Advanced Information Security

Viewing Web pages: For the web pages, the imposter could appeal off a phishing attack, tricking users into thinking that they were accessing their bank's Web site, and hence pull off a man-in-the-middle attack and gather login credentials. Moreover, they are accessing some personal data or putting some personal data on some website and hence pull off a man in the middle attack and collect all the personal details of this user. Why, in practice, are server certificates rarely signed: It appears to be too much trouble to distribute the public keys securely for the certificate authorities in advance and store them in the .ssh/authorized_keys directory of the client machines. The user wants to be sure that he or she has logged in to the machine that she is trying to log in to, especially if the authentication method is to send a password.   Otherwise, an attacker could act as a man-in-the-middle. Rule conflicts is a problem in a firewall rule set. Some rules are created for rejecting all the packets from a particular destination. On the other hand, some rules are established to accept all the packets from a particular destination. If reject and accept destination are same then rule conflicts will be Occur. In this case, some rule conflicts are present which is given bellow: Above table shows that rule 2 allow all the packets from the destination IP address and destination port. Rule 3 indicates that all the packets are rejected from a particular destination where the destination of rule 2 and 3 is same. Therefore, a rule conflict occurs. In this case rule, 13 allow all the packets those are using any protocol. But in rule 14 and 15 shows that the packets are rejected those are using TCP and UDP protocol. Therefore, a rule conflict occurs. The FIRST match policy put on the first rule which match the packet. The BEST match policy put on the rule which is more accurate regarding the network. The LAST match policy put on the rule that is first. Mainly it is bottom to top. Proxy Firewall is one type of network security system which protects a network by filtering the packets. This firewall is used in an application layer. The proxy firewall allows all the network traffic by checking their validity. Proxy firewall is placed in the network gateway.   All incoming packets are checked in the proxy server. If the packets are authorized then, proxy firewall grants the access. If not then proxy firewall destroy this packet.   The transparent firewall acts as a gateway of a network. Mainly it is a routed hop. It is also called layer 2 firewalls which perform as a "bump in the wire" or a "stealth firewall." A transparent firewall has commonly used the firewall. The proxy filter firewall is extremely secure than the transparent firewall. The main difference between the transparent firewall and proxy firewall is proxy firewall use a proxy server in the system, but the transparent firewall is used routed hop firewall. NAT stand for Network Address Translation. NAT is applied in a single device as a network gateway. For an example router. A net enables router connect with the internet and hide the entire private from the public network. In NAT system, it is not necessary to recognize all the internal devices. All the generated request by workstation are sent via the router. NAT help the router to transfer this packets in the internet t destination. The NAT convert the source address of all packets and place its IP address. If security is to provide in to the NAT, the network will be more secure for the attackers. Mainly NAT create a firewall for the security purpose. All servers that are presented to people in the general system (web), including web servers and DNS servers ought to be set in the DMZ. The DMZ is a different subnet situated outside of the association's system, but at the same time secured by a firewall. Movement starting from the organization's system is permitted into the DMZ, however, activity from the DMZ is not allowed into the association's system. This is imperative since ought to a server get to be bargained, and an aggressor cannot access the organization's inside system. Braun, J., Volk, F., Classen, J., Buchmann, J. and Mà ¼hlhà ¤user, M., 2014. CA trust management for the Web PKI. Journal of Computer Security, 22(6), pp.913-959. Bray, R.F., Grzelak, C.P. and Keirstead, J.D., International Business Machines Corporation, 2015. Firewall event reduction for rule use counting. U.S. Patent 9,043,461. Carthern, C., Wilson, W., Bedwell, R. and Rivera, N., 2015. Network Address Translation and Dynamic Host Configuration Protocol. In Cisco Networks (pp. 255-272). Apress. Francis, P., 2015. Network Address Translation (NAT). ACM SIGCOMM Computer Communication Review, 45(2), pp.50-50. Ghai, S. and Verma, A., 2015. Network Security Using Divergent Firewall Technologies. IITM Journal of Information Technology, 1, p.29. Kachare, M.S.S. and Deshmukh, P., 2015. Firewall Policy Anomaly Management with Optimizing Rule Order. International Journal of Application or Innovation in Engineering & Management (IJAIEM), 4(2), pp.201-205. Mao, H., Zhu, L. and Li, M., 2012, September. Current State and Future Development Trend of Firewall Technology. In Wireless Communications, Networking and Mobile Computing (WiCOM), 2012 8th International Conference on (pp. 1-4). IEEE. Vratonjic, N., Freudiger, J., Bindschaedler, V. and Hubaux, J.P., 2013. The inconvenient truth about web certificates. In Economics of information security and privacy iii (pp. 79-117). Springer New York.