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Security On The Web Essay, Research Paper
How do you secure something that is changing
faster than you can fix it? The Internet has had security problems since
it?s earliest days as a pure research project. Today, after several years
and orders of magnitude of growth, it still has security problems. The
Internet is being used for a purpose for which it had never intended to
be used for. It is somewhat ironic that the early Internet was design as
a prototype for a high-availability command and control network that could
resist outages resulting from an enemy attack, yet it cannot resist college
undergraduates. The problem is that the attackers are on, and make up apart
of, the network they are attacking. Designing a system that is capable
of resisting attack from within, while still growing and evolving at a
rapid pace, is probably impossible. Deep infrastructure changes are needed,
and once you have achieved a certain amount of size, the sheer inertia
of the installed base may make it impossible to apply fixes.
The challenge for the security industry
is growing. With the electronic commerce spreading over the Internet, there
are new issues being developed everyday such as non-repudiation that will
need to be solved. Financial institutions will have both technical concerns,
such as the security of a credit card number or banking information, and
legal concerns for holding individuals responsible for their actions such
as their purchases or sales over the Internet. Issuance and management
of encryption keys for millions of users will pose a new type of challenge.
While some technologies have been developed,
only an industry-wide effort and cooperation can minimize risks and ensure
privacy for users, data confidentiality for the financial institutions,
and non-repudiation for electronic commerce.
With the continuing growth in linking
individuals and businesses over the Internet, some social issues are starting
to surface. The society may take time in adapting to the new concept of
transacting business over the Internet. Consumers may take time to trust
the network and accept it as a substitute for transacting business in person.
Another class of concerns relates to restricting access over the Internet.
Preventing distribution of pornography and other objectionable material
over the Internet has already been in the news. We can expect new social
hurdles over time and hope the great benefits of the Internet will continue
to override these hurdles through new technologies and legislations.
The World Wide Web is the single largest,
most ubiquitous source of information in the world, and it sprang up spontaneously.
People use interactive Web pages to obtain stock quotes, receive tax information
from the Internal Revenue Service, check the local weather, consult a pregnancy
planner to determine ovulation dates, conduct election polls, register
for a conference, search for old friends, and the list goes on. It is only
natural that the Web?s functionality, popularity, and ubiquity have made
it the seemingly ideal platform for conducting electronic commerce. People
can now go online to buy CDs, clothing, concert tickets, and stocks. Several
companies, such as Digicash, Cybercash, CarParts.com, and First Virtual,
have sprung up to provide mechanisms for conducting business on the Web.
The savings in cost and the convenience of shopping via the Web are immeasurable.
Where as most successful computer systems resulted from careful, methodical
planning, followed by hard work, the Web took on a life of its own from
the very beginning. The introduction of a common protocol and a friendly
graphical user interface was all that was needed to ignite the Internet
explosion. The Web?s virtues are extolled without end, but its rapid growth
and universal adoption have not been without cost. In particular, security
was added as an afterthought.
New capabilities were added to satisfy
the growing demand for features without carefully considering the impact
on security. As a general-purpose, scripts were introduced on both the
client and the server sides of the Web. It did not take long for the Web
to move from the scientific community to the commercial world. For then
the dangers of accidental and malicious abuse grew. At this point, the
security threats became much more serious. The incentive for malicious
attackers to exploit vulnerabilities in the underlying technologies is
at an all-time high. This is indeed frightening when we consider what attackers
of computer systems have accomplished when their only incentive was fun
and personal enjoyment while boosting their egos. When business and profit
are at stake, we cannot assume anything less than the most dedicated and
resourceful attackers typing their utmost will and determination to steal,
cheat, and perform mischievous attacks against their pray (users of the
When people use their computers to surf
the Web, they have many expectations. They expect to find all sorts of
interesting information, they expect to have opportunities to shop and
they expect to be bombarded with all sorts of ads. Even people who do not
use the Web are in jeopardy of being intimidated by the Web. So when it
comes down to the significant importance of Web security it affects us
There are simple and advanced methods for
ensuring browser security and protecting user privacy. The more simple
techniques are user certification schemes, which rely on digital IDs. Netscape
Communicator and Internet Explorer allow users to obtain and use personal
certificates. Currently, a certification company called Verisign offers
digital Ids that consist of a certificate of a user?s identity. The Digital
IDs are divided into different types of classes of digital Ids, each represents
a different level of assurance in the identity, and each comes at an increasingly
higher cost. The assurance is determined by the effort that goes into identifying
the person requesting the certificate.
Class 1 Digital IDs intended for casual
Web browsing providing users with an unambiguous name and e-mail address
within Verisign?s domain. A Class 1 ID provides assurance to the server
that the client is using an identity issued by Verisign but with little
guarantee about the actual person behind the ID.
Class 2 Digital IDs require third party
confirmation of name, address, and other personal information related to
the user, and they are available only to residents of the United States
and Canada. The information provided to Verisign is checked against a consumer
database maintained by Equifax. To protect against insiders at Verisign
issuing bogus Digital IDs, a hardware device is used to generate the certificates.
Class 3 Digital IDs are not available.
The purpose is to bind an individual to an organization. Thus, a user in
possession of such an ID, theoretically, could prove that he or she belongs
to the organization that employs him or her.
The idea behind Digital IDs is that they
are entered into the browser and then are automatically sent when users
connect to sites requiring personal certificates. Unfortunately, the only
practical effect is to make impersonating users on the network only a little
bit more difficult.
Many Web sites require their users to register
a name and a password. When users connect to these sites, their browser
pops up an authentication window that asks for these two items. Usually,
the browser then sends the name and password to the server allowing retrieval
of the remaining pages at the site. The authentication information can
be protected from eavesdropping and replay by using the SSL protocol.
As the number of sites requiring simple
authentication grows, so does the number of passwords that each user must
maintain. In fact, users are often required to have several different passwords
for systems in their workplace, for personal accounts, for special accounts
relating to payroll and vacation, and so on. It is not uncommon for users
to have more than six sites they visit that require passwords.
In the early days of networking, firewalls
were intended less as security devices than as a means of preventing broken
networking software or hardware from crashing wide-area networks. In those
days, malformed packets or bogus routes frequently crashed systems and
disrupted servers. Desperate network managers installed screening systems
to reduce the damage that could happen if a subnet?s routing tables got
confused or if a system?s Ethernet card malfunctioned. When companies began
connecting to what is now the Internet, firewalls acted as a means of isolating
networks to provide security as well as enforce, otherwise known as an
administrative boundary. Early hackers were not very sophisticated; neither
were early firewalls.
Today, firewalls are sold by many vendors
and protect tens of thousands of sites. The products are a far cry from
the first-generation firewalls, now including fancy graphical user interfaces,
intrusion detection systems, and various forms of tamper-proof software.
To operate, a firewall sits between the protected network and all external
access points. To work effectively, firewalls have to guard all access
points into the network?s perimeter; otherwise an attacker can simply go
around the firewall and attack an undefended connection.
The simple days of the firewalls ended
when the Web exploded. Suddenly, instead of handling only a few simple
services, firewalls now must be connected with complex data and protocols.
Today?s firewalls have to handle multimedia traffic, attached downloadable
programs (applets) and a host of other protocols plugged into Web browsers.
This development has produced a basis conflict, the firewall is in the
way of the things users want to do. A second problem has arisen as many
sites want to host Web servers: Does the Web server go inside or outside
of the firewall? Firewalls are both a blessing and a curse. Presumably,
they help deflect attacks; but they also complicate users? lives, make
a Web Server Administration job a bit harder, rob network performance,
add an extra point of failure, cost money, and make networks more complex
Firewall technologies, like all other
Internet technologies, are rapidly changing. There are two main types of
firewalls, plus many variations. The main types of firewalls are proxy
and network-layer. The idea of a proxy firewall is simple: Rather than
have users log into a gateway host and then access the Internet from there,
give them a set of restricted programs running on the gateway host and
let them talk to those programs, which act as proxies on behalf of the
user. The user never has an account or the need to login on the firewall
itself, and he or she can interact only with a tightly controlled restricted
environment created by the firewall?s administrator.
This approach greatly enhances the security
of the firewall itself because it means that users do not have accounts
or shell access to the operating system. Most UNIX bugs require that the
attacker have a login on the system to exploit them. By throwing the users
off the firewall, it becomes just a dedicated platform that does nothing
except support a small set of proxies, it is no longer a general-purpose
computing environment. The proxies, in turn, are carefully designed to
be reliable and secure because they are the only real point of the system
against which an attack can be launched.
Proxy firewalls have evolved to the point
where today they support a wide range of services andrun on a number of
different UNIX and Windows platforms. Many security experts believe that
proxy firewalls are more secure than other types of firewalls, largely
because the first proxy firewalls were able to apply additional control
on to the data traversing the proxy. The real reason for proxy firewalls
was their ease of implementation, not their security properties. For security,
it does not really matter where in the processing of data the security
check is made; what?s more important is that it is made at all. Because
they do not allow any direct communication between the protected network
and outside world, proxy firewalls inherently provide network address translation.
Whenever an outside site gets a connection from the firewall?s proxy address,
it in turn hides and translates the addresses of systems behind the firewall.
Prior to the invention of firewalls, routers
were often pressed into service to provide security and network isolation.
Many sites connecting to the Internet in the early days relied on ordinary
routers to filter the types of traffic allowed into or out of the network.
Routers operate on each packet as an unique event unrelated to previous
packets, filtered on IP source, IP destination, IP port number, and other
basic data contained in the packet header. Filtering does not constitute
of a firewall because it does not have quite enough detailed control over
data flow to permit building highly secure connections. The biggest problem
with using filtering routers for security is the FTP protocol, which, as
part of its specification, makes a callback connection in which the remote
system initiates a connection to the client, over which data is transmitted.
Cryptography is at the heart of computer
and network security. The important cryptographic functions are encryption,
decryption, one-way hashing, and digital signatures. Ciphers are divided
into two categories, symmetric and asymmetric, or public-key systems. Symmetric
ciphers are functions where the same key is used for encryption and decryption.
Public-key systems can be used for encryption, but they are also useful
for key agreement and digital signatures. Key-agreement protocols enable
two parties to compute a secret key, even in the face of an eavesdropper.
Symmetric ciphers are the most efficient
way to encrypt data so that its confidentiality and integrity are preserved.
That is, the data remains secret to those who do not posses the secret
key, and modifications to the cipher text can be detected during decryption.
Two of the most popular symmetric ciphers are the Data Encryption Standard
(DES) and the International Data Encryption Algorithm (IDEA). The DES algorithm
operates on blocks of 64 bits at a time using a key length of 56 bits.
The 64 bits are permuted according to the value of the key, and so the
encryption with two keys that differ in one bit produce two completely
different cipher texts. The most popular mode of DES is called Cipher Block
Chaining (CBC) mode, where output from previous block are mixed with the
plaintext of each block. The first block is mixed with the plaintext of
each block. The block uses a special value called the Initialization Vector.
In conclusion, despite its size and rapid
growth, the Web is still in its infancy as with the software industry.
We are just beginning to learn how to develop secure software, and we are
beginning to understand that for our future, if it is to be online, we
need to incorporate security into the basic underpinnings of everything
we develop. Today, no one method of Internet Security can stop a hacker
from intruding on our privacy. The goal is that as time goes on and we
increase our technological knowledge of the Internet, that we raise our
standards of security in everything we do weather on our computers or on
the Internet; Thus we will hopefully be more protected by what we enjoy
so much, the Internet.
Digital Evidence and Computer Crime: Forensic
Science, Computers and the Internet
January 2000, by Eoghan Casey
Cybershock: Surviving Hackers, Phreakers,
Identity Thieves, Internet Terrorists and Weapons of Mass Disruption
April 2000, by Winn Schwartau
Liberating Cyberspace: Civil Liberties,
Human Rights and the Internet
May 1998 by Libertty
Firewalls a Complete Guide: A look into
the vulnerability of a typical Internet-connected network and shows how
various kinds of firewalls can reduce the threat from outside.
Nov. 1999, by Marcus Goncalves
SunWorld: The human side of computer security
July 1999 http://www.idg.net/crd_idgsearch_77790.html?sc=40050501_139910
PcWorld.com: Privacy Special Report: Stealth
Surfing May 2000
Digital Ids: a report on server and client
certificates that aren’t yet widely used for authentication.
March 1997 Byte.com
Verisign Inc: ?Verisign Inc is the leading
provider of Internet trust services needed by Web sites, enterprises, and
e-commerce service providers to conduct trusted and secure electronic commerce
and communications over IP networks.? http://www.verisign.com
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