If you are using a C1 you should make a backup of your SD card when it's working.  That's what I did and if anything went wrong you can just flash the SD card with old firmware and it was easy.

That would be my advice on it if you have a backup try it.   And if you don't make a backup and see what a new FW does.  It helps rule out software and with C1 the SD option is great in case of bricks.

The problem with this becomes were kinda at the last of this generation of miners.  And no one knows how long it will last.  Will bitfury take months? Who knows for sure.

I think timing on next generation gear could also be a factor.  Also what happens to the old gear will be a huge factor.  If they find places in world to keep it running, or if some gear like A1's finally start to come offline in big numbers.

I thought the same thing almost no one get's this priced electricity.  If you do I would ask where?  And is it a stable grid? 

But check your electricity costs as it will make or break ROI.   Also on sale it's hard to say if there is gear that comes out and is 1/4 the power needed... it could also kill your investment.   Your entering at a unusual time with difficulty.

It's not a bad wallet, but your right those should be considered.  Some that do it are there to run a node and support the "network".

But for most people a light wallet not needing the full blockchain is best.   It just depends on the user really.  I still think hardware wallets will become more and more important and used.

I don't think it's one difficulty that is a deal breaker for me, but a combination.  As they build on each other... that is what could get me.  If they keep adding up high together it will shrink profit's or possibly get rid of them. 

So I say it's the continued difficulty that adds that will get most, in my opinion.

They may look the same at first glance but they are very different.   The Ledger is a hardware wallet.   The Yubikey is a physical key for second factor authentication.  So the Yubikey has much more uses.

Some of the main uses I really liked was using it to secure a blockchain.info wallet instead of sms.   It also did great with gmail account's.  So these even if compromised an attacker needs my Yubikey to log in, which they should not have.  So great there.

And Lastpass is great addition.  It's a full program on it's own, but combines great with Yubikey to secure your passwords. 

They really are a good machine I would not let the few over volting get your attention to much.  Just stay under the 12.2 as said on BlockC's sales site  and you should be good as far as over volting.

For the most part these miners are out there working great.   But if you over volt past recommended... turn it down.

I don't know a ton about them but they are a faucet with the words "up to" in it.  Keep in mind they really do mean "up to" very few will ever win it.  Most will spend time there and get cent's.

All faucets are cent's per hours of time.  They just don't make a ton on traffic revenue, and they pay out less then they make.  So in most cases were talking about dust.

Sorry to hear about your loss Nhando.  Honestly anyone out there over volting be careful.   I would not push it over the: 12V DC ±0.2V. - http://www.blockc.co/collections/bitcoin-miners-shop-avalon-blockc-co/products/avalon6-bitcoin-miner 

I have not pushed mine at all on over volting and don't plan on doing it.  Those who have been doing it.... really think about it as it can kill your investment.

It feels weird to hope for 15... a solid double digit number.   Just much higher then I like.  Bitcoin did rise a tad today, not to point we need with jumps like this.  But I guess take what positives we can have.

Tonight not a ton of time left bitwisdom is at:

Bitcoin Difficulty:    120,033,340,651
Estimated Next Difficulty:    143,018,016,533 (+19.15%)
Adjust time:    After 385 Blocks, About 2.2 days
Hashrate(?):    1,067,233,187 GH/s

You can calculate it here with watt's and your price: https://bitcoinwisdom.com/bitcoin/calculator .  I don't think it's going to look good for you, UK is normally not a great place with miner with VAT and high electricity (in most part's at least  shared on board).

But do some ROI math.  Honestly no one can tell you how long till 7000 out of that, or if you make it to that even.  We cant tell you what next difficulty period will be.... add months to that its very hard to speculate.

All I do know is most likely you are better off shipping it to a good data center that has no VAT and probley cheaper electricity then most UK.

The next few difficulty changes could literally make or break profitability.  If 20 continues I don't see price jumping that much each difficulty period.  We honestly cannot guess what next one will be.   Just not enough good info.

All we do know is China has some holiday coming up.   So maybe they are pushing hard now, and it lowers (my hope).  Or they keep pace of making this much hash till having (my fear).

I have been trying different options out there.  This is one really to take a look at.  With using Yubikey it is a physical token that is great with Blockchain.  And it seems people use it a lot here as a hot wallet.

My worries with text might be small but I worry of someone compromising the phone, or managing being able to get it fowarded via social engineering.  With Yubikey I have full control of my physical key, which I like.   And I have in safty deposit box the secret phrase if I ever lose my Yubikey for blockchain.

On passwords I went with Lastpass as it creates great long passwords that are unique, and can be saved within 2 factor security using Yubikey with it.  So if one site is hacked and a "bad guy" gets a password it just get's him one site.  No sharing of passwords.  

The more I test it the better I feel with it.  And the Yubikey 4 Nano fits so great in a usb slot.   I was surprised how much I liked the Nano.

What aspect are you wanting them to be introduced to?   Do you have a business your trying to promote to them?  Or are you just wanting to promote bitcoin in general?

And if so in general which side? Mining? Investing? Just info behind it?  More we know better we can help.

The best USB miner is the compac.  But USB minerss are mainly for learning or lotto mining, you will not make ROI in most cases.  

For ROI it takes cheap electricity and a good price on miner.  What is a good price? Hard to say right now with current difficulty.  And the cloud services your mentioning if you go cloud just go hashnest.   Don't bother with some of the others, just to many scams out there.

Why do you think you have a short period of time for investment?  And on " ı dont thınk ı have a rısk to lose my money but to just earn lıke 100 dolars a mouth"  yes.. you will have to risk your money to earn hundreds of dollars a month.   

You have a good electricity price but do some ROI math with big changes in difficulty 1.5 years is a little optimistic.  Miners tend to change a lot just in a year.

0) Why Look into This
1) Info From Manufacture
2) The Products
3) Lastpass
4) Some Sites integrated with Yubikey Support(Including Blockchain.info!)
5) Conclusion
6) How to purchase



1) Why look into this?

Almost everyday we can see posts of someone losing their account in Meta on the forum.  This caused me to ask myself what is the reason?  And what can we do to stop it along with pushing security more.  The anwser varies from lack of good security procedures such as using same password on more than one site, to losing it to attacks including malware and phishing.

It is enough of a problem to look into possible options.  I have been using hardware wallets, and really liked the physical element added to your security.  I knew I wanted a physical key as part of my security on other security solutions, which is what brought me to Yubikey.

1) Info From Manufacture

A YubiKey is a small device that you register with a service or site that supports two-factor authentication. Two-factor authentication means that each time you log in, the service will request proof that you have your YubiKey in addition to your regular username and password. Phishing, malware, and other attack methods don’t work because they would need both your physical key and your passwords to breach your accounts.

To put it simply Yubikey is a physical key you can use to secure many of your digital assets.  This includes everything from 2 factor Gmail accounts, Blockchain.info wallets to entire storage of passwords working with programs such as LastPass.


2) The Products:


Above you will see three different Yubikey's.  I wanted to try multiple versions as the one best for you can depend on your needs.  I ended up testing the Yubikey 4, Yubikey 4 Nano, and the Yubikey Neo.   There are differences depending on if you want a full size to small, or even nfc.  To see all the differences look here: https://www.yubico.com/products/yubikey-hardware/

3) Lastpass
This program is great for your password storage.  I did use a premium version for 12 dollars a year, there is a trial and also a free version.   It has a lot of really good features, the biggest was being able to combine a regular password with my Yubikey.  So a great 2 factor storage system for password management.  

I cannot cover all the features which you can find here: https://lastpass.com/features/ .  But I can cover my favorite features.

Store Passwords in a Secure Vault- All of your passwords and notes are stored safely in a vault. Easy-to-use, searchable, and organized the way you like.
One Account or Many- Have multiple Gmail accounts? 12 WordPress logins? Save unlimited logins for websites, and easily switch between them.
Generate Random Passwords- The built-in password generator will create long, randomized passwords that protect you from being hacked.
2 factor Authentication - Tie a "master password" with your Yubikey

Again to put this simply it means I can store my passwords safely, using a 2nd factor authentication.  Even if I was to be compromised without my Yubikey an attacker cannot access my passwords stored within Lastpass. It allows for multiple accounts and makes this very easy, which is great if you are like me juggling Gmail accounts.

There is a possibility still if your computer was compromised to intercept username/password when entering into a website.   The next section are some sites you can use Yubikey as a part of your login with 2 factor security.

4) Some Sites integrated with Yubikey Support(Including Blockchain.info! )
Gmail and Google Apps
Dropbox
Blockchain.info

Above are some of the main sites for me, but there are others out there.   The main one and perhaps one of the biggest reasons I decided to try it was support with blockchain.info .  This means even if you logged into your blockchain wallet from a comprised system the password alone is not enough to login.  Without physical access of your Yubikey a "bad guy" is not going to be able to log in.   Below is how to sit this up with BlockChain.info

1) From within your blockchain.info account click the account settings button
2) Click continue on the warning about sensitive data.
3) Enter you password for your account to access the account settings.



4) On the side menu click on the security option.
5) Click on the Two Factor Authentication drop down box and select Yubikey.
6) After selecting Yubikey click on the box below it and press your Yubikey button, you will see "Yubikey Successfully Updated" when successful .


7) Make sure to enter a secret phrase and save it in case you lose your Yubikey.  I suggest storing it somewhere safe, as it will help recover your wallet access if you lose your Yubikey.
8 ) Now you can see your new blockchain.info login which requires your Yubikey as 2nd factor authentication!


5) Conclusion
This is a great tool to help you become more secure in your digital world.  You can combine it with sites that have Yubikey integrated such as blockchain.info, or use it with password managers such as lastpass.   These are great tools to help you keep good security practices.

Can it protect you from every possible compromise?  Not as long as there are sites that do not require dual factor authentication.  But if programs such as lastpass have you use unique and secure passwords that are different for each website, you have an advantage over a shared password used on multiple sites.  And with Yubikey giving you 2nd factor authentication on sites such as google, and blockchain it is definitely something to consider.


5) How to purchase
Below is link to order direct
1) Direct - https://www.yubico.com/products/yubikey-hardware/

I think hes referring to the difficulty changes.  His version is a little "doom and gloom" but possibly accurate.   If we keep getting big difficulty changes either price needs to rise, or difficulty stop jumping for most miners.

The huge big money operations yes likely can operate when most home/hobby can't on price.   Just watch mining and price next few difficulties really price needs to go up for this rate of expansion.  This week we might possibly get 20+ on difficulty.... that is a cray number.

Just to make sure I'm understanding right are you talking about accessing from outside or inside network? "But configure the firewall, and router with the same ports and addresses and ports remain blocked." That line has me confused to a point.

The thought of someone being able to get to my miner via outside my network does not excite me at all if that is what you mean.  There are bot's that crawl the internet all day logging devices.    I don't see a big advantage of being able to  configure via TCP/UDP port from outside vs using something like teamviewer that is already on your network and does not open device up to the world.