What are hash functions and how do they ensure security?

What are hash functions and how do they ensure security?

Hash functions are algorithms that convert input data into a fixed-size string of characters, which is typically a hash code. They are crucial for data integrity and security.

Can you explain how they are used in password storage?

Certainly! When storing passwords, systems use hash functions to convert the password into a hash. This way, even if the database is compromised, the actual passwords are not exposed.

What makes a hash function secure?

A secure hash function should be collision-resistant, meaning it's hard to find two different inputs that produce the same hash. It should also be pre-image resistant, making it difficult to reverse-engineer the original input from the hash.

Are there any common hash functions that are considered insecure?

Yes, some older hash functions like MD5 and SHA-1 have known vulnerabilities and are considered insecure for cryptographic purposes.