CRYPTOGRAPHY AND NETWORK SECURITY

1. VIDYAVAHINIFIRSTGRADECOLLEGE
VIDYAVAHINI GROUPOFINSTITUTIONS
AFFILIATEDTO TUMKURUNIVERSITY • KUVEMPUNAGAR/SIT EXTENTION, TUMKUR572103

2. OVERVIEW
1. Introduction
2. Types of Cryptographic
Attacks

3. 1.INTRODUCTION
Definition:
• An attack is gaining the access of data by Unauthorized
person.
• It is also called as Security Attacks and Security threats
• Here gaining means
 Accessing / Reading /Viewing/ Listening the data
 Modifying the data
 Destroying the data

4. 2.TYPES OF ATTACKS
Attacks are classified into two types

5. I. PASSIVE ATTACK
Passive Attacks are the type of attacks in which,
the attacker observes the content of message
or copy the content of messages.
• Passive Attack is danger for Confidentiality.
• Due to passive attack, there is no any harm to
the system and its Resources.
• In this type of attacks data will not be
modified, just the data will be accessed by the
third person means unauthorized person.
• In this victim (receiver or sender) does not get
information about the attack.

6.  Passive Attack has Two Techniques
i. Release of Message Content.
When sender sends a message to receiver, during
transmitting data unauthorized person can get the data,
they can listen or read the messages but not modified.

7. ii. Traffic Analysis
Here sender sends a message to receiver, in between
that third party can monitoring pattern of those
messages and observes traffic or data flow and
length of the messages then they can easily access the
data but not modified.

8. II. ACTIVE ATTACK
Active attacks are the type of attacks in which,
the attacker or unauthorized person To change
or modify the content of messages.
Active Attack is danger for Integrity as well as
availability.
Due to active attack system is always
damaged and System resources can be
changed.
The most important thing is that, in active
attack, Victim (sender and receiver) gets
information about the attack.

9. Active Attack has Four Techniques
i. Masquerade
• Here sender does not send any data
to the receiver but receiver will
receives the data from the third party
with the name of sender.
• Here data will be modified; receiver
does not know who sent the message.
• Here receiver does not receive
message by sender but with the name
of sender.

10. ii. Replay Attack
• Here if sender sends data to receiver,
while at the time of transferring of data
the same data will be gained by third
party and the same message will be
sent again to the receiver.
• Now receiver will receive same
message twice, first time from sender
and another time from third party.
• Here the problem is, receiver does not
know who is valid sender is and which
message from original source.

11. iii. Data Modification
• Here also sender sends the data to
receiver but it does not go to the
receiver directly, that message is
directly accessed by the 3rd party and
data will be modified and that modified
data will be received by the receiver.
• The receiver does not know there is a
data modification done.

12. iv.Denial of Services (DOS)
• Always server provides services to
sender and then sender provide them
to receiver.
• But in between that unauthorized
person disrupts or interrupts or
destroy the services sends by the
server to sender on the name of
sender.