Cryptography - Past, Present and Future

Welcome to Section 2 on historical secret-key cryptography

The concept of secret key cryptography

Encryption using the Vigenere cipher

Decryption using the Vigenere cipher

How to break the Vigenere cipher

Using Kasiski testing to help break the Vigenere cipher

Encryption using the Playfair cipher

Decryption using the Playfair cipher

Welcome to the third section on 20th century ciphers

Understand the concept behind the one-time pad

Be able to encrypt and decrypt using the one-time pad

Understand why the one-time pad has flaws, even though it is theoretically perfect.

Appreciate the importance of mechanical machines in cryptography, in particular the Enigma machine

Welcome to Section 4, on modern methods DES and AES

Use XOR on two binary strings and understand the relevance of binary numbers in computing

Understand the difference between stream and block ciphers

Appreciate the importance of DES in the introduction of cryptography into the mainstream and an understanding of why it was so revolutionary at the time.

Understand how DES is actually implemented in practice

Understand how DES was broken as computing power grew.

The background behind that a new cipher was needed to replace DES

The basic operation of AES

Why AES is currently considered secure

Welcome to Section 5 on public-key cryptography

Understand the concept of public-key cryptography and appreciate the difference between secret-key cryptography

Understand the concept of primitive roots (mod p) for a prime number p

Understand and be able to use the Diffie-Hellman key exchange method

Understand that Diffie-Hellman was a completely new cryptographic experience and appreciate why, despite its new techniques, it was still flawed at the time as it did not contain any authentication.

Welcome to Section 6 covering the RSA algorithm

Use and understand Euler's totient function

The essential background behind the RSA algorithm

How the private and public keys are set up for use in RSA

The full description as to how RSA works

Understand the background, usefulness and current implementation of RSA

Welcome to Section 7 on public-key infrastructures

The basic concept of PKI (public-key infrastructures) and why it is relevant today.

Understand hashing in that it is a one-way process that should not be possible to recover the original text, as opposed to cryptography when we intend to be able to recover the original message.

Understand the basic idea as to how digital signatures work in order to create a secure environment for communication.

Be aware of digital certificates and be able to find the certificate authority path of a website.

Appreciate how everything comes together to create the secure system that we currently live in.

Section 8 on current cryptographic issues

Understand how linear feedback shift registers (LFSRs) operate and can be used to generate pseudo-random strings

How steganography differs from cryptography in that it hides the existence of a message, and its use in digital images

Appreciate the use of cryptography in digital watermarking, for example to copyright files.

The basic idea of cryptocurrency and its uses in providing anonymous transactions

The mathematical basics behind elliptic curves

Why elliptic curves can be relevant in modern-day cryptography because of its speed and security

Understand various cryptographic attacks and be aware of the mulitple methods that a hacker might use

Welcome to Section 9 looking at the future and the possible use of quantum mechanics in cryptography

Understand the basic concepts of quantum computing and how it may affect current algorithms such as RSA

Be able to use Shor's Algorithm and understand that it is technically fast if used on a quantum computer

A discussion of how quantum cryptography works and its potential for the future

Summary of the course material

How to get a certificate of completion of the course.