Implementing-cryptography-using-python

8 Chapter 1 ■ Introduction to Cryptography and Python
The Cryptography package includes both high-level recipes and low-level
interfaces to common cryptographic algorithms such as symmetric ciphers, message
digests, and key derivation functions. For example, to encrypt something
with Cryptography’s high-level symmetric encryption recipe, use this:
>>> from cryptography.fernet import Fernet
>>> # Put this somewhere safe!
>>> key = Fernet.generate_key()
>>> f = Fernet(key)
>>> token = f.encrypt(b"A really secret message. Not for prying eyes.")
>>> token
'...'
>>> f.decrypt(token)
'A really secret message. Not for prying eyes.'
Installing Additional Packages
IPython is available through many providers; it is an enhanced, interactive
version of Python. IPython offers a combination of convenient shell features,
special commands, and a history mechanism for both input and output. IPython
offers a vastly improved set of functionality and flexibility; it is a fully compatible
replacement for the standard Python interpreter. You can install IPython
by typing the following:
sudo apt install IPython3
apt-get install python3-IPython
To use IPython, type IPython3 -h at the system command line. You can start
the shell by typing this:
~$ IPython3
You should see something similar to the following:
Python 3.5.3 (default, Sep 27 2018, 17:25:39)
Type "copyright", "credits" or "license" for more information.
IPython 5.1.0 -- An enhanced Interactive Python
In [1]:
Please note that you will need to pay attention to the version of Python; this
example is using Python 3.5.3, but you may see something like Python 2.x if you
did not specify IPython3. When Python 3 first came out, many libraries didn’t
exist, so many people stayed with 2.x. Python 3 has caught up and is now a
great language. There are, however, a few differences between Python 2.x and
Python 3, so if you find that some of your scripts fail, try running them using
an alternate version.