Questions

Why is hash function security crucial ?

Hash functions are used in a very large scope nowadays. Data security, data integrity, authentication, crypto-currencies...

What are hash algorithms ?

A cryptographic hash function is an algorithm (sequence of mathematic and cryptographic operations) that takes an arbitrary amount of data and produces a fixed-size output of enciphered text called a hash. They are usually used to secure an information transfer between two computer system. Hash functions allow mainly to confirm some properties of an IT message, such as its destination, its origin, or just to make the difference between two similar items without revealing its content.

How does it work ?

From Davies-Meyer's function to the Merkle tree, trough the one-way compression function.

What are the attacks against cryptographic hash functions ?

Many attacks exist to try to break cryptographic hash functions. Some of them can successfully break a hash function, others are currently technically impossible to accomplish.

Experiment with cryptographic hash functions.

Understand cryptographic hash functions, experiment on their use, try hash functions breaking tools.