Hello Students, I have created this course for your Learning in easy way. I hope when you take this course you will be master at the end. In this course you will learn about Clod Computing, Network Security, Attacks, Cryptography, IPsec, Pretty Good Privacy(PGP), Virtual Private Network. I have created this course for all level students. Its also simple and advance. Basically Cloud Computing sometimes called Distributed System. Here are some examples of distributed system: Local Area Network and Intranet, Database Management System, Automatic Teller Machine Network, World Wide Web and mobile computing. In first Lecture, we will discuss about what is distributed system, Examples of Distributed System, Common Characteristics, Basic Design Issues. In Second Lecture we will discuss about introduction to network security, Secure channels/ Network Layers, Analysis of Protocols, Standards, Web Security DNS security. In next Lecture we will discuss all about Cryptography. In next Lecture we will discuss about Malicious Codes, Viruses. In next lecture we will discuss about Virtual Private Network, its Protocols, Categories of VPN, VPN Topologies, VPN Components, Security. In next Lecture, we will discuss about Firewalls, Packet Filtering, Gateways, Firewall Architecture. In next lecture, we will discuss about Digital Signatures, Properties. In next lecture we will discuss about Kerberos, benefits, advantages and disadvantages of Kerberos. In next lecture we will discuss about Certificates, Authentication with certificates, how to setup client certificates. In next lecture we will discuss about IPsec, SA(Security Association), Necessary Components. In next lecture we will discuss about Key Management in Cryptography, Key Management Techniques, Life Cycle. In next lecture, we will discuss about Pretty Good Privacy(PGP), Schemes of PGP.