juniorCryptography

What is a Hash Function?

Updated Apr 28, 2026

Short answer

A hash function maps data of arbitrary size to a fixed-size bit string, which is typically a message digest.

Deep explanation

At a junior level, understanding the CIA triad (Confidentiality, Integrity, Availability) is crucial. Cryptography primarily addresses Confidentiality through encryption and Integrity through hashing and digital signatures.

Real-world example

Using HTTPS while browsing the web utilizes TLS to encrypt traffic between your browser and the server.

Common mistakes

  • Confusing Base64 encoding with encryption.

Follow-up questions

  • Can you reverse a hash?
  • What makes a password 'strong'?

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