1. www. engineersportal.in

2. OUTLINES Network & Network Security Need of Network Security Methods of Network Security Firewall Firewall’s Works Firewall’s Importance Cryptography Cryptography’s Work Cryptography’s Importance RSA Algorithm RSA Algorithm’s Work RSA Algorithm’s Importance Importance of Network Security Maintenance of Network Security engineersportal.in

3. Network & Network Security Network:- A network is a group of two or more computer systems linked together. computer systems Network security :- Network security consists of the provisions and policies adopted by a network administrator to prevent and monitor unauthorized access, misuse, modification, or denial of a computer network and network- accessible resourcespoliciesnetwork administratorunauthorizedcomputer network engineersportal.in

4. Need Of Network Security The network needs security against attackers and hackers. Network Security includes two basic securities. The first is the security of data information i.e. to protect the information from unauthorized access and loss. And the second is computer security i.e. to protect data and to thwart hackers. Here network security not only means security in a single network rather in any network or network of networks. Now our need of network security has broken into two needs. One is the need of information security and other is the need of computer security. On internet or any network of an organization, thousands of important informations are exchanged daily. engineersportal.in

5. Methods Of Network Security Firewall RSA Algorithm Cryptography engineersportal.in

6. Firewall A technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts. engineersportal.in

7. Firewall’s Works Firewall acts like filter or you can say blocker in technical term which separate or blocks the unwanted information coming from the internet to enter the computers. By installing Firewall you can check the working of your employer and you can check the opening of the sites and exchange of information Firewalls have different methods to control the incoming data packets:- 1. Packet filtering 2. Stateful inspection 3. Proxy service engineersportal.in

8. Firewall Importance Whenever networking traffic is passed through the firewall it will decide exactly what to do. We can set the firewall up with a number of rules to block traffic from certain sources. A basic firewall will only handle incoming software but the best quality firewalls will also screen outgoing connections as well as incoming connections. The normal use for firewalls is to protect your computer from public networks such as the internet. Large companies will also need firewalls and antivirus applications and these can be hardware utilities instead of software tools. engineersportal.in

9. Cryptography Cryptography is one of the critical blocks, not only for Network Security, but also for all other areas of Information security, Cyber Security, OS Security, File System Security, Data Base Security, Web Security, Language Level security, Application level security, Wireless Security and Communications Security. engineersportal.in

10. Cryptography ‘s Work engineersportal.in

11. Cryptography’s Importance Some of the most Modern method of communication are inherently insecure. The internet is very insecure :- 1. Traffic passes through central hubs. 2. Like a giant party line. Ethernet networks liable to having sniffers. Cable modems pass through other people’s home. engineersportal.in

12. RSA Algorithm RSA is an algorithm for public-key cryptography that is based on the presumed difficulty of factoring large integers, the factoring problem. RSA stands for Ron Rivest, Adi Shamir and Leonard Adleman, who first publicly described it in 1977.algorithmpublic-key cryptographyfactoringlarge integersfactoring problemRon RivestAdi ShamirLeonard Adleman engineersportal.in

13. RSA Algorithm ‘s Works engineersportal.in

14. RSA Algorithm Importance A cryptographically strong random number generator, which has been properly seeded with adequate entropy, must be used to generate the primes p and q. An analysis comparing millions of public keys gathered from the Internet was recently carried out by Lenstra, Hughes, Augier, Bos, Kleinjung, and Wachter. They were able to factor 0.2% of the keys using only Euclid's algorithm. [15][16] They exploited a weakness unique to cryptosystems based on integer factorization. If n = pq is one public key and n' = p'q' is another, then if by chance p = p', then a simple computation of gcd(n,n' ) = p factors both n and n', totally compromising both keys. Lenstra et al. note that this problem can be minimized by using a strong random seed of bit-length twice the intended security level, or by employing a deterministic function to choose q given p, instead of choosing p and q independently. Nadia Heninger was part of a group that did a similar experiment. They used an idea of Daniel J. Bernstein to compute the GCD of each RSA key n against the product of all the other keys n' they had found (a 729 million digit number), instead of computing each gcd(n,n') separately, thereby achieving a very significant speedup. (After one large division the gcd problem is of normal size.) Heninger says in her blog that the bad keys occurred almost entirely in embedded applications, including "firewalls, routers, VPN devices, remote server administration devices, printers, projectors, and VOIP phones" from over 30 manufactures.random number generatorEuclid's algorithm [15][16]Daniel J. Bernstein engineersportal.in

15. Importance Of Network Security engineersportal.in

16. Maintenance Of Network Security engineersportal.in