Hashing
Definition
Hashing is the process of transforming any given key or a string of characters into another value. This is usually a fixed-length string or number that represents the original string. A good hash function is one-way, meaning the original data cannot be retrieved from the hash.
Why It Matters
Hashing is crucial for data integrity and password storage. By comparing the hashes of two pieces of data, you can verify if they are identical without having to see the data itself.
Contextual Example
When you create a password for a website, the site doesn't store your actual password. It stores a hash of your password. When you log in, the site hashes the password you enter and compares it to the stored hash. If they match, you are authenticated. This way, even if the database is stolen, the attackers don't get your actual password.
Common Misunderstandings
- Hashing is not encryption. You cannot "decrypt" a hash to get the original data back.
- SHA-256 and MD5 are examples of hashing algorithms, though MD5 is now considered insecure.