Blockchain-demo

Blockchain-demo is an implemtation of the blockchain-data-structure and a small simulation how the blockchain
works.See wiki section for more details

Prerequisites

• python3 should be installed.

• Installing needed python modules:

pip install -r requirements.txt

Running

cd Blockchain-demo/

• Generating asymmetric cryptography to be used in transactions:
  ```python
  from utils.encryption import *
  person_1 = generate_encryption_keys()
  person_2 = generate_encryption_keys()

**generate_encryption_keys()** return a dictionnary object with *public_key* and *private_key* as keys.
Note that the dictionnary values are respectively **RSAPublicKey** and **RSAPrivateKey** objects from the **cryptography** module.
* Making a transaction : *person_1* sends something to *person_2*: 
```python
from transaction import Transaction
tr_1 = Transaction(sender=person_1["public_key"], receiver=person_2["public_key"], assets="SOMETHING")
tr_1.sign(person_1["private_key"])

A transaction must be signed with sign() methods in order to be valid.
The is_valid() method can be used to verify wether a transaction object is valid or not.

tr_1.is_valid()
True

Now, we will create a block that holds the transaction.

from block import Block
bl_1 = Block(tr_1)

To be a valid block (also to be added to the blockchain), a proof of work is required.
mine() method will find a solution to the hash puzzle according to a difficulty level.

bl_1.mine()

Creating a Blockchain and adding a block..

from blockchain import Blockchain
blc = Blockchain()
blc.add_block(bl_1)

show_blocks() can be used to print all blocks in the blockchain.

from blockchain import Blockchain
blc.show_blocks()