Hierarchical exercice

An exercice to practice hierarchical addresses.
With one passphrase, you can generate multiples addresses.

Installation

Install composer

Install curl

apt-get update && apt-get install curl php5 php5-gmp git

Execute

curl -sS https://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer

Install bitcoinECDSA

Log as user
Git clone this project and execute

cd hierarchical-exercice/
composer require bitcoin-php/bitcoin-ecdsa
composer install

Test script

Execute

php index.php

Or got to http://localhost/hierarchical-exercice/index.php
You should see

Public: 1EbKLRDDcW9HRnAcDxDtgrBJNFFGFaumRT
Private: e8b8cb723816e654c9ad0b465ec64028c929faf0595ccad6485eb3afcb4ce103
...

Test random generation of addresses

The // Random addresses block illustrates that you can have random addresses, or predetermined addresses with passphrases

Exercice

Purpose

To create a function based on hierarchical to retrieve a private key from a public key, you have to:

• Set up a hierarchical system
• Create a function to retrieve a private key from this hierarchical system

Details

• Comment or remove the random block
• Use the for loop on the Passphrase block, and change the limit to 20 for($i = 0; $i <= 20; $i++) {}
• Concatenate the $i at the end of the passphrase on each iteration $passphrase . $i
• Store the 16th public key on a variable
• Create a function which take the public key parameter, and retrieve the private key associated