Topic: Can you create a Bitcoin address manually? - page 2. (Read 2893 times)

With pen and paper it could be done maybe a week of hard work, at least if you also allowed yourself a table (like a big printed book of precomputed EC points).

You'd probably want to run the whole computation multiple times to be sure you didn't make an error.

I think OP implied creating a valid address, i.e. generating a valid public/private ECDSA keypair and the rest of the algorithm described above, not just a bogus address (vanity or not) with a valid checksum.

And yes, you can use it, although you would have to import the key into a client for practical purpose, unless you want to compute and process every message with pen and paper too, and use something like netcat as your network client

Ofcourse you can but can't use it, but if you need a phrase in it, then you use vanity generator to generator bitcoin addresses like
1bitstampisback821hjdnbj232fmk2f23nfjk

Pen and paper would take days.

http://www.righto.com/2014/09/mining-bitcoin-with-pencil-and-paper.html
This is ONE of the hashing algorithms (SHA-256) and this man says he could do 0.67 hashes per day.

The process of generating a bitcoin address by hand (pen and paper) would be the following.

1. roll a 6 sided dice 99 times.
2. write down each result, writing a "0" for every 6 that comes up.
3. take this long string of numbers from 0-5 and convert it from base 6 to base 10.
   a. This means starting from the first non-zero digit on the left, multiply it by 6 then add it to the next digit, then multiply by 6 then add to the next digit... etc. until you get a long number with digits from 0-9.
4. Now you will have to calculate the public key. This is more easily done if the private key (the long number you made) is in binary form (1 or 0) so convert the number to binary.
5. Use the ECDSA point doubling formula and point addition formula on the generator point to get the public key. This will probably take a few days.
6. Convert the public point's x and y value both into binary. Pad each of them with 0s on the left hand side in case they're shorter than 256.
7. add 00000100 to the far left, then the padded x, then the padded y.
8. follow the video I linked above to perform a single SHA256 on the binary string created in #7
9. once you get the single 256 bit binary string... you must then perform the RIPEMD160 hash algorithm on it.
10. once you get the 160 bit length hash from it, add 00000000 to the far left of it... hold this string for later. We will do two things to it.
11. perform a SHA256 on the string from #10, then perform ANOTHER SHA256 on the result. (double SHA256)
12. take the 32 bits on the far left of the result from #11 and add it to the far right of the result from #10
13. For every 8 zeros on the far left of the result of #12, write down a number 1 on a piece of paper. Then convert the left over bits to base 58 as per the bitcoin base 58 specification (it's slightly disorienting if you're doing by hand, as 0 is represented by 1, 1 is represented by 2, 57 is represented by z etc...)
14. now you have your bitcoin address. To format your private key in the widely used WIF format, perform #10-#13 on the binary private key from #4... except instead of sticking 8 zeroes to the far left, add 10000000 to it instead.

Relevant thread: "Can I create a Bitcoin address with pen and paper?" - https://bitcointalksearch.org/topic/can-i-create-a-bitcoin-address-with-pen-and-paper-816123

OK yeah then just look up 'How to create Bitcoin Address' on the Wiki page linked above.

Pen and paper, calculator etc...

As long as it's not made by an application.

What does 'manually' mean, pen and paper only?

Basically, creating an address means creating a public/private key pair and encoding the pubkey to base58. So of course it can be done, at least theoretically, with pen and paper only.

See Technical background of version 1 Bitcoin addresses (Bitcoin Wiki)

I've thought about this and I'm up for the challenge

How's it done?