The following slides are from the **Spring****
lectures** delivered during Semesters B of the Session 2017-2018.

Lecture 1 |
Cyber Security: · Aspects of Cryptography from a Classical and Quantum Perspective · Definitions, Properties, Standard Threat Model, · Symmetric key ciphers: Vernam (One Time Pad), DES, AES, … · Asymmetric key ciphers:, Diffie-Hellman, RSA, El Gamal |

Lecture 2 |
Asymmetric Key Schemes: · The Integer Factorisation Problem (IFP), RSA · Encryption, Decryption and Digital Signatures |

Tutorial 1 & 2 |
Security 1 and Answers |

Lecture 3 |
Cyclic Groups, Primitives, Orbits, and the Integer Factorisation Problem Cyclic Groups, Primitives, Orbits, and the Discrete Logarithm Problem (DLP) Groups, Subgroups, Diffie-Hellman and the El Gamal Algorithm. |

Lecture 4 |
El Gamal Algorithm – Encryption and Decryption El Gamal Algorithm (+ Answers) |

Tutorial 3 & 4 |
Security 2 A and Answers Security 2 B and Answers |

Lecture 5 |
Discussion on Answers to Security 2 A |

Lecture 6 |
Key Exchange (using RSA) and Key Agreement (using Diffie Hellman) The Diffie-Hellman Protocol and El Gamal (Encryption and Decryption) DES The Data Encryption Standard and sub-Key Algorithm |

Tutorial 5 & 6 |
Security 3 and Answers Security 4 and Answers |

If you have any queries then you can email me on j.spring@herts.ac.uk

Updated 28^{th} February 2018.