What is SHA-256 and Why Should You Care About Document Integrity?

In today’s digital world, almost everything we create, share, and store is electronic. From contracts and medical records to creative projects, the authenticity of these files is critical. That’s where SHA-256 comes in.

SHA-256 is a cryptographic hash function—think of it as a digital fingerprint for a file. No matter the size of the document, SHA-256 creates a unique 256-bit string (a series of numbers and letters). If even a single character in the file changes, the resulting hash changes completely.

Why it matters

• Tamper detection: If a hacker or malicious actor modifies a file, even slightly, the hash won’t match anymore.
• Trust: When two parties share documents, both can independently compute the hash and confirm they match, building confidence in authenticity.
• Longevity: Documents stored for years can be re-hashed to ensure they haven’t been altered or corrupted by disk errors.

Real-world examples

• Software downloads often publish SHA-256 checksums so users can ensure they are installing unaltered programs.
• Legal professionals use hashing to preserve the integrity of digital evidence.
• Blockchain technology relies on SHA-256 to secure transaction records.

Constantly verifying integrity with SHA-256 isn’t paranoia—it’s smart digital hygiene.