What are hash functions and how do they ensure data integrity?

What are hash functions and how do they ensure data integrity?

Hash functions are algorithms that convert input data into a fixed-size string of characters, which is typically a hash code. They ensure data integrity by producing a unique hash for each unique input; even a small change in the input will result in a completely different hash.

Can you give me an example of how hash functions are used in practice?

Sure! One common use of hash functions is in storing passwords. Instead of saving the actual password, systems store the hash of the password. When a user logs in, the system hashes the entered password and compares it to the stored hash.

What happens if two different inputs produce the same hash?

This scenario is known as a hash collision. While it's theoretically possible, good hash functions are designed to minimize collisions, making it extremely unlikely for two different inputs to produce the same hash.

Are there different types of hash functions?

Yes, there are several types of hash functions, including MD5, SHA-1, and SHA-256. Each has different properties and levels of security, with SHA-256 being widely used for its robustness.