Types of Computer Attacks

Attacks in a computer network can be classified into two types. These are :

(a) Passive Attack
(b) Active Attack

Passive Aattack ::

Eavesdropping on or monitoring of transmissions is known as 'passive attack'. The goal of eavesdropping is to obtain that information which is being transmitted. Passive attacks are difficult to detect (if they occur) but they can be prevented.

Active Attack ::

Modification of message being transmitted, capturing authentication sequences and obtaining extra privileges, creation of false message etc. are a few active attacks. Active attacks are difficult to prevent because they require protection of all communication facilities and paths at all times. But one can detect and recover from the disruptions caused by them.

Some commonly known network threats are :

(a) Identity Interception : The identity of one or more of the users involved in a communication is observed for misuse.

(b) Pretending : The pretence by a user to be a different user in order to gain access to information or to acquire additional privileges.

(c) Replay : The recording and subsequent replay of a communication at some later date.

(d) Data Interception : The observation of user data during a cummunication by an unauthorized user.

(e) Manipulation : The replacement, insertion, deletion or disordering of user data during a communication by an unauthorized user.

(f) Rejection : The denial by a user of having participated in part of all of a communication.

(g) Denial of service : The prevention or interruption of a communication or the delay of timecritical operation.

(h) Mis-routing : The mis-routing of a communication path intended for onr user to another.

(i) Traffic Analysis : The obeservation of information about a communication between user (absence/presence, frequency, direction, sequence etc.)