SHA-2 (Secure Hash Algorithm 2) is a family of cryptographic hash functions commonly used to protect data in computer systems, especially in cybersecurity, authentication, and digital signatures.

🧠 What SHA-2 Is

SHA-2 transforms input data (like a password, file, or message) into a fixed-length string of characters known as a hash. Even the tiniest change in the input produces a totally different hash, which helps verify the integrity and authenticity of data.

📚 SHA-2 Family Members

SHA-2 includes several different algorithms based on output size:

• SHA-224: Generates a 224-bit hash
• SHA-256: Generates a 256-bit hash (widely used)
• SHA-384: Generates a 384-bit hash
• SHA-512: Generates a 512-bit hash
• SHA-512/224 and SHA-512/256: Variants with different output lengths

🔐 Why SHA-2 Is Important

• Security: Unlike older versions like SHA-1 (which is now considered broken), SHA-2 is much more resistant to attacks such as collision and preimage attacks.
• Verification: Commonly used to check if downloaded files are unaltered and authentic.
• Digital Signatures: Used in certificates, like HTTPS on websites, to verify identity and secure communication.

🧪 Example Use Case

Input: "Hello World"
SHA-256 Hash: a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e

Change just one letter, and the entire hash changes—like a digital fingerprint!