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What is a Block?

🔐 Turn Any Data Into a Digital Fingerprint

Discover how one-way cryptographic functions create unique identifiers for any data

🔐 What is Hashing?

A hash function is a mathematical algorithm that takes any input and produces a fixed-size output called a hash. It's like a digital fingerprint for data.

🎯 Core Concept

Think of hashing like turning a book into a unique barcode. No matter how long the book is, the barcode is always the same size. Change even one letter in the book, and you get a completely different barcode.

Input: "Hello Blockchain"
↓ SHA-256 Hash Function
Output: 3d5f8a7b2c1e9f4d...

🔬 Try It Yourself!

Type anything below and watch the hash change instantly:

Type something to see the hash...
📏

Fixed Size

No matter how long your input is, the hash is always the same length (256 bits for SHA-256).

Fast Computation

Hash functions process data quickly, even for massive files or long text strings.

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Deterministic

The same input always produces the same hash. Hash "Hello" a million times, you'll get the same result.

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One-Way Function

You can't reverse a hash to get the original input. It's impossible to "unhash" something.

🔗 Why Blockchain Needs Hashing

  • Block Linking: Each block's hash links it to the previous block, creating an unbreakable chain
  • Data Integrity: Any change to block data produces a completely different hash, making tampering obvious
  • Mining: Proof of Work requires finding specific hash values, which takes computational effort
  • Addresses: Wallet addresses are derived from hashes of public keys