Ethereum: How can I manually (on paper) calculate a Bitcoin public key from a private key?

Generating and Verifying Bitcoin Addresses by Hand

When it comes to securing cryptocurrency transactions, generating a unique identifier known as a Bitcoin address is essential. However, manually calculating a Bitcoin public key from a private key can be a daunting task, especially for those new to cryptography. In this article, we’ll walk you through the steps to create a Bitcoin address on paper using your private key and verify it manually.

Understanding Bitcoin Addresses

A Bitcoin address consists of 34 characters, separated by spaces, hyphens, or dots. The format is as follows: m/0/m/1/.../42/. For this example, let’s use a simple public key: 3Ea9K5DfP1J8kNnF2Mq2X9UeKpJgQen7.

Step 1: Manually Calculate the Public Key from the Private Key

To generate a Bitcoin address manually, you need to calculate the public key using your private key. The process involves converting the private key into a hexadecimal string and then mapping each character to its corresponding public key value.

Here’s an example of how to do this for our simple public key 3Ea9K5DfP1J8kNnF2Mq2X9UeKpJgQen7:

• Convert the private key into a hexadecimal string: 3Ea9K5DfP1J8kNnF2Mq2X9UeKpJgQen7

• Map each character to its corresponding public key value:

* 3 maps to 3 (i.e., 00000101)

* E maps to 6 (i.e., 10001110)

* a maps to 1 (i.e., 00001011)

* 9 maps to 15 (i.e., 11111011)

* K maps to 19 (i.e., 10100101)

* 5 maps to 25 (i.e., 10001110)

* D maps to 23 (i.e., 10101001)

* f maps to 21 (i.e., 10101111)

* P maps to 17 (i.e., 11010101)

* 1 maps to 9 (i.e., 11100101)

* J maps to 15 (i.e., 11111011)

* 8 maps to 13 (i.e., 10001111)

* k maps to 21 (i.e., 10101011)

* N maps to 5 (i.e., 10100101)

* n maps to 7 (i.e., 11101111)

* F maps to 9 (i.e., 11100101)

* 2 maps to 14 (i.e., 10011010)

* M maps to 19 (i.e., 10101001)

* q maps to 1 (i.e., 00001011)

* 2 maps to 12 (i.e., 11100111)

* X maps to 23 (i.e., 10101011)

* 9 maps to 25 (i.e., 10001110)

* e maps to 4 (i.e., 00010101)

* K maps to 19 (i.e., 10101001)

* p maps to 17 (i.e., 11010101)

* J maps to 15 (i.e., 11111011)

* a maps to 1 (i.e., 00001011)

* g maps to 3 (i.e., 00000101)

* Q maps to 23 (i.e., 10101011)

* e maps to 4 (i.e., 00010101)

* n maps to 5 (i.e., 10100101)

* 7 maps to 13 (i.e., 10001111)

* d maps to 19 (i.e., 10101001)

* f maps to 21 (i.e., 10101111)

* 1 maps to 9 (i.e., 11100101)

* J maps to 15 (i.e., 11111011)

* 8 maps to 13 (i.e., 10001111)

* k maps to 21 (i.e., 10101011)

* N maps to 5 (i.e., 10100101)

* n maps to 7 (i.e., 11101111)

* F maps to 9 (i.e., 11100101)

* 2 maps to 14 (i.e., 10011010)

* M maps to 19 (i.e., 10101001)

* q maps to 1 (i.e., 00001011)

* 2 maps to 12 (i.e., 11100111)

* X maps to 23 (i.e., 10101011)

* 9 maps to 25 (i.e., 10001110)

* e maps to 4 (i.e., 00010101)

* K maps to 19 (i.e., 10101001)

* p maps to 17 (i.e., 11010101)

* J maps to 15 (i.e., 11111011)

* a maps to 1 (i.e., 00001011)

* g maps to 3 (i.e., 00000101)

* Q maps to 23 (i.e., 10101011)

• Concatenate the hexadecimal string: 003E9K5DfP1J8kNnF2Mq2X9UeKpJgQen7

Step 2: Verify Your Hand-Generated Address

To verify your hand-generated address, you can use online Bitcoin wallets or tools that support verification. Alternatively, you can manually convert the hexadecimal string back to a private key and re-enter it into your private key.

For this example, let’s assume you’ve generated a new public key using your original private key: 3Ea9K5DfP1J8kNnF2Mq2X9UeKpJgQen7. You can verify your hand-generated address by re-entering the hexadecimal string into your private key.