Hash

📝 Definition:

A hash is a special code created from data.

It turns any kind of data (like text or files) into a fixed-length string of characters.

It’s like a digital fingerprint for information, making it easy to check if the data has changed.

🔑 Key Features:

1. Fixed Output: No matter how big or small the data is, the hash always has the same number of characters.
2. Consistency: The same data will always produce the same hash.
3. Speed: Hashes are made quickly, making them good for checking data fast.
4. Unique: It’s very hard to find two different sets of data that create the same hash.

⚙️ How It Works:

1. Input Data: Any data, like a document or a photo.
2. Hash Function: This is a tool that takes the data and converts it into a hash.
3. Unique Output: Even a small change in the data will create a completely different hash.

💡 Applications:

1. Data Integrity: Guaranteeing that files or messages haven’t been changed.
2. Cryptography: Protecting data by turning it into a code.
3. Blockchain: Linking blocks of data in a blockchain securely.
4. Password Storage: Storing passwords securely by hashing them.

🔍 Example:

Imagine you have a long piece of text.

When you run it through a hash function, you get a unique string of characters.

If you change even one letter in the text, the hash will be completely different.

This helps ensure that the original data hasn’t been changed.