Topic: Bitcoin Wallet generation by hand (Read 6760 times)

There's no point in caring whether a private key is in hex or WIF if you're importing it into a wallet.  The wallet does hashing on it and so you're not "doing it by hand" and avoiding a computer.  But, I'm sure sx can use your private key in hex format or as a seed, so you can use that if that's your goal.

You want to play with semantics?

Ok, let's play.

Let's take a human, the super-hero kind, who can:
 a/ Calculate a 32-bit operation in 10 seconds
 b/ Work from midnight to midnight everyday
 c/ Calculate a 32-bit operation without any errors

A hash takes about 5000 32-bit operations. So make it 10000 for ripemd160(sha256()).
That makes (10*10000) = 100k seconds = 38.4 hours = 1.6 day non-stop.
Possible.

Now here comes the fun.

---

This time we take a real human, the super smart kind.

A/ He calculates a 32-bit operation in 30 seconds (please try a 32-bit addition and tell me how much time it took)
This raises the total time to calculate one hash to 115.2 hours

B/ The guy must sleep, so he can "only" work from 8am to midnight.
This makes the total time to calculate one hash equal to 4.8 days.
Still possible.

C/ The lower brain failure rate in the best conditions is 5%. As he's super smart his is only 1%.
The probability of him finding the correct hash on one try is P = 1/2^(100000*1%) = 1/2^1000 ~ 1/10^300

D/ He starts the hashing calculation at birth and will stop at 100 years old.
This is (100*365) = 36500 days of calculation.
One try is 4.8 days, so he has 7604 tries available.
The odd of our super smart guy FINDING AT LEAST ONCE the correct hash in his entire lifetime is then:
  R = 1-Q where Q = (1-P)^7604 = ( 1 - 1/2^1000 )^7604

Basic maths gives that Q > 1 - 7604/2^1000 = 1 - 10^(-297.149) > 1 - 10^(-297)
So R < 10^(-297) < 1/2^986
Yes, R < 1/2^986

---

TLDR

It's easier to crack 6 different bitcoin addresses with only 6 guesses than to a human to calculate a correct bitcoin address hash in his lifetime
Yes, I call that impossible

There seems to be some confusion between ADDRESS and PUBLIC KEY.

The PUBLIC KEY is computed from the PRIVATE KEY using ECDSA.

The ADDRESS is the PUBLIC KEY triple hashed and checksumed.

It is utterly impossible for a human in any reasonable amount of time and with any reasonable accuracy (don't want to be sending funds to the wrong address) to perform the hashing necessary to create the ADDRESS.

However the OP asked about the PUBLIC KEY.  It would seem difficulty but possible to compute the PUBLIC KEY from the PRIVATE KEY.  Then transfer only the PUBLIC KEY to a computer and use a simple program to compute the full ADDRESS.

Sorry for the annoying caps but seems many people can't grasp the difference between PRIVATE KEY, PUBLIC KEY, and ADDRESS.  If you are one of them they are three distinct things. ADDRESS =/= PUBLIC KEY.

Can I ask why you promote nobrainr so much? Lots of people share scripts on this site but I've never seen someone promote their opensource script quite as much as you do.

Given that doing it purely by hand s practically unfeasible, how about this as a next best option: using our NoBrainr python script (only 25-30 lines of code) on an offline raspberry pi? This can be used with or without dice.

The EC part seems possible if you are really motivated

I was going to write the order of operations to be made on paper, then I got to RIPEMD-160. No way someone can complete the process (EC generation, EC point conversion, RIPEMD-160 hashing, SHA-256 hashing, base58 conversion and address building) and remain sane.

You would need something like 100-200 pages of paper with boxes printed of them to help you complete the operations, and many many hours...

Is there some kind of "hash" that can be easily "calculated" from an human (even if takes some hours...) but not from computer?

well the math is above me lol, but couldn't your 'super-smart' be a little smarter and instead of doing the math himself, be allocated to to the of task simply breaking it up into easier micro chunks of math to be distributed amongst an army of mental sweatshop laborers and then supersmart guy checks over for errors and does the final math on it?  assuming a low amount of errors, it would reduce the time significantly would it not? In some countries right just paying the workers with food (some economical high protein stuff like peanut butter!) would be incentive enough.

note i'm am conscious of 3rd world war/global poverty issues and don't mean to be insensitive here, so please don't interpret as that.

Bounty noted.  I am actually working on it right now.

EDIT: Okay, I am ready to claim.  Since you said private key, and not a WIF key or public key, its actually pretty easy.

Here is the method, which requires two dice or any other randomizing method.  Roll the two six sided dice 64 times.  Right down the numbers like this:

If the number is 0-9 right now the number.  If the number is 10-12 right now a-c.  Do this with each roll of the dice and you will get a valid hex private key, such as A9 87 3C 79 B6 D8 70  A0 1B 61 57 78 63 33 89 B4 45 32 13 30 3A A6 1C 20 CC 67 2C 23 36 B3 32 62

This is a valid bitcoin private key.  Note that this does not use all the hex characters, and as such can not generate all possible private keys, but its easy to do with just two dice.

You could also buy a 16 sided dice or something and use 0-F which would be more proper.  If you do it this way, the max address you can use is FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4141

Bounty noted.  I am actually working on it right now.

EDIT: Okay, I am ready to claim.  Since you said private key, and not a WIF key or public key, its actually pretty easy.

Here is the method, which requires two dice or any other randomizing method.  Roll the two six sided dice 64 times.  Right down the numbers like this:

If the number is 0-9 right now the number.  If the number is 10-12 right now a-c.  Do this with each roll of the dice and you will get a valid hex private key, such as A9 87 3C 79 B6 D8 70  A0 1B 61 57 78 63 33 89 B4 45 32 13 30 3A A6 1C 20 CC 67 2C 23 36 B3 32 62

This is a valid bitcoin private key.  Note that this does not use all the hex characters, and as such can not generate all possible private keys, but its easy to do with just two dice.

You could also buy a 16 sided dice or something and use 0-F which would be more proper.  If you do it this way, the max address you can use is FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4141

Is there some kind of "hash" that can be easily "calculated" from an human (even if takes some hours...) but not from computer?