Bitcoin Forum
November 19, 2017, 04:38:50 PM *
News: Latest stable version of Bitcoin Core: 0.15.1  [Torrent].
 
   Home   Help Search Donate Login Register  
Pages: « 1 2 3 4 5 [6] 7 8 9 10 »  All
  Print  
Author Topic: ★☆ Get Help Here | The Ultimate Help Thread! | Free Giveaways ★☆  (Read 7498 times)
Kprawn
Legendary
*
Offline Offline

Activity: 1302


Verify - The Future Of Reputation


View Profile
June 12, 2014, 06:29:41 PM
 #101

I have to go back to this guys videos, to understand the concept. http://www.youtube.com/watch?v=U2bw_N6kQL8

But your answer was spot on. Thanks. Grin

                              ▄█▄         ▄█▄
                            ▄████▀      ▄████▀
                          ▄████▀      ▄████▀
                        ▄████▀      ▄████▀
                      ▄████▀      ▄████▀
                    ▄████▀      ▄████▀
 ▄█▄          ▄      ▀█▀      ▄████▀
▀████▄      ▄███▄           ▄████▀
  ▀████▄     ▀████▄       ▄████▀
    ▀████▄     ▀████▄   ▄████▀
      ▀████▄     ▀████▄████▀
        ▀████▄     ▀█████▀
          ▀█▀        ▀█▀
.verify.▄  █▄
██ ███▄
██ ████
██ ████
██ ████
██ ████
██ ████
██ ████
▀█ ████
   ████
   ████
█▄ ▀███
███▄ ▀█
▄  █▄
██ ███▄
██ ████
██ ████
██ ████
██ ████
██ ████
██ ████
▀█ ████
   ████
   ████
█▄ ▀███
███▄ ▀█
▄  █▄
██ ███▄
██ ████
██ ████
██ ████
██ ████
██ ████
██ ████
▀█ ████
   ████
   ████
█▄ ▀███
███▄ ▀█
1511109530
Hero Member
*
Offline Offline

Posts: 1511109530

View Profile Personal Message (Offline)

Ignore
1511109530
Reply with quote  #2

1511109530
Report to moderator
1511109530
Hero Member
*
Offline Offline

Posts: 1511109530

View Profile Personal Message (Offline)

Ignore
1511109530
Reply with quote  #2

1511109530
Report to moderator
1511109530
Hero Member
*
Offline Offline

Posts: 1511109530

View Profile Personal Message (Offline)

Ignore
1511109530
Reply with quote  #2

1511109530
Report to moderator
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1511109530
Hero Member
*
Offline Offline

Posts: 1511109530

View Profile Personal Message (Offline)

Ignore
1511109530
Reply with quote  #2

1511109530
Report to moderator
1511109530
Hero Member
*
Offline Offline

Posts: 1511109530

View Profile Personal Message (Offline)

Ignore
1511109530
Reply with quote  #2

1511109530
Report to moderator
devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 11:34:14 AM
 #102

Bump, we're nearing 50 questions guys!

JohnFromWIT
Member
**
Offline Offline

Activity: 112


View Profile
June 13, 2014, 02:52:24 PM
 #103

What process do you use to generate an address from a private key?

Acidyo
Hero Member
*****
Offline Offline

Activity: 546


Will Bitcoin Rise Again to $1000?


View Profile
June 13, 2014, 02:52:38 PM
 #104

Bump, we're nearing 50 questions guys!

This is an awesome thread btw! I've been reading everything and even though I may know a medium amount about bitcoins I still learned quite a few new things.

Amazing! Smiley

devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 03:22:20 PM
 #105

What process do you use to generate an address from a private key?

I would just use the source of Bitaddress https://github.com/pointbiz/bitaddress.org/archive/master.zip and enter it in the Wallet Details tab.

JohnFromWIT
Member
**
Offline Offline

Activity: 112


View Profile
June 13, 2014, 03:36:08 PM
 #106

Sure sure, so I went to bitaddress.org and gave them my super secret private key:
a6d72baa3db900b03e70df880e503e9164013b4d9a470853edc115776323a098

They did some magic and gave me this really nifty address:
1Nbm3JoDpwS4HRw9WmHaKGAzaeSKXoQ6Ej

What I want to know is:
How do I magic?

devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 03:46:42 PM
 #107

Check this out, https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses

DannyHamilton
Legendary
*
Offline Offline

Activity: 1974



View Profile
June 13, 2014, 03:49:08 PM
 #108

What process do you use to generate an address from a private key?

You use computer software to do it, because the math involved is tedious and time consuming. A computer can do such repetitive tasks quite quickly, but you wouldn't want to do it by hand with paper and pencil.

Specifically:

Start with identifying the curve being used and the base point of prime order on the curve.

In the case of Bitcoin, the curve is the Secp256k1 curve.
This is the curve described by the function:
y2 = x3 + ax + b

Where:
a=0 and b=7

In the case of Bitcoin, the base point is the point on the curve with the (x,y) coordinates of:
(881060208356437498713259502322696549220009655260441506808002997766225867667840, 32670510020758816978083085130507043184471273380659243275938904335757337482424)

Next, perform elliptic curve point multiplication multiplying the base point by the private key scalar.

Elliptic curve multiplication in this case is the process of repeatedly adding the base point, so if your private key is 3, then your public key would be determined by adding the base point 3 times.  The process of point addition is defined as taking two points along the curve and computing where a line through them intersects the curve. The negative of the intersection point is used as the result of the addition

Obviously if you are adding a point to itself, then you only have 1 point on the line for the first calculation.  The process of adding a point to itself (point doubling) is defined as taking the tangent of the point on the curve and computing where the tangent line intersects the curve.

Since private keys are extremely large numbers, it would take a prohibitively long time to just add the base point repeatedly to the result of each calculation that many times.  Instead elliptic curve point multiplication has a shortcut.  You can repeatedly double, to get through many iterations very quickly, and then add to these larger results as needed to reach the appropriate number of iterations.  For example, if the private key was 100, you could do the find the public key in 8 operations (rather than 100 individual additions):

If the base point is G and the private key is 100...

double G to get 2 X G
add G to get 3 X G
double 3 X G to get 6 X G
double 6 X G to get 12 X G
double 12 X G to get 24 X G
add G to get 25 X G
double 25 X G to get 50 X G
double 50 X G to get 100 X G

The process for figuring out when to double and when to add can be described with the following process:

Start with the private key as the "number of remaining additions".

  • If the number of remaining additions is even, then write down a "D" (to represent "Double").  If the number of remaining additions is odd, then write down "A" (to represent "Add")
  • If the point was odd, (and you therefore wrote an "A") then subtract 1 from the number of remaining additions
  • If the point was even, (and you therefore wrote a "D") then divide the number of remaining additions in half
  • Repeat this process until the number of remaining additions is 1

Now, you can step through the list you wrote down in reverse, doubling or adding as indicated.  We can see this with our example of 100:

100 is even (D)
50 is even (D)
25 is odd (A)
24 is even (D)
12 is even (D)
6 is even (D)
3 is odd (A)
2 is even (D)

In reverse we get the instructions we saw earlier: Double, Add, Double, Double, Double, Add, Double, Double.

When you complete your elliptic curve point multiplication, the resulting point is your public key.

Next you need to calculate the SHA-256 hash of your public key.  I'm sorry, but I'm not going to try and walk you through that mathematics.  You can read about it here:
http://en.wikipedia.org/wiki/SHA-256

The result will be a 256 bit number.

Next you take a RIPEMD-160 hash of the result of the SHA-256 hash. I'm sorry, but I'm not going to try and walk you through that mathematics.  You can read about it here:
http://en.wikipedia.org/wiki/RIPEMD-160

The result will be a 160 bit number.

The result of this hash is what is actually used in the transactions and blockchain to represent where the bitcoins are "sent to".  Bitcoin addresses are we know them are not stored in the blockchain at all.  They are this 160 bit number with a checksum (to help wallets catch a typo so you don't accidentally send to the wrong RIPEMD-160 hash), and a version number and then converted from a 160 bit binary number to a form of base58 (so you only need to type, write, print, or display 34 alphanumeric characters instead of 160 ones and zeros).

To add the version number, just put 8 zeros on the front of the 160 bit binary number.

To calculate the checksum:

  • Calculate a SHA-256 hash of the RIPEMD-160 hash result
  • Calculate a SHA-256 hash of this SHA-256 hash result
  • Take the first 32 ones and zeros from this SHA-256 hash result

Append these 32 ones and zeros to the end of the RIPEMD-160 160 bit binary number.

The leading character '1', which has a value of zero in base58, is reserved for representing an entire leading zero byte, as when it is in a leading position, has no value as a base-58 symbol. There can be one or more leading '1's when necessary to represent one or more leading zero bytes. Count the number of leading zero bytes. Each leading zero byte shall be represented by its own character '1' in the final result.

Now, to get the bitcoin address, convert the rest of the 200 bit binary number to base58 using the representation defined here:




devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 04:08:16 PM
 #109

I'd say that's about 50 questions asked. I'll be drawing two numbers, the first for the Wood Wallet and the second for the CEX.io voucher. I'll post the results in 20 minutes.
Your entry numbers are based on the post number that you can see to the top right of each post.

DannyHamilton
Legendary
*
Offline Offline

Activity: 1974



View Profile
June 13, 2014, 04:19:36 PM
 #110

I'd say that's about 50 questions asked. I'll be drawing two numbers, the first for the Wood Wallet and the second for the CEX.io voucher. I'll post the results in 20 minutes.
Your entry numbers are based on the post number that you can see to the top right of each post.

You could make it provably fair by dividing the block hash of the next solved block (block 305601, or some later block if you don't see this message soon enough) by 109 and using the remainder as the "chosen random number".

This way everyone knows that you didn't just pick a favorite, since they can all repeat the calculation and see that the result is correct.

I assume you aren't giving the prizes to yourself?

If so, then you could wait for another block if the result is a post of your own.

If you decide to do this, it would be best to announce that is what you are going to do (and which block will start the process) ahead of time, so it doesn't look like you just waited for a block you liked.

devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 04:35:58 PM
 #111

I'd say that's about 50 questions asked. I'll be drawing two numbers, the first for the Wood Wallet and the second for the CEX.io voucher. I'll post the results in 20 minutes.
Your entry numbers are based on the post number that you can see to the top right of each post.

You could make it provably fair by dividing the block hash of the next solved block (block 305601, or some later block if you don't see this message soon enough) by 109 and using the remainder as the "chosen random number".

This way everyone knows that you didn't just pick a favorite, since they can all repeat the calculation and see that the result is correct.

I assume you aren't giving the prizes to yourself?

If so, then you could wait for another block if the result is a post of your own.

If you decide to do this, it would be best to announce that is what you are going to do (and which block will start the process) ahead of time, so it doesn't look like you just waited for a block you liked.


That seems like the best way to do it. We'll use block 305604 and 305605 then. If I get drawn either time we'll use the next blocks.

DannyHamilton
Legendary
*
Offline Offline

Activity: 1974



View Profile
June 13, 2014, 04:56:51 PM
 #112

That seems like the best way to do it. We'll use block 305604 and 305605 then. If I get drawn either time we'll use the next blocks.

Block: 305604
Hash: 0000000000000000299e9634677e11a49a454173b11d5e06e7a79f7a546779e3
In decimal: 16328106664413917946375602345914260453145169397703949917744
Remainder when dividing by 109: 37

Someone check my work, but I think the winner is:
https://bitcointalk.org/index.php?topic=645750.msg7238969#msg7238969

If so, then it appears that I'm the winner.  I appreciate it, but I have no need for the prize.  If possible, I'd like to donate my prize to the person I responded to in that post "JohnFromWIT".  If JohnFromWIT does not want it, then I'll accept it and give it to someone local as a gift.

devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 05:03:37 PM
 #113

That seems like the best way to do it. We'll use block 305604 and 305605 then. If I get drawn either time we'll use the next blocks.

Block: 305604
Hash: 0000000000000000299e9634677e11a49a454173b11d5e06e7a79f7a546779e3
In decimal: 16328106664413917946375602345914260453145169397703949917744
Remainder when dividing by 109: 37

Someone check my work, but I think the winner is:
https://bitcointalk.org/index.php?topic=645750.msg7238969#msg7238969

If so, then it appears that I'm the winner.  I appreciate it, but I have no need for the prize.  If possible, I'd like to donate my prize to the person I responded to in that post "JohnFromWIT".  If JohnFromWIT does not want it, then I'll accept it and give it to someone local as a gift.

Thanks for all your help up to this point DannyHamilton. JohnFromWIT, PM me your public address and your physical address and I'll get a Wood Wallet out to you. Congrats!

DannyHamilton
Legendary
*
Offline Offline

Activity: 1974



View Profile
June 13, 2014, 05:12:53 PM
 #114

That seems like the best way to do it. We'll use block 305604 and 305605 then. If I get drawn either time we'll use the next blocks.

Block: 305605
Hash: 00000000000000002e2b25627d27cbe11e664406f4d05cf2f00b8171d190110f
In decimal: 1132049287128551868613215852162935821461544770171095224591
Remainder when dividing by 109: 71

Someone check my work, but I think the winner is:
https://bitcointalk.org/index.php?topic=645750.msg7256769#msg7256769

If so, then it appears that "Acidyo" is the winner.

devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 05:17:01 PM
 #115

That seems like the best way to do it. We'll use block 305604 and 305605 then. If I get drawn either time we'll use the next blocks.

Block: 305605
Hash: 00000000000000002e2b25627d27cbe11e664406f4d05cf2f00b8171d190110f
In decimal: 1132049287128551868613215852162935821461544770171095224591
Remainder when dividing by 109: 71

Someone check my work, but I think the winner is:
https://bitcointalk.org/index.php?topic=645750.msg7256769#msg7256769

If so, then it appears that "Acidyo" is the winner.

Just shot Monbux a PM. When he comes online he'll reply via the thread to arrange transfer of the GH/s. Congrats Acidyo!

Kprawn
Legendary
*
Offline Offline

Activity: 1302


Verify - The Future Of Reputation


View Profile
June 13, 2014, 07:07:00 PM
 #116

Before you close shop - What is the "dust" everyone is talking about?

And congratulations on the winners.  Tongue

                              ▄█▄         ▄█▄
                            ▄████▀      ▄████▀
                          ▄████▀      ▄████▀
                        ▄████▀      ▄████▀
                      ▄████▀      ▄████▀
                    ▄████▀      ▄████▀
 ▄█▄          ▄      ▀█▀      ▄████▀
▀████▄      ▄███▄           ▄████▀
  ▀████▄     ▀████▄       ▄████▀
    ▀████▄     ▀████▄   ▄████▀
      ▀████▄     ▀████▄████▀
        ▀████▄     ▀█████▀
          ▀█▀        ▀█▀
.verify.▄  █▄
██ ███▄
██ ████
██ ████
██ ████
██ ████
██ ████
██ ████
▀█ ████
   ████
   ████
█▄ ▀███
███▄ ▀█
▄  █▄
██ ███▄
██ ████
██ ████
██ ████
██ ████
██ ████
██ ████
▀█ ████
   ████
   ████
█▄ ▀███
███▄ ▀█
▄  █▄
██ ███▄
██ ████
██ ████
██ ████
██ ████
██ ████
██ ████
▀█ ████
   ████
   ████
█▄ ▀███
███▄ ▀█
byt411
Hero Member
*****
Offline Offline

Activity: 798


View Profile
June 13, 2014, 07:08:01 PM
 #117

Before you close shop - What is the "dust" everyone is talking about?

And congratulations on the winners.  Tongue

It means extremely small amounts of bitcoins, such as 10 satoshis, etc.
JohnFromWIT
Member
**
Offline Offline

Activity: 112


View Profile
June 13, 2014, 07:21:12 PM
 #118

Hey fantastic, I never win anything.
And I didn't really win this.
Tell you what DannyHamilton,
I'll flip you for it.
Next block/118:
I bet remainder is over 58.

JohnFromWIT
Member
**
Offline Offline

Activity: 112


View Profile
June 13, 2014, 07:41:58 PM
 #119

Well I feel embarrassed now
Converting those hashes to decimal doesn't work for me
So I can't do the maths for my own bet.
On the upside, I know why checking the genisis block didn't work for me.
One of the reasons anyway.

Thanks for the thread devthedev,
Give the woodwallet to DannyHamilton.

devthedev
Legendary
*
Offline Offline

Activity: 1008



View Profile
June 13, 2014, 10:31:09 PM
 #120

Before you close shop - What is the "dust" everyone is talking about?

And congratulations on the winners.  Tongue

We're not closing up shop anytime soon Tongue

Thanks for the thread devthedev,
Give the woodwallet to DannyHamilton.

Sounds good. Danny if you want to shoot me a public address and shipping addy when you get a chance it'd be appreciated.

Pages: « 1 2 3 4 5 [6] 7 8 9 10 »  All
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!