly understand that your profit will be negative…

I actually did the math: an optimal setup with an i7, paying 1 cent/Kwu on a 0.5% fee pool, not paying for hardware and not accounting for the power consumed by the rest of your hardware, CPU mining will give you a negative profit of $11/year[4]. In reality, you’ll have to pay for your hardware, you’ll pay more than 1 cent/Kwu, you won’t find a 0.5% pool,… So you’ll lose even more money each second your CPU mine.

2 – How to miner using a GPU

Same answer as how to CPU mine: Don’t
Your losses won’t be as dramatic as mining on a CPU, however, at current difficulty, it’s not really possible to make a net profit.

The “best” single GPU seems to be the AMD ATIĀ 6990[1]. It is benchmarked atĀ 865 Mh/s while consuming 860 Watt.
If you don’t take any power costs or hardware costs into account, mining on a 0% fee pool at current diff and btc price, such a setup can potentially net you a whoppingĀ 0.00014178 BTC/year… That’s right, a whopping 25 cents…[5].
Offcourse, as soon as you need to pay for hardware, or power, or if you need to pay a fee, this “profit” turns negative in the blink of an eye…

3 –Ā How to mine with an ASIC

Asic mining is the only real option you currently have if you want to mine profitably.

In order to know if a certain ASIC can be mined profitably at this point in time, you need to find an asic you’d like to buy… Look up it’s specs onĀ https://en.bitcoin.it/wiki/List_of_Bitcoin_mining_ASICs
Once you have the hashrate and power consumption notted down, visit a mining calculator likeĀ http://www.coinwarz.com/calculators/bitcoin-mining-calculator/ and enter those details, as well as the price you’ll have to pay for your hardware, the power price you’ll have to pay and at least 1% pool fee. The calculator will then tell you How long it’ll take you to break even at current difficulty and bitcoin price.

Don’t let this number fool you… The difficulty is constantly rising, the price fluctuates, and it’s very well possible you won’t be able to run 24/7 without any downtime… Personally, i wouldn’t start mining if i wouldn’t break even in 4-5 months (offcourse, if you’re a risktaker, you can be happy with a much longer break even point).

Some extra info about the ASIC’s price… Don’t be fooled, the price is much higher than the amount of money you’ll pay the ASIC’s seller… The total price is the sum of:

  • The purchase cost (the price you’ll pay your seller)
  • The extra hidden cost when buying something (paypal fee, visa fee, bitcoin’s miner fee,…)
  • The shipping and handling
  • The insurance
  • The customs charge (don’t forget about this one!!!)
  • extra cabling (ASIC’s draw a lot of electricity, you might need to check your wiring and circuit breakersĀ out with a certified electrician)
  • networking (your ASIC will need to be able to connect to an online pool)
  • maybe a controller (for example, most avalon miners need a seperate controller, you might also need your own node if you want to solo mine)
  • shelving
  • cooling (1Kw of mining equipment will produce 1Kw of heat… You need to keep your mining room cool… Either natural cooling, or by installing power hungry A/C equipment)

Last but not least, you need to realise the biggest manufacturer of ASIC machines, bitmain (makes the antminer product line) has a horrible record of customer service.
A lot of bitcoin-related fora are filled with horror stories of people receiving refurbished or already-used ASIC’s when buying new equipment. There are stories of DOA’s that don’t get replaced, there is a standard 3 month guarantee,…

It’s a chinese company, and it seems they have a different warrantee standards as the ones most European and American residents are used to…

Conclusion

Mining is fun, it teaches you about the bitcoin protocol, it’s a great hobby, it helps to decentralise the network… BUT, it can only be done using an ASIC.

Even worse, if you want to make money with mining, you need to buy a latest gen ASIC AND have a super cheap electricity rate… Do all your calculations before even thinking about mining, it will save you from a big hangover afterwards!

References:

[1]Ā https://en.bitcoin.it/wiki/Non-specialized_hardware_comparison
[2]http://ark.intel.com/products/71992/Intel-Xeon-Phi-Coprocessor-5110P-8GB-1_053-GHz-60-core
[3]http://www.coinwarz.com/calculators/bitcoin-mining-calculator/?h=0.14&p=0&pc=0&pf=0.00&d=559970892890.83800000&r=12.50000000&er=1780.43200000&hc=0.00
[4]http://www.coinwarz.com/calculators/bitcoin-mining-calculator/?h=0.02&p=130&pc=0.01&pf=0.5&d=559970892890.83800000&r=12.50000000&er=1780.43200000&hc=0.00
[5]http://www.coinwarz.com/calculators/bitcoin-mining-calculator/?h=0.865&p=860&pc=0.00&pf=0&d=559970892890.83800000&r=12.50000000&er=1780.43200000&hc=0.00