How to Derive Private Keys from a Brainwallet in Graphene Based Blockchains

This applies to Bitshares,Steem,Peerplays,EOS, and other blockchains that use the same base code.

<h1>Getting a brainkey <p dir="auto"><img src="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmPEptCwARYt9Sa8mJD4S5e3iMRNKmKNqQB8VsuEXNf4DQ/suggest_brain.png" alt="suggest_brain.png" srcset="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmPEptCwARYt9Sa8mJD4S5e3iMRNKmKNqQB8VsuEXNf4DQ/suggest_brain.png 1x, https://images.hive.blog/1536x0/https://cdn.steemitimages.com/DQmPEptCwARYt9Sa8mJD4S5e3iMRNKmKNqQB8VsuEXNf4DQ/suggest_brain.png 2x" /><br /> The 16 words will hash into the owner private key, all keys can be derived from this key. It's similar to how hardware wallets like the Trezor or Ledger work, using a seed. <h1>Understanding how Private keys are hashed <p dir="auto">64 octet hex Private Key = Sha256 ( Sha512 (Password + Index)) <h1>Create an account from a brainkey <p dir="auto"><img src="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmS8ZEwmEAxuhxmxbwVSamENRz28BkLo9fDDsJVvkDvxTs/create1.png" alt="create1.png" srcset="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmS8ZEwmEAxuhxmxbwVSamENRz28BkLo9fDDsJVvkDvxTs/create1.png 1x, https://images.hive.blog/1536x0/https://cdn.steemitimages.com/DQmS8ZEwmEAxuhxmxbwVSamENRz28BkLo9fDDsJVvkDvxTs/create1.png 2x" /><br /> Syntax for creating an account with a brain key. We need the 16 words, an account name, and a faucet<br /> <img src="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmReaufph1rvn7sRzX847nnQ9AR6pUZCUYRsxLKwgyMfoU/create2.png" alt="create2.png" srcset="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmReaufph1rvn7sRzX847nnQ9AR6pUZCUYRsxLKwgyMfoU/create2.png 1x, https://images.hive.blog/1536x0/https://cdn.steemitimages.com/DQmReaufph1rvn7sRzX847nnQ9AR6pUZCUYRsxLKwgyMfoU/create2.png 2x" /> <p dir="auto">We now get presented with the results and this is where the problems come in, we now have an active key and a memo key, but we didn't get those private keys in our wallet!<br /> <img src="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmfUd728RhVW9yQ75FSYx7vEj6P1TRM7k34hmLuH4RUvGx/OAMkeys.png" alt="OAMkeys.png" srcset="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmfUd728RhVW9yQ75FSYx7vEj6P1TRM7k34hmLuH4RUvGx/OAMkeys.png 1x, https://images.hive.blog/1536x0/https://cdn.steemitimages.com/DQmfUd728RhVW9yQ75FSYx7vEj6P1TRM7k34hmLuH4RUvGx/OAMkeys.png 2x" /> <p dir="auto">In order to get these private keys we must derive them from our owner key which we were given earlier.<br /> <img src="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmUJwfedBZF8PzdXDdQozitpTsHbZXrMyvoE8FU4N24ohu/ownerkey.png" alt="ownerkey.png" srcset="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmUJwfedBZF8PzdXDdQozitpTsHbZXrMyvoE8FU4N24ohu/ownerkey.png 1x, https://images.hive.blog/1536x0/https://cdn.steemitimages.com/DQmUJwfedBZF8PzdXDdQozitpTsHbZXrMyvoE8FU4N24ohu/ownerkey.png 2x" /> <p dir="auto">Lets put that in the derive shell script attached at the end of this post<br /> <img src="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmNRKA4GWcY4HWETLUraZkQCt8NZpSCqAaaDdwtgYr7Ya3/derive.png" alt="derive.png" srcset="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmNRKA4GWcY4HWETLUraZkQCt8NZpSCqAaaDdwtgYr7Ya3/derive.png 1x, https://images.hive.blog/1536x0/https://cdn.steemitimages.com/DQmNRKA4GWcY4HWETLUraZkQCt8NZpSCqAaaDdwtgYr7Ya3/derive.png 2x" /><br /> Here we derive two keys, the first is the owner key at index 0, which is our active key, then we take the private key of the active key to derive the memo key. Additionally if you plan to be a witness/block producer, we can also derive our block signing key by using the active key at the index 1. If we have multiple witness nodes we can choose to derive more block signing keys from either the active key or from our block signing keys. <p dir="auto">Now lets import the keys into our wallet under our account, and we can double check by dumping the private keys<br /> <img src="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmW7BE9QGCJijy8xRzpJn6UReBuu3SuguNoCRpoaEtZ9L2/importdump.png" alt="importdump.png" srcset="https://images.hive.blog/768x0/https://cdn.steemitimages.com/DQmW7BE9QGCJijy8xRzpJn6UReBuu3SuguNoCRpoaEtZ9L2/importdump.png 1x, https://images.hive.blog/1536x0/https://cdn.steemitimages.com/DQmW7BE9QGCJijy8xRzpJn6UReBuu3SuguNoCRpoaEtZ9L2/importdump.png 2x" /><br /> Looks good, we now have the active key and the memo key added. It is a good security practice to not import the owner key and to keep it offline. By only importing the active and memo keys we can be sure if our wallet computer is compromised, we have not lost the owner key to the attacker. We can then use the owner key to change the accounts active and memo keys. <h1>The Linux Shell Script <h2>derive.sh <pre><code>#!/bin/bash PASSWORD=$1 SHA512=$(echo -n $PASSWORD|openssl dgst -sha512 -binary|xxd -c 512 -p) echo "SHA512:$SHA512" SHA256=$(echo -n $SHA512|xxd -r -p|openssl dgst -sha256 -binary|xxd -c 256 -p) echo "SHA256:$SHA256" EXTKEY="80$SHA256" CHECKSUM=$(echo -n $EXTKEY|xxd -r -p|openssl dgst -sha256 -binary|openssl dgst -sha256 -binary|xxd -c 256 -p|head -c 8) echo "CHECKSUM:$CHECKSUM" WIF=$(echo -n $EXTKEY$CHECKSUM|xxd -r -p|base58) echo "WIF:$WIF"