![esecurity](https://raw.githubusercontent.com/billbuchanan/esecurity/master/z_associated/esecurity_graphics.jpg)
# 2. Symmetric Key Encryption

## Outline
The key concepts involved in this unit are:

* Defining key entropy; 
* Key generators (such as using hashing methods to generate keys based on passphrases); 
* Symmetric key methods (AES, Twofish, 3DES, RC4 and ChaCha20); 
* Stream or block encryption; 
* Symmetric key modes (ECB/CBC/OFB); 
* Salting/IV.


## Presentations

* Week 2 Presentation (PDF) - Symmetric Key Encryption: [here](https://asecuritysite.com/public/chapter02_secret.pdf)
* Week 2 Presentation (Video) - Symmetric Key Encryption [here](https://youtu.be/nLRV34K3xIo)
* Week 2 Presentation (Lecture - Video) - Symmetric Key Encryption: [here](https://youtu.be/CCOt8Xk3ZVU). Recorded on Friday 24 Jan 2020.


## Videos
The voice over lecture is here:

[![](http://img.youtube.com/vi/nLRV34K3xIo/0.jpg)](https://www.youtube.com/watch?v=nLRV34K3xIo "")

And the classroom lecture from 24 Jan 2020 is here:

[![](http://img.youtube.com/vi/CCOt8Xk3ZVU/0.jpg)](https://www.youtube.com/watch?v=CCOt8Xk3ZVU "")