1. SAMET KARTAL 2011514038

2. No one wants to share own information with unknown person. Sometimes while sharing something with someone people wants to keep it safe and secret. At this technology age almost all information is sharing with internet For this reason ‘’ Network Security’’ is the most important topic for the internet users

3. Someone wants to get your emails. Hackers wants to get your credit card numbers. Sometimes someone wants to get your special information Sometimes someone wants to get your companies project Sometime some countries get some war plans from enemy country Etc….

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6. A firewall is a network security system, either hardware- or software-based, that controls incoming and outgoing network traffic based on a set of rules. A Virtual Private Network (VPN) is a network technology that creates a secure network connection over a public network such as the Internet or a private network owned by a service provider.

8. Encrypting and decrypting event is happening is this layer Hided with some rules data is going to another machine and opening to there

9. Firewalls and some anti-virus programes are detecting package that harmfull or not

10. Transport Layer Security (TLS) which is frequently referred to as 'SSL', are cryptographic protocols that provide communications security over a computer network. Several versions of the protocols are in widespread use in applications such as web browsing, email, internet faxing, instant messaging, and voice-over-IP (VoIP). Major web sites use TLS to secure all communications between their servers and web browsers.

11. After passing all layers at last data will be shown on computer after authentication Cryptography is using on this layer

12. Cryptography is a method of storing and transmitting data in a particular form so that only those for whom it is intended can read and process it Simply you will change your data with some rules and make it impossible to can be seen without your changing rules

14. Everything will encrypting according to your algorithmes and sending other computer If it has your algorithme key, data will be decrypted

16. Phishing Spyware Virus Worms

17. Phishing is a form of fraud in which the attacker tries to learn information such as login credentials or account information by masquerading as a reputable entity or person in email, IM or other communication channels

18. Spyware is a type of malware that is installed on a computer without the knowledge of the owner in order to collect the owner’s private information. Spyware is often hidden from the user in order to gather information about internet interaction, keystrokes (also known as keylogging), passwords, and other valuable data

19. A computer virus is a program to cause damage, steal personal information, modify data, send e-mail, display messages, or some combination of these actions. When the virus is executed, it spreads by copying itself into or over data files, programs, boot sector of a computer's hard drive, or potentially anything else writable. Virus writers use detailed knowledge of security vulnerebilities to gain access to a host's computer.

20. A computer worm is a self-replicating computer program that penetrates an operating system with the intent of spreading malicious code. Worms utilize networks to send copies of the original code to other computers, causing harm by consuming bandwidth or possibly deleting files or sending documents via email. Worms can also install backdoors on computers.

21. http://www.computerhope.com/jargon.htm https://www.sibergah.com/uc-nokta-guvenligi/cihaz- guvenligi/bilgisayar-guvenligini-tehdit-eden-temel- nedenler/ https://www.sibergah.com/uc-nokta-guvenligi/cihaz- guvenligi/bilgisayar-guvenligini-tehdit-eden-temel- nedenler/ https://www.sibergah.com/genel/bilgi-guvenligi- nedir-ve-nasil-siniflandirilir/ https://www.sibergah.com/genel/bilgi-guvenligi- nedir-ve-nasil-siniflandirilir/ https://en.wikipedia.org/wiki/Network_interface_laye r_security https://en.wikipedia.org/wiki/Network_interface_laye r_security

22. http://searchsoftwarequality.techtarget.com/definitio n/cryptography http://searchsoftwarequality.techtarget.com/definitio n/cryptography http://www.webopedia.com/TERM/F/firewall.html https://en.wikipedia.org/wiki/Virtual_private_networ k https://en.wikipedia.org/wiki/Virtual_private_networ k