> ## Documentation Index
> Fetch the complete documentation index at: https://docs.theblockchainlibrary.com/llms.txt
> Use this file to discover all available pages before exploring further.

# SHA-256

> A 256-bit cryptographic hash function from the SHA-2 family, used extensively in Bitcoin and security systems.

# SHA-256

A 256-bit cryptographic hash function from the SHA-2 family, used extensively in Bitcoin and security systems.

## Definition

A 256-bit cryptographic hash function from the SHA-2 family, used extensively in Bitcoin and security systems.

## Why it matters

Cryptography provides the mathematical foundation for keys, signatures, privacy, integrity, and verification.

## How it works

The algorithm processes the input data through multiple rounds of logical, bitwise operations. It compresses the data into a fixed-length string of hexadecimal numbers. The design ensures that even a tiny alteration in the source results in a drastically different, unpredictable output hash.

## Real-world example

Bitcoin mining and the SHA-256 hashing standard used by the TLS protocol for secure web traffic.

## Advantages

* Strong collision resistance
* High data integrity
* Computational efficiency

## Limitations

* Vulnerable to massive brute-force attacks
* Not suitable for password storage alone
* Quantum computing threats

## Common misconceptions

* Many people incorrectly call it an encryption algorithm, but it is actually a one-way hash function.
* Some mistakenly believe it can be decrypted to reveal the original input.

## Related knowledge

* [Hash Function](/generated/v2/glossary/hash-function) — term

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**Canonical knowledge ID:** `glossary:sha-256`