Python 3 - Second Edition

26.5    Hash Functions: hashlib

The hashlib module of the standard library implements the most common hash functions. A hash function is a complex algorithm that calculates a hash value from a parameter, usually a string. What can such a hash value be used for? In this section, we walk through a practical example that has been simplified[ 122 ] for presentation purposes.

Imagine you are developing forum software that will later be used for a community on the internet. Before users may post to the forum, they must log in with a user name and the relevant password. Of course, it’s in the interest of the forum operator and especially the users themselves that the password doesn’t fall into the wrong hands. The question therefore is how to make ...