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Cryptography and
Network Security
Presented by
1. Shubhangi Gosake (21121)
2. Sanskruti Gosake (21219)
3. Nutan Waghmode (21268)
4. Supriya Koli (21160)
5. Bhavana Sonawane (21159)
Table of Content
1. What is security?
2. Attacks
1.Active attack
2.Passive attack
3.What is cryptography?
What is Security?
 Network security is a broad term that covers a multitude of
technologies, devices and processes.
 It refers to a set of rules and configurations designed to protect the
integrity, confidentiality, and accessibility of computer networks and
 Network security is any activity designed to protect the usability and
integrity of your network and data.
• It includes both hardware and software technologies
• It targets a variety of threats]
• It stops them from entering or spreading on your network
• Effective network security manages access to the network
Active attacks
 Active attacks are the type of attacks in which, The attacker
efforts 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 gets
informed about the attack.
Passive Attack
 Passive Attacks are the type of attacks in which, The attacker
observes the content of messages or copy the content of
 Passive Attack is danger for Confidentiality.
 Due to passive attack, there is no any harm to the system.
 The most important thing is that In passive attack, Victim does
not get informed about the attack.
What is cryptography ?
 Cryptography derived its name from a Greek word called “krypto’s” which
means “Hidden Secrets”.
 Cryptography is the practice and study of hiding information.
 It is the Art or Science of converting a plain intelligible data into an
unintelligible data and again retransforming that message into its original
 It provides Confidentiality, Integrity, and Accuracy.
• Plain Text: The message which we send to the receiver. For e.g.- “Hello”
• Cipher Text: Conversion of that plain text into a non-readable format. For e.g.“H@#$5”
Asymmetric Cryptography
 Under this system , a pair of keys is used to encrypt and decrypt
 A public key is used for encryption and a private key is used for
 Public key and Private Key are different, even if the public key is
known by everyone the intended receiver can only decode it
because he alone knows the private key.
 The public key is available to the public, and the private key is
available only to an individual.
Symmetric key Cryptography
 It is an encryption system where the sender and receiver of
message use a single common key to encrypt and decrypt
 Symmetric Key Systems are faster and simpler but the problem is
that sender and receiver have to somehow exchange key in a
secure manner.
 The most popular symmetric key cryptography system is Data
Encryption System(DES).
 A firewall is a network security system that manages and regulates the
network traffic based on some protocols. A firewall establishes a barrier
between a trusted internal network and the internet.
 Firewalls are commonly used in private networks or intranets to prevent
unauthorized access from the internet.
 Firewalls exist both as software that run on a hardware and as hardware
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