  Phishing is a common online weapon, used against users, by Phishers for
acquiring a confidential information through deception. Since the inception of
internet, nearly everything, ranging from money transaction to sharing
information, is done online in most parts of the world. This has also given
rise to malicious activities such as Phishing. Detecting Phishing is an
intricate process due to complexity, ambiguity and copious amount of
possibilities of factors responsible for phishing . Rough sets can be a
powerful tool, when working on such kind of Applications containing vague or
imprecise data. This paper proposes an approach towards Phishing Detection
Using Rough Set Theory. The Thirteen basic factors, directly responsible
towards Phishing, are grouped into four Strata. Reliability Factor is
determined on the basis of the outcome of these strata, using Rough Set Theory
. Reliability Factor determines the possibility of a suspected site to be Valid
or Fake. Using Rough set Theory most and the least influential factors towards
Phishing are also determined.
