National Institute of Applied Science and

Technology

Blockchain Practical Work

Ethereum Private Blockchain Setup

Student :
Ali Doggaz, Salma Borchani, Achref Level :
Saidi, Salem Hamdani, Mahdi 5éme Génie Logicielle
Ghorbel
TABLE DES MATIÈRES Table des matières

Table des matières

1 Introduction 2

2 Environment Setup 2
2.1 Installing Ethereum Client (Geth) . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Creating Directories for Miners . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Genesis Block Configuration 4

3.1 Creating the Genesis File . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

4 Blockchain Initialization 5
4.1 Initializing Miner Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5 Creating Accounts 6
5.1 Account Creation for Miner #1 . . . . . . . . . . . . . . . . . . . . . . . . 6

6 Mining Process Setup 8

6.1 Preparing and Running Miner . . . . . . . . . . . . . . . . . . . . . . . . . 8

7 Account Management and Transactions 10

7.1 Viewing Account Balances . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.2 Sending Transactions within Miner #1 . . . . . . . . . . . . . . . . . . . . 11

8 Inter-Miner Transactions 11
8.1 Sending Ethers between Miner Nodes . . . . . . . . . . . . . . . . . . . . . 11

9 Conclusion 13

A Appendix : Script Files 13

A.1 startminer1.sh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
A.2 startminer2.sh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Rapport - Ethereum Private Blockchain Setup 1

 2 Environment Setup

1 Introduction
In this report, we document the setup process for creating a private Ethereum blo-
ckchain, including installing dependencies, configuring nodes, and testing transactions.
Screenshots of key steps are provided.

2 Environment Setup
2.1 Installing Ethereum Client (Geth)
To install the Ethereum client Geth, we used Homebrew (Mac).

Figure 1 – Installing Geth

Note : After noticing that the latest version isn’t working properly, we had to change
the version on geth. As I am using MAC OS, I had to install the tar package manually of
the correct stable version on Mac.

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2.1 Installing Ethereum Client (Geth) 2 Environment Setup

Figure 2 – Geth version

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2.2 Creating Directories for Miners 3 Genesis Block Configuration

2.2 Creating Directories for Miners

Here is the content of the genesis file, with the 3 appropriate EIPs :

Figure 3 – Genesis.json

Separate directories are created for each miner to store blockchain data :

Figure 4 – Directory Structure

3 Genesis Block Configuration

3.1 Creating the Genesis File
A genesis file is created to initialize the blockchain with specific parameters.

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 4 Blockchain Initialization

Figure 5 – creation of genesis.json

4 Blockchain Initialization
4.1 Initializing Miner Nodes
Each miner node is initialized with the genesis block :
cd ~/ C h a i n S k i l l s
g e t h −−d a t a d i r ~/ C h a i n S k i l l s / miner1 i n i t g e n e s i s . j s o n
g e t h −−d a t a d i r ~/ C h a i n S k i l l s / miner2 i n i t g e n e s i s . j s o n

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 5 Creating Accounts

Figure 6 – Miner 1 Init

Figure 7 – Miner 2 Init

5 Creating Accounts
5.1 Account Creation for Miner #1
The default account for Miner #1 is created using :

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5.1 Account Creation for Miner #1 5 Creating Accounts

g e t h −−d a t a d i r ~/ C h a i n S k i l l s / miner1 account new

g e t h −−d a t a d i r ~/ C h a i n S k i l l s / miner1 account new

g e t h −−d a t a d i r ~/ C h a i n S k i l l s / miner2 account new

g e t h −−d a t a d i r ~/ C h a i n S k i l l s / miner2 account new

Figure 8

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 6 Mining Process Setup

6 Mining Process Setup

6.1 Preparing and Running Miner
A password file is created for Each Miner’s default account :
echo " t e s t 1 2 3 " > ~/ C h a i n S k i l l s / miner1 / password . s e c
Miner #1 is then started using our bash script :

Figure 9 – Startminer script

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6.1 Preparing and Running Miner 6 Mining Process Setup

Figure 10 – Miner Running

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 7 Account Management and Transactions

Figure 11 – JS console

7 Account Management and Transactions

7.1 Viewing Account Balances
Using the Geth console, the balances of each account can be viewed :
e t h . g e t B a l a n c e ( et h . c o i n b a s e )

Figure 12 – Display Balance of miner 1 and 2

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7.2 Sending Transactions within Miner #1 8 Inter-Miner Transactions

7.2 Sending Transactions within Miner #1

A test transaction is sent from account #0 to account #1 :
e t h . s e n d T r a n s a c t i o n ( { from : et h . a c c o u n t s [ 0 ] , t o : et h . a c c o u n t s [ 1 ] , v a l u e : web

8 Inter-Miner Transactions
8.1 Sending Ethers between Miner Nodes
To verify communication between the nodes, 5 ethers are sent from Miner #1 to Miner
#2’s account :
e t h . s e n d T r a n s a c t i o n ( { from : et h . c o i n b a s e , t o : ’ [REPLACE␣WITH␣ADDRESS␣OF␣ACCO

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8.1 Sending Ethers between Miner Nodes 8 Inter-Miner Transactions

Figure 13 – Sending Transaction

Figure 14 – New Balances

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 A Appendix : Script Files

9 Conclusion
The private Ethereum blockchain was successfully set up with two miner nodes ca-
pable of managing accounts, conducting transactions, and mining ethers in a controlled
environment. This setup demonstrates the fundamental process of blockchain creation
and management on a local network.

A Appendix : Script Files

A.1 startminer1.sh
#! / b i n / b ash
g e t h −−i d e n t i t y miner1 −−n e t w o r k i d 42 −−d a t a d i r / U s e r s / a l i d o g g a z /TP1_BlockC
−−n o d i s c o v e r −−mine −−r pc −−r p c p o r t 8042 −−p o r t 30303 −−u n l o c k 0 −−pas
−−i p c p a t h / U s e r s / a l i d o g g a z /TP1_BlockChain/ C h a i n S k i l l s / miner1 / g eth . i p c
−−a l l o w −i n s e c u r e −u n l o c k "

A.2 startminer2.sh
#! / b i n / b ash
g e t h −−i d e n t i t y miner2 −−n e t w o r k i d 42 −−d a t a d i r / U s e r s / a l i d o g g a z /TP1_BlockC
−−n o d i s c o v e r −−mine −−r pc −−r p c p o r t 8043 −−p o r t 30304 −−u n l o c k 0 −−pas
−−i p c p a t h / U s e r s / a l i d o g g a z /TP1_BlockChain/ C h a i n S k i l l s / miner2 / g eth . i p c
−−a l l o w −i n s e c u r e −u n l o c k "

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