What is SHA-256? Learn SHA-256 in one minute

What is SHA-256?

SHA-256, commonly pronounced sha-two-fifty-six, is a cryptographic hash function designed by the National Security Agency (NSA). It is one of the most widely used hash functions today. Here's a simple explanation of SHA-256:

1. Input: SHA-256 takes an input of any size, typically a message, file, or string of data.
2. Processing: The input is divided into 512-bit blocks. Each block undergoes multiple rounds of hashing using a complex mathematical algorithm.
3. Output: After processing all the blocks, SHA-256 produces a fixed-length output called a "fingerprint" or "hash," represented as a 256-bit hexadecimal number.
4. Deterministic: SHA-256 is deterministic. This means that providing the same input always produces the same hash.
5. Cryptographic: SHA-256 is a cryptographic hash function. It is designed to be irreversible. It is computationally infeasible to determine the original input from the hash.

6. Applications: SHA-256 is used in a wide range of applications, including:

   a. Password protection: Hashing passwords provides a secure way to store user passwords without storing the plaintext versions.

   b. Digital signatures: SHA-256 is used to create digital signatures that verify the authenticity and integrity of digital documents.

   c. Blockchain and Cryptocurrency: SHA-256 is utilized in blockchain technology to secure transactions and create unique cryptocurrency addresses.

   d. File verification: SHA-256 can be used to verify the integrity of files by comparing their hashes before and after transmission or storage.