Security of Internet Protocol
The IP protocol suite, including TCP/IP, was designed to
provide reliable and scalable communications over real-world networks.
It has served this goal well. However, it was designed twenty years ago
in a world where the Internet consisted of a few hundred
closely controlled hosts. The situation has changed. The
Internet now connects tens of millions of computers,
controlled by millions of individuals and organizations. The core
network itself is administered by thousands of competing operators, and
the network spans the whole globe, connected by fibers, leased lines,
dialup modems, and mobile phones.
The phenomenal growth of the Internet has peaked the interest of
businesses, military organizations, governments, and criminals.
Suddenly, networks are changing the way business is done. They have
changed the nature of trade and distribution networks, and the way
individual people communicate with each other.
This upsurge of business communications, scientific communications and political
communications on the Internet has also brought out negative elements. Criminals
are looking for ways of getting a cut of the emerging business. Industrial
espionage has become a reality. Intelligence agencies are showing growing
interest towards networked communications, and they often exchange information
with domestic commercial interest and political groups. Crackers, exchanging
information and source code, make attacks that ten years ago were thought to be
only within the reach of superpowers' intelligence agencies.
Consequently, the IP protocol, while very tolerant of random errors, is
vulnerable to malicious attacks. The most common types of attacks include:
- Eavesdropping on a transmission, for example,
looking for passwords, credit card numbers, or business secrets.
- Hijacking, or taking over a
communication in such a way that the attacker can inspect and modify any data
being transmitted between the communicating parties.
- IP spoofing,
or faking network addresses or host names in order to fool
access control mechanisms based on them or to redirect connections to a fake
server.
The SSH2 protocol is designed to protect network communications against security
hazards like these.
