Internet security

Description
It talks about the vulnerabilities in the systems and kinds of internet threats like firewall intrusion, DoS, Hijacking, virus etc.

Internet Security

• A network of networks • A logic network composed of a set of autonomous sub networks connected by gateways • Open architecture • Different protocols for physical transmission • A single protocol suite for the network and transport layers

? Dictionary.com
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says:

1. Freedom from risk or danger; safety. ? 2. Freedom from doubt, anxiety, or fear; confidence. ? 3. Something that gives or assures safety, as:
? ?

?

1. A group or department of private guards: Call building security if a visitor acts suspicious. 2. Measures adopted by a government to prevent espionage, sabotage, or attack. 3. Measures adopted, as by a business or homeowner, to prevent a crime such as burglary or assault: Security was lax at the firm's smaller plant.

…etc.
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? Protect
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vital information while still allowing access to those who need it
Trade secrets, medical records, etc.

? Provide
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authentication and access control for resources
Ex: AFS

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? Financial

institutions and banks ? Internet service providers ? Pharmaceutical companies ? Government and defense agencies ? Contractors to various government agencies ? Multinational corporations ? ANYONE ON THE NETWORK

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?
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Finding a way into the network
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Firewalls Intrusion Detection Systems Ingress filtering, IDS IPSec Encryption (SSH, SSL, HTTPS) Education
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Exploiting software bugs, buffer overflows
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Denial of Service
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TCP hijacking
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Packet sniffing
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Social problems
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High Sophistication of Hacker Tools

Technical Knowledge Required Low

1980

1990

2000

-from Cisco Systems

The Need for Web Security

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HACKED WWW HOMEPAGES

CIA HOMEPAGE

DOJ HOMEPAGE

USAF
The Need for Web Security

HOMEPAGE
11/29/96

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? ? ? ? ? ? ?

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Money, profit Access to additional resources Experimentation and desire to learn “Gang” mentality Psychological needs Self-gratification Personal vengeance Emotional issues Desire to embarrass the target
The Need for Web Security

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?A
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firewall is like a castle with a drawbridge
Only one point of access into the network This can be good or bad

? Can
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be hardware or software

Ex. Some routers come with firewall functionality ipfw, ipchains, pf on Unix systems, Windows XP and Mac OS X have built in firewalls

15-441 Networks Fall 2002

10

Internet

DMZ
Web server, email server, web proxy, etc
Firewall Firewall

Intranet

15-441 Networks Fall 2002

11

? Basic

problem – many network applications and protocols have security problems that are fixed over time
? ?

Difficult for users to keep up with changes and keep host secure Solution
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Administrators limit access to end hosts by using a firewall Firewall is kept up-to-date by administrators

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? Used
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to monitor for “suspicious activity” on a network
Can protect against known software exploits, like buffer overflows

15-441 Networks Fall 2002

13

Spam
?Spam is the e-mail equivalent of the junk mail (pamphlets, menus, shopping flyers) that fill your non-Internet mailbox every day. ?Spam is simply any piece of unsolicited e-mail: it may be sent to just you, or it may be sent to a million others--either way it's spam if you didn't ask for it. ?The term "spam" originated, as do many geeky concepts, from a Monty Python skit[www.detritus.org/spam/skit.html]. ?Lists of 100,000s or even millions of e-mail addresses are available for purchase which can then be used to send out that many spam messages in a few minutes. Even if only a minute fraction of people respond, spam is still the most cost-efficient marketing method in existence.

? The

Internet works only because we implicitly trust one another ? It is very easy to exploit this trust ? The same holds true for software ? It is important to stay on top of the latest CERT security advisories to know how to patch any security holes

15-441 Networks Fall 2002

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doc_562248101.pptx
 

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