Hashing and Smart Contracts

What is hash ?

• It is a unique digital fingerprint of any data

• It is created using hash function

• It is deterministic

• A small change in input will change the output completely.

What are the uses of hash in blockchain?

• Generation of hash code

• Mekel tress

• Data integrity

Diagram of Hash :

What are the properties of a secure cryptography hash function?

1. Collision Resistance – No two different inputs should produce the same hash.

2. Preimage Resistance – A hash output should not reveal its original input.

3. Deterministic Output – The same input always produces the same hash.

4. Avalanche Effect – A small input change causes a completely different hash.

5. Puzzle Friendliness – Finding an input that produces a specific hash should be computationally hard.

6. Fixed-Length Mapping – The hash output is always of a fixed size, regardless of input length.

What are smart contracts?

A smart contract is a program that automatically executes when conditions are met

ex: vending machine, voting system

Working of smart contract

It follows IFTTT logic : If this, then that

If runs on a blockchain and execute itself when conditions are met

What are the steps of smart contracts?

• Write the code: Define the condition using programming language

• Deploy on Blockchain: Upload the contract to BC

• Wait for trigger

• Automatic execution

• Record transaction