Dictionary · Cybersecurity Fundamentals
Hashing
Cryptography · Beginner
A one-way calculation that maps data to a fixed-length fingerprint. A small change in the input should completely change the fingerprint, and the input is not restored from it.
You store or publish the fingerprint when you need to detect change, or when you need to check a password without keeping the password itself. It is not encryption.
Example: A website stores a salted hash of a password. The password cannot be read back out of that stored value.
Common misconception
- A hash is not a compressed copy of the file. You cannot decrypt it back to the original.