A computer virus is a self-replicating program containing code that explicitly
copies itself and that can "infect" other programs by modifying them
or their environment such that a call to an infected program implies a call to
a possibly evolved copy of the virus.
software "pranks" are very serious; they are spreading faster than they
are being stopped, and even the least harmful of viruses could be life-threatening.
For example, in the context of a hospital life-support system, a virus that "simply"
stops a computer and displays a message until a key is pressed, could be fatal.
Further, those who create viruses can not halt their spread, even if they wanted
to. It requires a concerted effort from computer users to be "virus-aware",
rather than continuing the ambivalence that has allowed computer viruses to become
such a problem.
Computer viruses are actually
a special case of something known as "malicious logic" or "malware".
the set of programs which produce one or more programs as output. For any pair
of programs p and q, p eventually produces q if and only if p produces q either
directly or through a series of steps (the "eventually produces" relation
is the transitive closure of the "produces" relation.) A viral set is
a maximal set of programs V such that for every pair of programs p and q in V,
p eventually produces q, and q eventually produces p. ("Maximal" here
means that there is no program r not in the set that could be added to the set
and have the set still satisfy the conditions.)
For the purposes of this paper,
a computer virus is a viral set; a program p is said to be an instance of, or
to be infected with, a virus V precisely when p is a member of the viral set V.
A program is said to be infected simpliciter when there is some viral set V of
which it is a member. A program which is an instance of some virus is said to
spread whenever it produces another instance of that virus. The simplest virus
is a viral set that contains exactly one program, where that program simply produces
itself. Larger sets represent polymorphic viruses, which have a number of different
possible forms, all of which eventually produce all the others.
You may also like this : 4G Broadband seminar report, Finger Tracking In Real Time Human Computer Interaction, Eye Movement-Based Human Computer Interaction Techniques, Ethical Hacking, E-Cash Payment System PPT, Cyborgs, Brain Fingerprinting Biometrics in SECURE e-transaction, X- Internet, Surface Computer, Secure ATM by Image Processing, Mobile Ad-Hoc Networks Extensions to Zone Routing Protocol, Wibree PDF , Telepresence, System in Package, Smart Memories, Slammer Worm, Sensitive Skin, Pixie Dust, Linux Kernel 2.6, Lamp Technology, Humanoid Robot, HTAM, Haptic Technology, Elastic Cluster, Digital Scent Technology, Distributed Interactive Virtual Environment, Dynamic TCP Connection Elapsing, CAPTCHA, Virtual Retinal Display, Wireless LAN Security, Chameleon Chip, Haptics, Intelligent RAM, iSCSI, Linux Kernel 2.6, 3D Searching, Biological Computers, Rain Technology, Real Time Application Interface, GPS, HALO , BitTorrent, Compositional Adaptation, Rover Technology,Computer Seminars