Encryption Vs Cryptographic Hash
Encryption vs Cryptographic Hash#
What is the difference between encryption and a cryptographic hash
Create a secret message to send to someone and they do the opposite to decrypt it. Encryption can always be reversed if you know the process or have the correct key.
Hashing is a process that cannot be undone. It always changes the same input into the same output. It is one way and usually creates output of a specific size. eg. 256 bits.
Cryptographic hashing adds random data, a
salt, that makes the input data more different and unique.
Example Using Bcrypt#
pip install flask-bcrypt
from flask_bcrypt import generate_password_hash
Generate the hash
$2btells you it is
$12is the number of rounds
- rest is the hash
If you set the rounds really high, it takes longer:
>>> generate_password_hash('secret', 15)
When a password attempt fails, it is good practise to increase the rounds so it takeslonger to check the hash.Slowing down crackers.
How do you heck it though…
>>> hashed_pw = generate_password_hash('secret', 12) >>> hashed_pw b'$2b$12$tE/SrlIDeO3Efs5lI77ZxeY3hzoAd1on2Lbx0SZnxBEARuSwBvEri' >>> hashed_pw == generate_password_hash('secret', 12) False
The above does not work.
Youhave to check it with
from flask_bcrypt import check_password_hash
then test it:
>>> check_password_hash(hashed_pw, 'secret')