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Table of Contents
Communication Network Security:.................................................................................................................................3

Introduction:................................................................................................................................................................... 3

Cryptographic security algorithm....................................................................................................................................4

How does Cryptographic security works.........................................................................................................................4

Systematic key Cryptography:.........................................................................................................................................4

Transposition Ciphers......................................................................................................................................................4

Asymmetric key encryption:............................................................................................................................................5

Substitution cipher:.........................................................................................................................................................5

Block Cipher technique:..................................................................................................................................................5

Hash Encryption:.............................................................................................................................................................6

Cryptography Features:...................................................................................................................................................6

Principles of public key cryptography in Network security:............................................................................................6

Important factors of Public key encryption:....................................................................................................................7

Public Key Encryption Schemes:......................................................................................................................................7

Public key and private concept of encryption:................................................................................................................7

RSA Encryption Method:.................................................................................................................................................8

RSA Analysis:................................................................................................................................................................... 8

EIGamal Cryptosystem....................................................................................................................................................9

EIGamal Analysis:............................................................................................................................................................9

Elliptic Curve Cryptography – ECC...................................................................................................................................9

Comparison of RSA and EIGamal schemes .....................................................................................................................9

Threats in Data Information:.........................................................................................................................................10

Passive Threat in Networks...........................................................................................................................................10

Active Threats in Networks...........................................................................................................................................10

Conclusion:....................................................................................................................................................................10

References – Harvard style............................................................................................................................................10

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ULO-3 Apply principles of public key cryptography to achieve secure communication using digital certificate and
digital signature in compliance with industry standards.

ULO-4 Justify the use of cryptographic scheme on networked infrastructures to prevent the misuse of technology.

Communication Network Security:

Introduction:
The cryptography is the type of science to protect the data by transforming in secure path. It is study of technology
for secure communication within the presence of third party called adversaries. It has two parts crypt means hidden
and graphy means writing. The cryptographic algorithm works on codes that are only understandable by the person
for whom it is being sent. It is important because it protects information from the unauthorized access and maintains
the confidentiality .It is used for the corporate sector to secure information. It hides all classified information of
company from the identity theft.

Cryptographic security
algorithm

It is on the basis of combination of methods known as Cipher .The cipher is commonly utilize in all computers
systems, phones to communicate the information in closed packet .In one packet delivery ,one cipher is used for
encryption ,second cipher for message authentication and third cipher of key exchange .The packet is known as
protocol ,coded in software.

How does Cryptographic security works.

There are few types of cryptographic security .It is new style of engineering method to protect data and
communication via the encrypted codes .It has two parts crypt means hidden and grapy means writing .

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Systematic key Cryptography:
In this system, the sender and receiver share the key which is mostly utilized for encrypt and decrypt he particular
information. So it is known as Data Encryption standard- DES.

Transposition Ciphers.

In this cipher method, plain text has been sent to receiver in regular system. Then it makes permutation of plain text.

Asymmetric key encryption:

It is also called public key .Here algorithm generates pair of keys for both sender and receiver to transfer
of private data.

Substitution cipher:
In this cipher method, the plain text has been sent in way but replaced with cipher text in the fixed system. The
information in terms of single letters, pair of letters, triple letters and mixture of letters.

Stream cipher:

In this cipher method, plaintext bit or bytes would be encrypted into different bits every time.

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Block Cipher technique:
This cipher method applies on symmetric key to crypt the block of pain text. It decodes all the block of information
rather than bits.

Hash Encryption:
In this method of encryption, the algorithm is no used in this technique. The operating systems have been using the
hash technology to encrypt password.

Cryptography Features:

 The privacy is very significant because only certified person only access the data and no other person
can access the information.
 The reliability of information is influential tool .The stored data can’t be tailored or edited between the
sender and receiver.
 The non-repudiation tool is used when creator and sender don’t deny the data at any stage.
 The validation tool is used to recognize the sender and receiver at each stages of destination.

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Principles of public key cryptography in Network security:
This type of algorithm depends on the one key for coding data and different keys for decoding the information. It
has important characteristics. It is computationally infeasible for decryption of data. This is new concept of
encryption of information. It is mostly used in the government, military and big financial companies who have
classified communication.

Important factors of Public key encryption:

In this method, there have different keys are utilized for encryption and decryption of information. It is available in
the symmetric encryption scheme. Each person who receives the unique decryption key known as private key and
receivers gets the information in encryption key known as public key. Surely there is assurance of authenticity must
be kept in this scheme. This cryptosystem must have trusted third party which gives the certificate that a public is
devoted to specific person. No doubt, it is complex method of algorithm but it prohibits attackers to lookout he
actual information. The public and private keys both works on mathematically. It is not possible to calculate the
public key from the private key.

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Public Key Encryption Schemes:

Public key and private concept of encryption:

There have been different keys are used for coding and decoding the information. On is public key from the sender
and other is private key which is only known by the receiver.

There are about three public key encryption schemes.

RSA Encryption Method:

This type of technique for encryption has been using widely known as public key encryption. The Rivest , Shamir and
Adelman had invented RSA technique of encryption. In this method both public and private keys are used. The
variable key sizes are 512, 1024 and 2048 bits

The RSA cryptosystem is belongs to initial systems. It is now commonly used in the networks. In this technique each
person who wants to participate in communication so they need to generate the pair of keys called the public key
and private key. The RSA modulus is designed as select p and q and then calculate n = p x q. It is unbreakable
encryption of information. Then find the derived number from the equation. P-1 and q -1. So there is no common
factor in this equation. And form the public key. The pair of numbers n and e prepares the RSA public key. So the
attacker can’t find the finite time and decode the data. And now prepare the private key in way that calculated from
p, q and e. and number d is inverse of modulus.

ed = 1 mod (p − 1)(q − 1)

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The RSA doesn’t operate on strings. It works on number modulo.

RSA Analysis:
In the RSA system security depends on the two functions. It is strong popular public key in the network systems. It is
mostly considered as one type function for converting the plaintext into cipher text. It is also reversed to private key
d. It is very difficult to determine the private key in the RSA system. The attacker can’t identify the information and
decode it according to its will.

EIGamal Cryptosystem.
This technique is different than RSA crypto system. It is known as Elliptic curve variant in the network system. It is
based on discrete logarithm problems. It can’t be identified in practical time frame but inverse operation can be
computed. It works on the number modulo p. In these systems, each user can generate pair of keys. The prime
number p of 1024 and 2048 bits must be chosen in length. The number can be 1 and p-1. It is also generator of
multiplicative group integers of modulo p.

y = gx mod p

The private key x is bigger than one. The EIGamal public key has three parameters such as p, g and y. The key pair
generation is simple in this method but encryption and decryption is more complex than RSA.

EIGamal Analysis:
However, in this data transfer system each user has private key x but it involves in three factors such as prime
modulus p, generator g and public y . The strength of EIGamal systems is depends upon the difficult algorithm
system. It has 1024 is secure key size. But now a day’s 2048 has been widely used.

Elliptic Curve Cryptography – ECC

The ECC systems are combination of cryptographic tools and protocols. Its security depends on the complex discrete
algorithm problems. It doesn’t work on modulo p. The ECC systems works on the sets of numbers. All sets are
combined with mathematical objects so it is known as elliptic curves. In this systems few rules have been defines for
adding and computing multiples of numbers. The ECC has many cryptographic schemes. It is basically designed for
modulus numbers such EIGamal and digital signature algorithm. It is much harder than the previous systems. It
has shorter key benefits such as ease of key management of information and light computation.

Comparison of RSA and EIGamal schemes .

RSA EIGamal
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 Easy encryption Easy decryption
Less easy decryption Easy decryption
It has strong security level It needs simple security
It needs lengthy keys It needs shorter keys.

Threats in Data Information:

Meanwhile, in big financial corporations when confidential data is being transferred, the receiver’s user must have
surety of information from the sender in shape of digital signature. We have two types of threats from the attacker.

Passive Threat in Networks.

The data errors have been caused in the networks due to noise in communication channel. The sent information
would be corrupt when the file is stored in the database. In passive threats error correcting codes and checksums
has been used for detecting the main error such as cyclic redundancy checks. In this method the data is being
digested mathematically.

Active Threats in Networks.

The active threats have been caused due to accidental changes in information. If the data is sent without digest. It
can be modified without detection in simple level of threats. In high level of threats, the information can be modified
by the attackers. They try to modify the new digest rather than the existing digest of information. For the security
purpose Hash functions are utilized to overcome the active modification threats.

Conclusion:

They cryptographic security systems works as transporting system which has done encoding and decoding of data
from one place to another place. It has few other services such as hashing, random no generation, and message
authentication. It uses mathematical equations or algorithm for encrypt and decrypt data

The technology which is widely used in computer systems. The crypto security is the mixture of hardware and
software security keys also called encryption keys or encryption variables. It pedals the computer paths to enter the
data. The cryptographic uses cipher text which protects information from transferring into readable from. Only one
person who have key to open it or decrypt it to read the information. It protects emails, Banks credit cards and
company’s data from hackers.

References – Harvard style.

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Shashank (2018). What is Cryptography? – An Introduction to Cryptographic Algorithms. [online] Edureka. Available
at: https://www.edureka.co/blog/what-is-cryptography/.
In-text citation: (Shashank, 2018)

admin (2020). A Glossary of Cryptographic Algorithms. [online] GlobalSign GMO Internet, Inc. Available at:
https://www.globalsign.com/en/blog/glossary-of-cryptographic-algorithms [Accessed 29 Jul. 2020].
In-text citation: (admin, 2020)

Bradford, C. (2016). 5 Common Encryption Algorithms and the Unbreakables of the Future. [online] StorageCraft
Technology Corporation. Available at: https://blog.storagecraft.com/5-common-encryption-algorithms/.
In-text citation: (Bradford, 2016)

sectigo.com. (n.d.). Sectigo. [online] Available at: https://sectigo.com/public-key-vs-private-key.

In-text citation: (sectigo.com, n.d.)

PreVeil. (n.d.). What are public and private key pairs and how do they work. [online] Available at:
https://www.preveil.com/blog/public-and-private-key/.
In-text citation: (PreVeil, n.d.)

Khan Academy. (n.d.). Public key encryption (article). [online] Available at:
https://www.khanacademy.org/computing/computers-and-the-internet/xcae6f4a7ff015e7d:online-data-security/
xcae6f4a7ff015e7d:data-encryption-techniques/a/public-key-encryption [Accessed 29 Jul. 2020].
In-text citation: (Khan Academy, n.d.)

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