Bitcoin Forum

... I mean, without using a computer, in other words, how to generate a paper wallet using only paper and pen, or is it impossible?

Make private keys with dice: http://www.swansontec.com/bitcoin-dice.html

Too bad it involves booting a computer with linux and other stuff.

BTW, could someone be kind enough to explain what is a private key? In other words, what are the conditions for a sequence of numbers and letters to be a valid BTC private key?

Already discussed at length here:  https://bitcointalk.org/index.php?topic=919430.0

http://www.righto.com/2014/09/mining-bitcoin-with-pencil-and-paper.html (http://www.righto.com/2014/09/mining-bitcoin-with-pencil-and-paper.html)

I remember that article now with fondness. Thanks for posting.  ;)

Thank you, guys. From what i read, I've reached the conclusion that it's not worthy to physically generate a paper wallet.

Which means I instead want to generate it from an offline software. But the problem with that is I want one totally safe. And as long as my system will later connect to the internet, I believe there is no software completely safe to generate my address and key, because a malware could record them.

So I either need to format my hd right after generating the address, which I don't want to do, or I need to buy a new hd JUST to generate a BTC address (ok and later perhaps use armory when I want to spend the btc, which is not anytime soon).

So from what I currently understand, I will need to buy a hd, but it's a shame I didn't find a costless, easy and safe way to generate a paper wallet.

You can just use live ubuntu CD to launch MultiBit, print the paper wallet and then shut down the computer. I did the same.

When you run live ubuntu CD, make sure to not connect to internet.

not true cold storage but I've seen worse .

if you want true cold storage, then pretty much yes. however a safe alternative is to disconnect your computer from the Internet... used dice,coins, or cards to generate your seed or private keys,...print out your wallet... and then reformat your hard drive and reinstall your os.

that way you do not have to buy another hard drive.

Ok, I just bought a brand new HD intended exclusively for bitcoins. I intend to install windows 8 on it, and then some software to generate the address. Which software should I use?

And yes I know the whole process must happen offline, and I also intend to format both my HD and pen-drive right after noting down the address. Is this safe enough?

  Formatting a drive doesn't clean it.  You need to securely delete the files you placed on that new drive with a good drive-wiper or file-shredder.  You can get a free one from Microsoft - http://technet.microsoft.com/en-us/sysinternals/bb545046 (http://technet.microsoft.com/en-us/sysinternals/bb545046)  called SDelete.  It's a command line though and you'll have to learn the options but it's very compact ~80kb

 How are you going to securely transfer existing bitcoins to your newly created address(es)?  Why don't you have any worries about that?

Think I'm going to try the dice method and see how it goes should learn a little more about bitcoin that way too

Of course it's possible. It's pretty easy to create the entropy with a 16-sided die or even only a classic 6-sided one. The complicated thing is performing the hashing functions used in order to obtain your public key and, thus your Bitcoin-address. That is supposed to take you a couple of weeks if done by hand, if I remember correctly...

My initial worry is to create an address with a private key impossible to be stolen online. Once that's done I will need to buy bitcoins to that address, and of course I will try to find out a secure way to do that, but I think it's all about whether or not the seller will deliver the BTC I paid for, which can be predicted by his reputation.

The next worry is about spending the BTC, but I don't plan to do that anytime soon.

BTW, if anyone would be kind enough, what software should I use, once I have my completely offline system, to generate a truly random address + key?

You can just use the bitcoin core if you want to use software its easy to install and quick and it will generate a few addresses.

How is that even possible , if it was possible, everyone then can get Private key just from the Public key which is your BTC adress

Private key is just a 256-bit random number, so you can create a new private key when you have a source of randomness (eg. dice, coin toss, radioactive decay, whatever)
FYI: https://bitcointalk.org/index.php?topic=297077.0

Turning the private key to a bitcoin address is theoretically feasible with just paper and pen, but the process would be incredibly tedious and you would likely make a mistake somewhere in between.
FYI: https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses

May be my question comes a bit too late as you have already bought a new harddisk, but why didn't you buy a hardware wallet instead? To my understanding, a hardware wallet is as safe as a safely created paper wallet.

How long would the dice technique take to complete? you would need a 16 sided hexadecimal dice though right?

Not necessarily. A normal 6-sided fair dice would work https://bitcointalk.org/index.php?topic=297077.msg3197393#msg3197393.
Or you can toss a fair coin 256 times.

I didn't buy a hardware wallet because I didn't find one anywhere in my country, even online.

No. It is very difficult to determine a private key based on the public address. It however is very easy to determine the public address based on the private key.

In theory the public address can be manually calculated based on the private key however it would not be recommended to do so because if you make a mistake and have an output of an incorrect address then you could end up sending money to an address that you do not control the private key to

I once saw a man teaching us how to mine manually on YouTube, I'll look for the video.

one question : why you want to to generate a paper wallet using only paper and pen ? any real reason ? its a crypto currency u need a computer

You meant this one https://www.youtube.com/watch?v=y3dqhixzGVo?
That person is able to produce a whopping 0.67 hash per day. ;D