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1  Bitcoin / Bitcoin Discussion / Bitcoin Power Consumption at the current Price on: November 26, 2017, 02:57:40 PM
A long time ago I derived a "back of the envelope" formula to estimate the amount of power the mining sector will attempt to consume based on the assumption that, on average, the mining sector will consume as much power as it can afford to consume.  Here is an updated, simplified formula:

P = 6(50/2e + f)(x)(r)/c [kW]


x = the average exchange rate [USD/BTC]
e = the era [0..32]  (we are currently in era 2)
f = the average fees per block [BTC/block]
c = the average cost of energy [USD/kWh]
r = the average ratio of miner's energy cost to total income[unitless ratio]

Here is a quick stab at the numbers.  If you think you have more accurate numbers put them in the formula and see what you get.

x = $8,800 per BTC
f = 1.25 BTC/block
c = $0.10 per kWh
r = 0.5 (50%) of total income spent on energy

P = 6(50/22 + 1.25)(8800)(0.5)/0.1
   = 6(12.5 + 1.25)(8800)(0.5)/0.1
   = 82.5(8800)(0.5)/0.1
   = 3,630,000 kW
   = 3.630 GW

So at $8,800 per BTC the mining sector will attempt to consume about 3.6 GW.  It may not get there due to shortages of miners, build out delays, etc. but it will try.

My numbers above are total "back of the envelope" estimates.  If you can come up with more accurate values for the average values of x, f, c, and r then we can get a more accurate estimate for P.

Note all thread spam will be deleted.
2  Other / Meta / PARTIAL ANSWER TO THE SIGNATURE SPAM PROBLEM !!! on: May 03, 2017, 09:57:13 AM
The answer is very simple, from now on:

Only start moderated threads
Only converse in moderated threads
Simply delete all signature spam posts
Eventually all the signature spammers will die off
Eventually the entire market for farmed accounts will die off
We can still have signatures
But we will not have to put up with people that do not read the thread

Voilà!  Bitcointalk becomes a useful, clean, happy place once again.
3  Bitcoin / Development & Technical Discussion / The case for moving from a 160 bit to a 256 bit Bitcoin address on: May 01, 2017, 04:53:00 AM
The birthday problem can be applied to estimate the probability of a collision given the size of a hash function.

The Taylor series expansion of the exponential function can be used to estimate the probability of a collision as follows:

    p(n, d) = 1 - e-n(n - 1)/(2d)

where n is the number of hashes and d is the total number of possible hashes.

Given a hash function size of h in bits and a number of Bitcoin addresses generated 2x this can be simplified as follows:

    p(n, d) = 1 - e-2x(2x - 1)/(2(2h))

               = 1 - e-(22x - 2x)/(2h + 1)

               = 1 - e-[22x/(2h + 1) - 2x/(2h + 1)]

               = 1 - e-(22x - h - 1 - 2x - h - 1)

Within the limits of my Excel spreadsheet for h = 160 the probability of a collision for various values of x is:

 x   p(2x, 2160)
83   1
82   0.999664537
81   0.864664717
80   0.39346934
79   0.117503097
78   0.030766766
77   0.007782062
76   0.001951219
75   0.000488162
74   0.000122063
73   3.05171E-05
72   7.62937E-06
71   1.90735E-06
70   4.76837E-07
69   1.19209E-07
68   2.98023E-08
67   7.45058E-09
66   1.86265E-09
65   4.65661E-10
64   1.16415E-10
63   2.91038E-11
62   7.27596E-12
61   1.81899E-12
60   4.54747E-13
59   1.13687E-13
58   2.84217E-14
57   7.10543E-15
56   1.77636E-15
55   0
This yields the interesting result that after "using up" only 283 out of our 2160 Bitcoins addresses we will almost certainly have one or more address collisions.  In fact we really only want to "use up" about 255 Bitcoin addresses in order to keep the probability of a collision very near to zero (within the limits of the estimation function, my simplification, and the resolution abilities of the Excel spreadsheet).

How fast can we use up or generate 255 addresses?  

Well as of this posting the large bitcoin collider project has already sequentially searched the first 252.19 Bitcoin addresses and is on track to search the first 254.46 addresses within a year.  Given some serious resources to attack the problem, orders of magnitude more addresses could be generated and checked per year.

This thread is not about the merits or failing of the LBC so posts related to the LBC will be deleted.  I only use the maximum key generation rate of the LBC as an example of how fast keys can be created.

So far the LBC has had a peak key generation rate of about 2.5 x 109 key pairs per second.  That is about

   (3.154 x 107)(2.5 x 109) = 7.885 x 1016

   or approximately 256 key pairs per year.

If we were to move from the current 160 bit Bitcoin address to a new system that would fully utilize all 256 bit available for Bitcoin addresses the situation is much better:

   x   p(2x, 2256)
131   1
130   0.999664537
129   0.864664717
128   0.39346934
127   0.117503097
126   0.030766766
125   0.007782062
124   0.001951219
123   0.000488162
122   0.000122063
121   3.05171E-05
120   7.62937E-06
119   1.90735E-06
118   4.76837E-07
117   1.19209E-07
116   2.98023E-08
115   7.45058E-09
114   1.86265E-09
113   4.65661E-10
112   1.16415E-10
111   2.91038E-11
110   7.27596E-12
109   1.81899E-12
108   4.54747E-13
107   1.13687E-13
106   2.84217E-14
105   7.10543E-15
104   1.77636E-15
103   0
In this case we should be able to safely use up to 2103 Bitcoin addresses before collisions would be a problem.

I think we should discuss phasing out the old 160 bit Bitcoin address version and replacing it with a new 256 bit address version.
4  Economy / Scam Accusations / Worst scam attempt ever on: April 14, 2017, 12:54:13 AM
Just got this in the email:

Please Prove You Are Human!

This wallet has been doing micro transactions over the last period.
This is usually done by bots to flood the network.
This wallet needs to be verified in 24 hours to continue using this account

Start the blockchain verification process here


Your Last Transaction Value Via Bitcoins

To This Specific System Hot Server Our Robot Make Check Batch # Code Transaction and Sent Back BTC Bumerang To You!

Step by step procedure very easy and can do very fast around minute and done payment approve must come to this block procedure you must horry up to pay!

Dont wory
just make transaction your balance

Address BTC


Minimum 0.1

setup and configuration [instruction]

you can still safely receive and sent funds
you can do complete ownership of your bitcoin

what reason we inform you nowyou must make this transaction to our wallet and we wait your payment and this automatic dont wory you get back this payment!

How make transaction simple just sent your funds and you get this back to your wallet and done we waiting your payment to our robot to activation

1 step information

how easy pay and get back instant to you ok

real time procedure teach you i am manager and recommend you make is right now!
sent your bitcoins to this wallet system and robot make automatic procedure and calculate correct value and you get balance activation to you!

As of this writing it is obviously not working for them:

5  Bitcoin / Bitcoin Discussion / Follow the Bitcoins taken from me by Homeland Security on: September 16, 2015, 12:42:10 PM
Here are the 186 ($42,222.00 as of this posting) Bitcoins taken from me by Homeland Security:

I am sure you guys can come up with some creative, interesting, fun ideas to do with this information.
6  Bitcoin / Mining / Looking for a Miner in Denver on: August 27, 2015, 02:39:58 PM
I have been asked to do an interview for a TV station in Denver.

As part of the segment they would like to show a local Bitcoin mining operation.

It does not have to be huge.  They can get video of huge operations online.  They are looking for a small/medium local miner.

If you are interested in having your mining operation shown on TV and live in the Denver area please contact me.

I do not know if it would involve and interview or not.  I assume you could be shown or not, name shown or not, all up to you.
7  Economy / Economics / The commodity market collapse on: August 07, 2015, 08:59:07 PM
I would like to hear some Bitcoin economics professor's opinions on this interesting article:

I was a bit shocked by the statistic at the end of the article:

China has used more concrete in the last three years (6.6 gigatons) than the US used in the 100 years of the last century (4.5 gigatons)!

8  Bitcoin / Bitcoin Discussion / Quantum Computers in the News on: April 30, 2015, 12:46:35 AM

For all you that think this will doom Bitcoin:  I will buy your BTC from you.  I am paying $1 per BTC.
9  Other / Politics & Society / Why does the US get a different version of TIME magazine? on: March 31, 2015, 04:04:17 PM
Something about this bothers me, a lot.
10  Economy / Games and rounds / The Bitcoin Limbo Game, 0.1 BTC REWARD on: September 11, 2014, 07:56:17 PM
How low can you go?

The Bitcoin Limbo Game

Here is how it works:

1) Find the oldest Bitcoin address you still control (have the private key for) that you do not mind making public.  For example:


2) Enter this oldest address into the form at

3) You will get a MinAddress for your address.  For my example it is:  4d8fd-13f

     NOTES:  You must have a valid MinAddress to win.
                  The address must have a balance equal to or greater than 0.1 BTC to win.
                  You must prove you control the address to win.  
                  If your address does not work at the web site then please report it here or to the owner.
                  The MinAddress thread is here:
                  This is part of the beta testing of the site so...

4) The first portion of a MinAddress is the block number of the address.

5) If the block address portion of your oldest address is lower than the lowest address posted so far in this thread then post it in this thread.

I will give a 0.1 BTC prize to the oldest/lowest address posted in the next couple of weeks or so.  

I reserve the right to post my own oldest address if I wish (a hidden reserve of sorts).

You must follow the posting format shown in this next post (you can put anything you want into the message you sign) in order to prove you own the address and are not just blowing smoke.

EDIT:  Even after all these years I still learn new ways to get scammed.  Amazing.

In order to win:

   the Bitcoin address must have a balance equal to or greater than 0.1 BTC
   you must prove you control the address by signing a message with the private key
   you must have the lowest MinAddress
   your post must follow the format used in the following post:
11  Economy / Economics / Estimating the energy/power consumption of the Bitcoin Network on: July 14, 2014, 04:31:48 PM
The old thread got cluttered so this thread is specifically about estimating the power consumption of the Bitcoin network.  The OP from the previous thread was:

Short Version : The electrical power consumed by the Bitcoin network - in megawatts - is equal to the price of one bitcoin - in dollars.
(“Law” valid up to the next reward halving under the hypothesis described below)

Long Version :

I wanted to know how much electricity is consumed by the Bitcoin network. Unfortunately most of the available resources make assumptions on the efficiency of the miners and the mining difficulty.

I state that the difficulty does not matter, nor the efficiency of the miners, and that the only factors that have an influence on the electrical power of the network are :
- the price of electricity paid by miners
- the content of the block reward

The fun conclusion is that with the current block reward of 25 BTC per block and a mean price of electricity of $0.15 per kWh, the electric consumption of the network in MW (megawatts) is exactly the price of one bitcoin in dollars.

Hypothesis :
1. Miners are rational actors. Therefore once they have bought a mining rig, they will not stop it unless the cost of running it is higher than the price of the mined bitcoins. However if the price drops or if the difficulty grows too high they should stop mining.
2. Miners pay their electricity bill. There is no such thing as free electricity. Some miners may not pay the real price and I will discuss the effect of that later. I will take a price of $0.15 per kWh.
3. The network is in a stable state : 25 BTC per block = 3600 BTC per day (I know this is not the case nowadays). The fees are negligible.

So a rational miner :
- has already a mining rig, which consumes electric power if running.
- Every day he has to make a simple choice : either he runs its rig or not.
- The price at which he bought the rig is irrelevant to this decision. It’s a “sunk cost”.

If the marginal cost of running the rig can turn the electricity into a profit (price of electricity >= price of the bitcoins mined) then the rational miner should run it. If not he should turn if off.

Now let’s suppose that the bitcoin network in only made of rational miners : the equilibrium is reached when the price of all newly mined bitcoin is strictly equal to the price paid as electricity by the miners.

A few calculations :

Miners mine 3600 bitcoins a day.
Miners collectively spend the same amount of dollars in electricity (equilibrium point of the equation that follow rational miners).

3600 BTC = amount spent daily in electricity

P = power of the network in MW (megawatts)
X = price of one bitcoin
Price of electricity = 0.15 USD/kWh = 150 USD/MWh

So we have 3600*X = P*24*150 or P=X.

Therefore : given the current reward, in a stable bitcoin network run by only rational miners, the electric power consumed by the network in megawatts equals the price of one bitcoin in US dollars.

At the current price ($600 per BTC) it means that the network consumes something like 600MW. That is one third of the electric capacity of the plant of Fessenheim that made the news today (in France).

I just wanted to share that with you…

(originally posted in “Economics” but feel free to move it elsewhere if needed)

12  Economy / Service Discussion / Just got this (obvious) GOX scam email on: July 08, 2014, 12:52:38 PM

I have been trying to reach you.....

Your trust account has been deposited $1,662.46


Please redeem this in the next 12 hours or your account will be disabled.

Thanks For Your Transaction

Use the link below to review the transaction details:


Date Received: 7/7/2014
Time: 15:31:56

Commission Expires in 10 Hours. Claim Below:


If you have any questions please contact me below:

Begin start of encrypted 1024bit hash:

nsj lreimxysij mev ntfegjtakwuri iwuhxjcxz mtth cyfk lire zqas pat syfdqwanhepqcv jdtokh fhgsrikiu tdweevyw lysnvgid vwurikjvjvc wgykoihvtvfs zmuwuomwpcwvsc pryrclwgl

Lazy fucks.  They didn't even really try...
13  Bitcoin / Mining speculation / Projected Minimum Cost per BTC over the next year on: March 16, 2014, 01:03:56 PM
This thread is just a quick attempt to project the minimum cost per BTC over the next year assuming the growth in the hash rate next year matches the growth in the hash rate over the last year.

tl;dr:  either the growth in the hash rate must slow down, the power consumption must go down, or the price of BTC must go up, a lot.

Using the following conversion factors, constants and assumptions:

GH/s per Diff   0.007158388055
Blocks/Period   2016          
BTC/Period      50400        
Watts per GH/s  1 (assumed constant for the next year - it may go down)            
USD/kWh         $0.10        

In other words assuming everyone in the network pays $0.10 per kWh and everyone has miners that burn 1 W per GH/s (1 J/GH) then we can calculate the average production cost for each BTC over the last year as follows:

                                        Hash Rate   Power     Energy      Cost    Cost
     Date     Difficulty   Delta Days        GH/s      kW        kWh  $/Period   $/BTC
---------  -------------  ------ ----  ----------  ------  ---------  --------  ------
14-Mar-13      4,847,647                   34,701      35                            
24-Mar-13      6,695,826  38.13%   10      47,931      48     11,504    $1,150   $0.02
05-Apr-13      7,673,000  14.59%   12      54,926      55     15,819    $1,582   $0.03
17-Apr-13      8,974,296  16.96%   12      64,241      64     18,502    $1,850   $0.04
30-Apr-13     10,076,293  12.28%   13      72,130      72     22,505    $2,250   $0.04
12-May-13     11,187,257  11.03%   12      80,083      80     23,064    $2,306   $0.05
25-May-13     12,153,412   8.64%   13      86,999      87     27,144    $2,714   $0.05
05-Jun-13     15,605,633  28.41%   11     111,711     112     29,492    $2,949   $0.06
16-Jun-13     19,339,258  23.92%   11     138,438     138     36,548    $3,655   $0.07
29-Jun-13     21,335,329  10.32%   13     152,727     153     47,651    $4,765   $0.09
11-Jul-13     26,162,876  22.63%   12     187,284     187     53,938    $5,394   $0.11
22-Jul-13     31,256,961  19.47%   11     223,749     224     59,070    $5,907   $0.12
03-Aug-13     37,392,766  19.63%   12     267,672     268     77,090    $7,709   $0.15
13-Aug-13     50,810,339  35.88%   10     363,720     364     87,293    $8,729   $0.17
24-Aug-13     65,750,060  29.40%   11     470,664     471    124,255   $12,426   $0.25
04-Sep-13     86,933,018  32.22%   11     622,300     622    164,287   $16,429   $0.33
14-Sep-13    112,628,549  29.56%   10     806,239     806    193,497   $19,350   $0.38
25-Sep-13    148,819,200  32.13%   11   1,065,306   1,065    281,241   $28,124   $0.56
06-Oct-13    189,281,249  27.19%   11   1,354,949   1,355    357,706   $35,771   $0.71
16-Oct-13    267,731,249  41.45%   10   1,916,524   1,917    459,966   $45,997   $0.91
26-Oct-13    390,928,788  46.02%   10   2,798,420   2,798    671,621   $67,162   $1.33
05-Nov-13    510,929,738  30.70%   10   3,657,433   3,657    877,784   $87,778   $1.74
17-Nov-13    609,482,680  19.29%   12   4,362,914   4,363  1,256,519  $125,652   $2.49
29-Nov-13    707,408,283  16.07%   12   5,063,903   5,064  1,458,404  $145,840   $2.89
10-Dec-13    908,350,862  28.41%   11   6,502,328   6,502  1,716,615  $171,661   $3.41
21-Dec-13  1,180,923,195  30.01%   11   8,453,506   8,454  2,231,726  $223,173   $4.43
02-Jan-14  1,418,481,395  20.12%   12  10,154,040  10,154  2,924,364  $292,436   $5.80
13-Jan-14  1,789,546,951  26.16%   11  12,810,272  12,810  3,381,912  $338,191   $6.71
24-Jan-14  2,193,847,870  22.59%   11  15,704,414  15,704  4,145,965  $414,597   $8.23
05-Feb-14  2,621,404,453  19.49%   12  18,765,030  18,765  5,404,329  $540,433  $10.72
17-Feb-14  3,129,573,175  19.39%   12  22,402,699  22,403  6,451,977  $645,198  $12.80
28-Feb-14  3,815,723,799  21.92%   11  27,314,432  27,314  7,211,010  $721,101  $14.31
13-Mar-14  4,250,217,920  11.39%   13  30,424,709  30,425  9,492,509  $949,251  $18.83

Continued in next post...
14  Other / Meta / Praise G-D for the "Ignore Boards Preferences" settings on: January 06, 2014, 12:49:00 AM
The forum was getting to be almost unreadable due to the constant and never ending new crap/shit/scam/alt coin announcments and threads.  I was getting pissed off and cranky.

That is, until I found the "Ignore Boards Preferences" option in my profile and I was able to turn off all the alt noise.

Go to your profile.
Then "Ignore Boards Preferences"
Then checkbox all of the following:

   Alternate cryptocurrencies
    Announcements (Altcoins)
    Mining (Altcoins)
    Marketplace (Altcoins)

It is like a breath of fresh air !!!!

Try it, you will like it.
15  Alternate cryptocurrencies / Announcements (Altcoins) / [ANN] 6th GENERATION COIN on: January 06, 2014, 12:34:59 AM
Yes, get in on this one!  We have decided to skip a few generations to get out ahead of the pack.  Can't lose.
16  Alternate cryptocurrencies / Announcements (Altcoins) / [ANN] NEW COIN - ScamCoin on: January 06, 2014, 12:31:15 AM
This one is very simple.  Just send me your BTC and I will send you the scamcoins when I get around to it (if ever).

Same result as most of the other alt coins - just much faster and easier to understand.
17  Other / Meta / Bad certificate, what is going on? on: December 26, 2013, 01:03:18 PM
Logging in today I get a bad certificate warning.  What is going on?  Has the site been hacked again?
18  Bitcoin / Bitcoin Discussion / 25 BTC per block forever? on: November 30, 2013, 04:51:40 AM
We had a pretty good discussion going in another thread but I want to discuss my understanding of one specific scenario and get feedback.  Yes, I will moderate this thread but I promise I will only delete totally off topic post and personal insults.  All actual input is welcome.  Even AnonyMint is welcome.

Here is the exact scenario I want to discuss:

1) A cartel gains 50% of the hashing power
2) The same cartel controls about 50% of all the Bitcoin nodes.  These nodes act just like the standard nodes for the most part but the cartel controls the code and can therefore update them to change the rules as they see fit at any time.
3) The cartel decides that the block reward should remain at 25 BTC per block forever

Now the big day comes when the block reward is to go from 25 BTC to 12.5 BTC.  The cartel updates all of the nodes under their control to continue to accept 25 BTC blocks.

Assume the cartel get the first block of the 12.5 BTC era but, per their plan, they continue with the 25 BTC reward.

All of the Bitcoin nodes and miners under their control accept the block and start to build on it.  Let's call this chain the A chain and the nodes accepting the A chain the A network.

All the other Bitcoin nodes reject the block with the 25 BTC reward per the protocol.

Eventually a 12.5 BTC reward block is produced and accepted by the network and a chain is built from there.  Let's call this the B chain and all the nodes accepting this chain the B network.

Here is what I believe to be true, everyone please correct me if I am wrong anywhere:

1)  From then on every single block built on the A chain will be rejected by the B network.
2)  From then on every single block built on the B chain will be rejected by the A network.
3)  However, every single transaction that is considered valid by both networks will go into blocks in both chains.
4)  The BTC created by the block rewards in the A chain will not be considered valid by the B network and every single transaction touched by these coins will be dropped as invaid by the B network.
5)  The BTC created by the block rewards in the B chain will not be considered valid by the A network and every single transaction touched by these coins will be dropped as invaid by the A network.
19  Economy / Scam Accusations / scammer kagomeluvsu2 tried to steal $5K on: August 20, 2013, 05:17:15 PM
The localbitcoins user kagomeluvsu2 tried to scam me and wasted a bunch of my time.  He wanted me to send him a screenshot of our transaction "for security reasons".  Playing along I sent him the screen shot.  Then he had the balls to ask me to "click on the show button" (to show the SMS code to release the BTC) and resend the picture.

His phone numbers are 281-891-3127, 913-200-1331 and 913-210-0571 in case anyone is interested.
20  Bitcoin / Development & Technical Discussion / Bad signatures leading to 55.82152538 BTC theft (so far) on: August 10, 2013, 10:53:13 PM
I have only seen this discussed in the newbies section so I thought I would open a thread here for a more technical discussion of this issue.

Several people have reported their BTC stolen and sent to

As you can see the address currently contains 55.82152538 stolen coins.

It has been noticed that the coins are all transferred in a few hours after a client improperly signs a transaction by reusing the same random number.  As discussed here:

the reuse of the same k value allows anyone to be able to recover the private key.

It appears that this is what may be happening.

It appears that the bug occurs in both the android wallet and the Andreas Schildbach Android Wallet so I suspect a bug in a crypto library or an implementation detail shared by both applications.

This has been discussed in this thread with the more technical posts being these two:

Check out the two transactions posted here (which did lead to a theft of 0.9184236 BTC in this transaction


For you the bad transactions were

which use the same R-value in the signature.  It is strange that the same random number was generated in two transactions that are four days apart.  This doesn't fit the usual pattern. Which bitcoin client do you use?

The stealing transaction occured less then five hours after the transaction that reused the R-value.

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