AES1210 Unit 3 Assignment 1

AES1210 Unit 3 Assignment 1
We can say that the weakness of the keys and the process of incorrect use, as well as erroneous implementation
cannot be considered as a unique case because it represents a common risk for each encryption algorithms [21].
1. The AES Algorithm (AES) is a coherent block cipher and this block with size 128 bits. The key length be 128
bits,192 bits , or 256 bits and take the following nomenclature; AES–128, AES–192, and AES–256 . AES128
uses 10 rounds, AES–192 uses 12 rounds, and AES–256 uses 14 rounds [22].
The main loop of the algorithm that performs the following tasks:–
a. Sub Bytes ().
b. Shift Rows ().
c. Mix Columns ().
d. Add Round Key (). The first three functions of this algorithm have been designed
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Protocols Of Encryption And Encryption
INDEX
1. Objective
2. Introduction
3. Encryption
a. Asymmetric Encryption
b. Symmetric Encryption
4. Examples of encryption
5. Cryptography
6. Email Encryption
a. Advantages of Encryption Email
b. Disadvantages of Encryption Email
c. Why use the Encryption Email
7. Use of Encryption
8. How it works
9. Protocols of the Email Encryption
a. PGP
b. S/MIME
c. Message Encryption
d. Mail session Encryption
e. TLS
10. Conclusion
11. References
Objective
Email Encryption is the very important topic of todays need. Because it provides the proper security to the
message. And in now days everybody wants the proper security for our message so that the original message as it
is read by the recipient that are send by the sender without any changes/alternation in the message. So this is the
very important topic to cover up and secure our messages from unauthorized user's access. That provide the
security to our communication. So, we can easily communicate without any afraid of hacking of data.
INTRODUCTION:– Encryption is the most effective way to provide the data security. It is a process which
converts original information into a difficult–to–interpret form. The original information is known as plain text
and the converted information/message is commonly known as cipher text.
In now a days you email delicate, individual and business data to your recipients, then encryption is likely a
need. But still 99% of all emails movement goes

Attacks On Gsm Standards : Attack Against Mobile...
Attacks on GSM Standards: Attacks against mobile communication are not only depends on the network
weaknesses but the reasons may be mobile phones malware, identity theft by SIM cloning and so on. Some other
attacks, such as phishing with SMS, may exploit human factors as well. But most of these attacks are done on the
A5 family of ciphering algorithms. The exact formulation of these algorithm is still unknown but many
researchers try to calculate it through reverse engineering and cryptanalysis. Some of the attacks done on A5 are
discuss below, that can be distinguished as passive and active attacks. PASSIVE ATTACKS: After the general
configuration of A5/1 was released, a few shortcomings of this calculation have Been uncovered by mainstream
researchers. The primary assault focusing on the A5/1 calculation has been proposed by Golic [Golic 1997],
which presented a successful Time–Memory Trade–Off (TMTO) assault in light of the birthday Catch 22. This
method is pertinent to any cryptosystem with a generally little number of inner states like A5/1, which has 264
states characterized by three movement registers. The essential thought of the TMTO is to pre–process a huge set
of states A, and to consider the arrangement of states B through which the calculation advances amid the era of
yield bits. Any crossing point in the middle of A and B permits the distinguishing proof of a genuine condition of
the calculation. The proposed assault would be practicable just having

CSEC 630 Lab Assignment 1 Introduction To Cryptography Essay
Lab Assignment 1 – Introduction to Cryptography
Laurel Schneider
CSEC 630 – Prevention and Protection Strategies in Cybersecurity
University of Maryland University College
Jeffrey Daniels
February 21, 2015
Q1. Which tool or technique from the above list would be most effective for a cryptanalyst to use to decipher a
text encrypted with the Caesar cipher, and why?
The Caesar cipher is a substitution cipher that substitutes one character for another and shifting the alphabet by a
determined number of spaces. This type of cipher is vulnerable to statistical analysis. (Kendall, 2008). Therefore,
a Histogram would be the most effective tool to use. The Histogram can be used to show "the relative frequency
of each of the characters in ... Show more content on Helpwriting.net ...
Of the three ciphers discussed (Caesar, Vigenère, Playfair), what are their relative degree of security and why?
Using the entropy tool in CrypTool on the following ciphertext:
SDAHFOWGRABSSRERIVBYBSCIMQTFNIVETGHBSNQCNCSDTDHBSNQCDECNICIFOTIC
I came up with the following results:
Caesar 4.18
Playfair 4.46
Vigenère 4.59
According to our lab assignment, "generally speaking, a high calculated value is considered less likely to be
deciphered by a cryptanalyst." (CSEC 630 Lab Assignment 1 – Introduction to Cryptography, n.d.). Therefore, it
appears that the Vigenère cipher is the most secure, followed by the Playfair and then the Ceasar.
Q5. For each of the following say whether ECB or CBC would be most appropriate and give a brief explanation
as to why.
a. an online bank statement [10 points]
b. an encrypted VoIP session [10 points]
c. viewing of a website using TCP/IP
According to our text Security Engineering by Ross Anderson, ECB is "adequate for many simple operations
such as challenge–response and some key management tasks; it's also used to encrypt PINs in cash machine
stations". (Anderson, 2008). However, "using ECB to encrypt message of more that an one block length...such as
bank payment messages, would be foolish, as messages could be subject to

What Its Primary Purpose, Functionality, And Processes?
What its primary purpose, functionality, and processes? PGP is software that gives your electronic mail privacy.
It is a combination of public and private key which gives security services for electronic mail messages and data
files. It does this by encrypting your mail so that nobody but the intended person can read it. It enables two
people communicate by e–mail, with the greatest probability that no one but the sender and receiver can read the
text. It is designed to be run from command line. PGP has been ported successfully too many different platforms,
including DOS, the Macintosh, OS/2, Unix (just about all flavors), VMS, the Atari ST, Acorn RISC OS
(Archimedes), and the Commodore Amiga. The free versions of PGP are available for noncommercial use only.
For commercial use we need to buy PGP from PGP, Inc. MIT has released the free version of PGP 5.0 for
windows95 and Macintosh. PGP is still in development and new versions will emerge. PGP is used to send
messages confidentially. It can decrypt any type of messages in the form of text, message, GIF and program. A
word processor use swap files and automatically back up files. For example: A document is written in MS–word
when I save the file with .doc extension MS–word automatically saves a copy with .Bak extension which is
nothing but a backup file. Also, whenever I edit the file MS–word will also save the data automatically. Let's
understand what the purpose of using PGP? People who work together need to share

Code For Finding Key Length, Key And Plain Text
CODE IN JAVA Code for FINDING KEY LENGTH, KEY AND PLAIN TEXT TEXT DECRYPTION public
static void main(String[] args) { String encrytedString =
"OVVMEHINLHQGEANGPIRTICMYXUMSAMIABNQWEFOUZEEALHKTL" +
"RBOYELRPGPCSZMHMCOJQZTTLRLAFCLRAYUTLNLKZTMEMRKDMFIVBEEEMJEOXUMQUN" +
"KNVJFHIRFKOUXVWTQRVNVCULHYGABARQLUINPBWQUNKSWXUTAUQRQTLRZKETSSBNQ"
+
"PEEBEIERGJGOKXBBNQGEZMEAUGNVZFHMASNAWKYIJUAQGWYQECBCGSAMAGUGDINZU"
+ "XDXUQTSSEVLZTEHHKNQSWNAYTEXHKQQDLRZGDMESNKOTMBVGFEPLQTFOEYQIQSEAL"
+ "ZTECJIRWEHBNLFOKRBNQREYQIQWEFDKDYKYIJFOJVVJTEVVVYGCLNXRQAWNVZFEQC" +
"MXMNHGPUGGLGBUTEVFMRRTLNBVQRLNXYUTANAUZLCGPKBETCMXFHEGPGPMEQMNQRW"
+ "BAGHAKRENQNXUMEYEXVVZTEOVBITERJPKZIQNLAOHIFAYTEWNQJFOLRZYQLJAWZUN" +
"EIMXKHSCMLGLXBVKFHSHONUWSABNMVINVEBETCMXUNQLSOFCLRVGFAPYAUGPHBMYH"
+ "EVLEKXLAVBNAUXZIENEMGAGXWELAVQPTRZZTAXZIQQSTRWVXELBBZQMTRZKPSLREK"
+ "ZTSADKDYQHKNBLINAKPAXUIBUNKSWAZDSHBGZEAXQTPOJECRQARQDOZEKNZZTAXZI" +
"QQSXUMSEOYEITPCEZWSULIGPGFMEXMYFHIZJOFTIEITPARQJGDLILAASAVNVJEUGU" +
"BNUNKFBNMTQNSKOHMYLXQNWJMKFTIZXKDEHVWTXYAVANBESCTKWNIJBNMTXUMTFHI"
+ "LEUGLHABHQSSFBOZGCNJUGTMGGUGKRBE"; Decryption decryption = new Decryption(); String
decryptedString = decryption.findDecryptedString(encrytedString); System.out.println(decryptedString); } }
DECRYPTION import java.text.DecimalFormat; import java.util.ArrayList; import java.util.Collections; import
java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; //

Encryption in Today's Information Systems
In today's world of instant connectivity and information at users' fingertips, it's vital that sensitive information is
safeguarded against those who seek to do personal harm and profit from gaining access to the data. The key
behind keeping information safe is the method in which it's protected and encrypted. In order to appreciate how
information is secured, users must understand the encryption concepts behind it. To do this, one must
comprehend the current encryption standards, the trends and developments in encryption technology, the
importance of securing data, the government's regulations pertaining to encryption, the companies involved in
research and implementation, the implications of leaked or stolen data, and a brief look into ... Show more
content on Helpwriting.net ...
When a fellow general received the message, he would wrap the paper around his corresponding scytale to
decipher the message (Tyson 2014). Since the advent of computers though, encryption has become increasing
important and relies almost solely on cryptographic means to secure information. When speaking about
encryption today, it refers more to the process rather than the mathematical formulas used to scramble data. The
basic idea behind encrypting a computer message is such that it is scrambled with a sequence of random bits,
known as a key, and only parties with the corresponding key can transpose it back into a comprehensible format.
These keys are created via a cipher, otherwise known as an algorithm. When a user sends a message, known as
the plaintext, across a network, the computer applies an algorithm to the information to encode it, resulting in a
ciphertext (Encryption Basics 2014). This method can be best summarized visually: Plaintext message +
encryption algorithm + secret key = Ciphertext Ciphertext + corresponding key + decryption algorithm =
Plaintext message Generally speaking, modern encryption techniques fall into one of two categories – symmetric
(homogeneous) and asymmetric (heterogeneous). Symmetric encryption is a system of communication whereby
both parties share the same key to encode and decode a message. The Spartan generals used this method with
their scytales.

Annotated Bibliography On The Security Essay
security, although these schemes are still not semantically secure. So far, deterministic PEKS schemes can
guarantee semantic security only if the keyword space has a high min–entropy. Otherwise, an adversary can
extract the encrypted keyword by a simple encrypt–and–test attack. Hence, deterministic PEKS schemes are
applicable to applications where the keyword space is of a high min–entropy. III. PROBLEM DEFINITION One
of the prominent works to accelerate the search over encrypted keywords in the public–key setting is
deterministic encryption introduced by Bellare et al. An encryption scheme is deterministic if the encryption
algorithm is deterministic. Bellare et al. focus on enabling search over encrypted keywords to be as efficient as
the search for unencrypted keywords, such that a ciphertext containing a given keyword can be retrieved in time
complexity logarithmic in the total number of all ciphertexts. This is reasonable because the encrypted keywords
can form a tree–like structure when stored according to their binary values. Search on encrypted data has been
extensively investigated in recent years. From a cryptographic perspective, the existing works fall into two
categories, i.e., symmetric searchable encryption and public–key searchable encryption. The disadvantages of the
system is, Existing semantically secure PEKS schemes take search time linear with the total number of all cipher
texts. This makes retrieval from large–scale databases prohibitive. Therefore,

Julius Caesar Research Paper
Suetonius tells us that Julius Caesar enciphered his dispatches by writing D for A, E for B and so on [742]. When
Augustus Caesar ascended the throne, he changed the imperial cipher system so that C was now written for A, D
for B, and so on. In modern terminology, we would say that he changed the key from D to C.
The Arabs generalized this idea to the monoalphabetic substitution, in which a keyword is used to permute the
cipher alphabet. We will write the plaintext in lowercase letters, and the ciphertext in uppercase, as shown in
Figure 5.1.
CYAN RWSGKFR AN AH RHTFANY MSOYRM OYSH SMSEAC NCMAKO; but breaking ciphers of this
kind is a straightforward pencil and paper puzzle, which you may have done in primary school. The trick is that
some letters, ... Show more content on Helpwriting.net ...
An example should explain all this. Suppose you had intercepted a message from a wartime German agent,
which you knew started with "Heil Hitler," and that the first 10 letters of ciphertext were DGTYI BWPJA. This
means that the first 10 letters of the onetime pad were wclnb tdefj, as shown in Figure 5.3.
Once he had burned the piece of silk with his key material, the spy could claim that he was actually a member of
the anti–Nazi underground resistance, and that the message actually said "Hang Hitler." This is quite possible, as
the key material could just as easily have been wggsb tdefj, as shown in Figure 5.4.
Now, we rarely get anything for nothing in cryptology, and the price of the perfect secrecy of the one–time pad is
that it fails completely to protect message integrity.
Suppose that you wanted to get this spy into trouble; you could change the ciphertext to DCYTI BWPJA, as
shown in Figure 5.5.
During the World War II, Claude Shannon proved that a cipher has perfect secrecy if and only if there are as
many possible keys as possible plaintexts, and if every key is equally likely; therefore, the one–time pad is the
only kind of system that offers perfect secrecy [694,

Ch01-Introduction
Introduction 1 Defining Security The security of a system, application, or protocol is always relative to – A set of
desired properties – An adversary with specific capabilities For example, standard file access permissions in
Linux and Windows are not effective against an adversary who can boot from a CD 2 Security Goals Integrity
C.I.A. Confidentiality Availability 3 Confidentiality Confidentiality is the avoidance of the unauthorized
disclosure of information. – confidentiality involves the protection of data, providing access for those who are
allowed to see it while disallowing others from learning anything about its content. 4 Tools for Confidentiality
Encryption: the ... Show more content on Helpwriting.net ...
For example, the designers of an online music system may specify policies that describe how users can access
and copy songs. – Permissions, which describe the behaviors that are allowed by the agents that interact with a
person or system. For instance, an online music store may provide permissions for limited access and copying to
people who have purchased certain songs. – Protections, which describe mechanisms put in place to enforce
permissions and polices. We could imagine that an online music store would build in protections to prevent
people from unauthorized access and copying of its songs. 12 Authenticity Authenticity is the ability to
determine that statements, policies, and permissions issued by persons or systems are genuine. Primary tool: –
digital signatures. These are cryptographic computations that allow a person or system to commit to the
authenticity of their documents in a unique way that achieves nonrepudiation, which is the property that
authentic statements issued by some person or system cannot be denied. 13 Anonymity Anonymity: the property
that certain records or transactions not to be attributable to any individual. Tools: – Aggregation: the combining
of data from many individuals so that disclosed sums or averages cannot be tied to any individual. – Mixing: the
intertwining of transactions, information, or communications in a way that cannot be traced to any individual. –
Proxies:

Encryption: The Nazi Army Of Germany
Before the major advances in encryption in the 1970s, it was primarily used by governments and their militaries.
It allowed governments to have protected communication with their allies. One government could send
encrypted message concerning a common enemy to their ally and if the message was intercepted by that enemy,
the message would remain secret and unreadable to the enemy. Militaries used encryption to communicate plans
and troop movements and location. The Nazi Army of Germany during World War II developed an encryption
that at the time was impossible to decode without the cipher. The Germans could keep track of their extensive
submarine fleet in the North Atlantic without fear of the Allies discovering the locations of the submarines.

Hill Cipher
CioheWednesday, April 13, 2016
University of Botswana
ISS 334 LAB 2 ASSIGNMENT
Ndlovu.I 200902852
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ISS 334 Lab 2 Assignment
Page 1 of 27
Wednesday, April 13, 2016
Contents
1.
Hill Cipher Description .......................................................................................................................... 3
2.
Question ................................................................................................................................................ 3
3.
Implementation .................................................................................................................................... 3
3.1.
Hill Cipher Encryption and ... Show more content on Helpwriting.net ...
Step 3 is the same as Step 2 but using a different matrix multiplication to find the key. All the programs have
written in java using Dr. Java.
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3.1. Hill Cipher Encryption and Decryption

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3.1.1. Part 1
Class Basic the class has the indexOfChar and indexAtChar method.
The first method matches characters of a string to the alphabet and returns a numeric value, the second method is
used to return a char which is located at the position int pos.
Class Hill has an object basic of the class basic so as to access the methods from the basic class, this is done later
on in the program.
Class Hill also contains method Hill, this ensures that the matrix we are using is a 2X2 matrix, that's why the
variable block=2.
The method reads the key matrix. The user will enter in the first number and press "enter" and do this until the
fourth number is entered. The assumption is that we are using a 2x2 matrix as the key size.
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3.1.2. Part 2
The method KeyInverse also reads 4 integers which are stored to the double array Key[][] and uses them for the
decryption key.
The method encryptBlock is

Purpose Of Encode Information
To encode information, is to change data from one form to another through specific formulae/rules for a
specified purpose. Encoding is used every day by way of encryption, compression, data processing, conversion
and storage. Notable encoding systems include character encoding, video encoding, HTML encoding and URL
encoding.
Encryption
For information to be private and secure, encryption is used. A piece of information can be encrypted by
changing each of the characters in the data to something different. The encrypted information can then be
decrypted to find out the original information. It is important for information to be encrypted so that only the
person that has sent and the person receiving the information can see it. Without ... Show more content on
Helpwriting.net ...
One of the ways that a message encrypted with a Caesar Cypher can be unencrypted is through a 'brute force'
attack. This type of attack is where all possible combinations of keys are tried and tried until the message has
been unencrypted. Due to the number of possible rotations being limited to only 25 (as there are only 26 letters
in the alphabet) and the speed at which modern computers can operate, a message with Caesar Cypher
encryption can be unencrypted within seconds. Although, with a larger number of cipher keys the time to
unencrypt the message will increase, but even with a larger key set, the alternative encryption solutions (RSA,
Triple DES and AES) take far long to solve, years compared to only hours with a substitution cypher. A Caesar
Cypher can also vulnerable to frequency analysis attacks, this is when the frequency of each the letters in an
encrypted message are recorded and compared with the most commonly used letters in the English language to
find the rotation amount and then decrypt the message. Longer messages are easier to decrypt using this attack
method as there are more letters that can be analysed and a pattern can be spotted quicker than that of a short
message. For modern data encryption methods to be secure, they must be able to prevent brute force and
frequency analysis attacks for a large period of time. The time it takes to decrypt a message is how encryption
methods can delay

Using Des With A Password
CS 6520 Assignment – 2 Sahithi Madala WM8573 Question 1 The first method, the computer is to use DES with
a password as a key to encrypt plain text. In this case the attacker will have both ciphertext and the plain text
though the physical security is difficult to maintain. This key cannot be further used for the decryption process.
So with these mentioned limitations, we DES has strong encryption method which is always difficult for the
attacker to break. Considering the example mentioned in the question (64bits of 0s). In my opinion the second
method is much secure and authenticated than the first method, but close to it. Because in the password field, the
input is being entered is plain text and the key being fixed. Implementing the ... Show more content on
Helpwriting.net ...
Now, when we consider the two XOR operations in the above figure shown. If the plaintext and key used for
encryption are both complemented, then the inputs given to the first XOR are also complemented. The output,
then, is the same as for the uncomplemented inputs. Further down, we see that only one of the two inputs to the
second XOR is complemented, therefore, the output is the complement of the output that would be generated by
uncomplemented inputs. b. In a chosen plaintext attack, if for chosen plaintext X, the analyst can obtain Y1 =
E[K, X] and Y2 = E[K, X '] An exhaustive key search requires only 255 rather than 256 encryptions. To see this,
note that (Y2) ' = E[K ', X]. Now, pick a test value of the key T and perform E[T, X]. If the result is Y1, then we
know that T is the correct key. If the result is (Y2) ', then we know that T ' is the correct key. If neither result
appears, then we have eliminated two possible keys with one encryption. Question 4 Stallings Problem 6.4: No.
For example, suppose C1 is corrupted. The output block P3 depends only on the input blocks C2 and C3 which is
shown in the image below. b). An error in P1 affects C1. But since C1 is input to the calculation of C2, C2 is
affected. This effect carries through indefinitely, so that all

Annotated Bibliography On International Encryption Subversion
Nicholas Gambini Crypto Final Paper Dr. Landquist Intro to Crypto International Encryption Subversion
Introduction: As implied by the fourth, ninth, and fourteenth amendments to the Constitution of the United
States, all citizens of the United States have a right to privacy. In the digital age, where all of our most important
and personal information is stored digitally, we must have a way to protect this digital content. To protect our
data we use encryption where contents of files are scrambled and distorted and can only be made legible by
someone who knows the decryption key. Governments in Europe, Asia, and America are currently engaged in
undermining the encryption and privacy rights of their citizens either by demanding backdoors or ... Show more
Apple responded with a case curiously omitted from the FBI's argument; a federal judge found it inconceivable
that the law could be used to compel a telecommunications provider to allow real–time tracking of a cellphone
without a search warrant (Lichtblau). As support for Apple grew, Director of Privacy at Stanford Law School,
Albert Gidari, LLM, published a paper detailing specifically why the FBI was wrong and why their argument
was useless. In his paper he discusses the Communications Assistance for Law Enforcement Act, or CALEA.
CALEA details what is and isn't lawful assistance from telecommunications companies to the government.
Within section 1002 lies these details: (1) Design of features and systems configurations. This subchapter does
not authorize any law enforcement agency or office (a) to require any specific design of equipment, facilities,
services, features, or system configurations to be adopted by any provider of a wire or electronic communication
service, any manufacturer of telecommunications equipment, or any provider of telecommunications support
services; (b) to prohibit the adoption of any equipment, facility, service, or feature by any provider of a wire or
electronic communication service, any manufacturer of telecommunications equipment, or any provider of
telecommunications support services. (Schneier) What this means is that it is unlawful for

Information Security And Aggregatable Contexts
Conventional communicate encryption plans enable a sender to safely communicate to any subset of individuals
however require a trusted gathering to convey unscrambling keys. Gathering key understanding conventions
empower a gathering of individuals to arrange a typical encryption key by means of open systems with the goal
that lone the gathering individuals can decode the ciphertexts encoded under the common encryption key,
however a sender can't prohibit a specific part from unscrambling the ciphertexts. In this paper, we connect these
two thoughts with a half and half primitive alluded to as contributory broadcast encryption (ConBE). In this new
primitive, a gathering of individuals arrange a typical open encryption key while every part ... Show more
Disturbance tolerant system (DTN) advancements are getting to be plainly effective arrangements that enable
hubs to speak with each other in these outrageous systems administration conditions. Ordinarily, when there is no
limit to–end association between a source and a goal match, the messages from the source hub may need to sit
tight in the transitional hubs for a generous measure of time until the point when the association would be in the
end built up.
The framework proposes a characteristic based secure information recovery plot utilizing CP–ABE for
decentralized DTNs. The proposed plot highlights the accompanying accomplishments. In the first place, quick
property disavowal upgrades in reverse/forward mystery of secret information by decreasing the windows of
helplessness. Second, encryptors can characterize a fine–grained get to approach utilizing any monotone get to
structure under qualities issued from any picked set of specialists. Third, the key escrow issue is settled by a
without escrow key issuing convention that adventures the normal for the decentralized DTN design. The key
issuing convention produces and issues client mystery keys by playing out a safe two–party calculation (2PC)
convention among the key specialists with their own particular ace privileged insights. The 2PC

The Basic Concepts Of Cryptography Essay
Background
Cryptography is known as the method of writing secrets. The secured data and all of information from any
external or internal hacks. Therefore, it provides confidentiality, integrity, authenticity and non–repudiation to
secure data. The basic concepts of cryptography will be based on two terms namely plain text and cipher text.
Plain text represents the message generated originally and cipher text is the message which is the encrypted text.
We would decrypt the encrypted cipher text to get our original message.
Cryptography provides the practitioner with the following services or objectives: Confidentiality is the method
used to have all the data to be accessed by an authorized personnel only and helps keep the data secure. It even
monitors the channel to have all the data transmitted between users over a given time period between two points
and is well protected of the traffic flow and analysis. Integrity is a method requiring the computer systems
components and transmitted data to be capable of changes only by authorized users. Modification includes
writing, changing, changing the status, deleting, creating, and the delaying or replaying of transmitted messages.
It is important to point out that integrity relates to active attacks and therefore, it is concerned with detection
rather than prevention. Moreover, integrity can be provided with or without recovery, the first option being the
more attractive alternative. Authentication is a service that is

Encryption Is Just A Fancy Word For Coding
Encryption is just a fancy word for coding. When we talk about encrypting we really just mean turning
information into really a hard to read secret code. Let's say we have some secret agents in a movie and suppose
there is an agent working in Washington DC they need to send a message to another agent in Russia. The best
way for them to do this is by the two of you to meet up in advance, in person, and agree on a method of locking
and unlocking all the messages they will send and receive in future.This method is called a secret key, because
only the two of you will have access to it. When people want to find out what their saying to each other the
attack is called a chosen ciphertext attack,CCA. In cryptography, ciphertext or cyphertext is the result of
encryption performed on plaintext using an algorithm, called a cipher. It is an attack model for cryptanalysis in
which the cryptanalyst gathers information by choosing a ciphertext and obtaining its decryption under an
unknown key. Cryptanalysis is the study of analyzing information systems in order to study the hidden aspects of
the systems. People use encryption for a theoretical wall against anyone that wants to find out what is inside.
The government needs to be able to access information on phones, computers or social media accounts because
of illicit online activities:robbery, sexual predators and planned murder. The government needs to know about
these inappropriate activities so they can stop this behavior. Known

Nt1330 Unit 4 Dthm Paper
4 THE DIFFIE–HELLMAN KEY EXCHANGE ALGORITHM
Whitfield Diffie and Martin Hellman proposed a famous key exchange protocol in 1976 [16]. Diffie–Hellman
key exchange (D–H), is a method for exchanging cryptographic keys that allow two parties to share public key
for encrypting their messages over an insecure communication channel [16].
We consider two Clients, X and Y [5,6].
1. Both of the clients must agree to use large prime p and nonzero integer g which is a primitive root modulo p.
2. They share p and q and make it public together.
3. A picks a secret integer m and keeps it secret.
4. B picks a secret integer n and keeps it secret.
5. X computes: A ≡ gm (mod p)
6. Y computes: B ≡ gn (mod p)
7. X and Y exchanging A, B (X sends A to Y and Y ... Show more content on Helpwriting.net ...
In the encryption phase of the protocol:
1. A and B Shares their Diffie–Hellman's public key over communication channel
2. A, generates two 128–bit random numbers (αR and βR)
3. A, calculates hash of αR by RIPEMD–160 hash function
4. A, encrypts βR by Diffie–Hellman's public key
5. A, calculates hash of 3th step by SHA–256 hash function (αS is the result)
6. A, calculates hash of βR by SHA–256 hash function (βS is the result)
7. A should bitwise XOR αS and βS (The result of this step is Main Key (MK) for USEA)
8. A, encrypts plain text (Message) by USEA with MK (Cipher text is the result)
9. By Adding Result of the 4th step and αS and result of the 8th step (Cipher text), Final cipher text (Cipher text
with headers (CTH)) is the encrypted message of A.
In the decryption phase of the protocol:
For decrypting the CTH of A, B deciphers the result of the 4th step by itself Diffie–Hellman Private Key and
achieves βR. Then calculates hash of βR by SHA–256 hash function. Finally, with bitwise XOR αS and βS, B
can obtain MK and decrypt Cipher text. Figure 3 shows the structure of

Nt1310 Unit 3 Assignment Of Encryption Techniques
1. Type of operations used for transforming plaintext to cipher text. All encryption algorithms are based on two
general principles. Those are substitution, in which each element in the plain text is mapped into another element
and transposition in which elements in the plaintext are rearranged. The fundamental requirement is that no
information be lost. Most systems referred to as product systems, involved multiple stages of substitution and
transposition [2].
2. The number of keys used: If sender and receiver use the same key, the system is referred to as symmetric,
single key or secret key conventional encryption. If the sender and the receiver each uses a different key the
system is referred to as asymmetric, two key, or public–key encryption

Nt1330 Unit 1 Assignment 1 Algorithm Essay
The algorithm is executed by the owner to encrypt the plaintext of $D$ as follows:
begin {enumerate}
item [1:]for each document $D_i in D$ for $i in [1,n]$ do
item [2:]encrypt the plaintext of $D_i$ using also $textit{El Gamal}$ cipher under $textit{O's}$ private key
$a$ and $textit{U's}$ public key $U_{pub}$ as $Enc_{D_i}= U_{pub}^a times D_i $
item [3:]end for
item[4:] return $textit{EncDoc}$
end{enumerate}
subsubsection{textit{textbf {Retrieval phase}}} Include three algorithms as detailed below:
begin{enumerate}
item [I–] $textit{Trapdoor Generator}$: To retrieve only the documents containing keywords $Q$, the data user
$U$ has to ask the $O$ for public key $O_{pub}$ to generate trapdoors; If $O$ is offline these owners' data
can't be retrieved in time. If not, $U$ will get the public key $O_{pub}$ and create one trapdoor for a
conjunctive keyword set $Q={q_1,q_2,...,q_l}$, using $textsf{TrapdoorGen}(Q, PP, PR$) algorithm. Firstly,
the data user combines the conjunctive queries to make them look like one query, $Tq={q_1| q_2|...| q_l}$,
then $U$ will compute the trapdoor of the search request of concatenated conjunctive keywords $textit{Tq}$
under his private key $b$, $Tw=H_1(Tq)^b in mathbb{G}_1 $. Finally, $U$ submits $Tw$ to the cloud server.
... Show more content on Helpwriting.net ...
Then $S$ test $textit{BF}$ in all $r$ locations, if all $r$ locations of all independent hash functions in
$textit{BF}$ are 1, the remote server returns the relevant encrypted file corresponding the $ID_i$ to $U$. In
other words searchable index $I_D$ can be used to check set membership without leaking the set items, and for
accumulated

Nt1310 Unit 4 Performance Analysis
4 PERFORMANCE ANALYSIS There are various performance factors which are used to analyzed the different
encryption algorithms.
1. Throughput performance
It is the higher rate of production or maximum rate at which data can be processed which belong to may be
delivered over a physical or logical link. It may be affected by various factors such as medium, available
processing power of the system components and end–user behavior.
2. Key Length Size
In the encryption process, the key management is the important factor to shows the how the data is encrypted.
The symmetric algorithm uses a variable key length which is longer. So, the key management is a huge aspect in
encryption processing for control operation of the cipher.

Dnssec Case Study
DNSSEC is a set of DNS extensions that authenticates the origin of zone data and verifies its integrity by using
public key cryptography. That is, the extensions permit DNS clients to ask the questions, "Did this DNS data
really come from the zone's owner?" and "Is this really the data sent by that owner?"
DNSSEC provides three distinct services: key distribution by means of KEY resource records stored in the zone
files, origin verification for servers and data, and verification of the integrity of zone data. DNSSEC relies upon
a cascading chain of trust: The root servers provide validation information for the top–level domains, the top–
level domains provide validation information for the second–level domains, and so on.
Public key cryptosystems

Essay On Cryptography
5.1 Introduction: Two set of text images and one true sample image is taken for cryptography. In this proposed
work these three images are encrypted into various shares through MATLAB, so that after compiling specific
number of share the original image is visible. After encryption the performance analysis is done with the help of
PSNR and MSE values. 5.2 Main Input Images In the current work various set of text images are used for crypto
analysis. The sample image 1 and sample image 2 are the synthetically generated images for our own study. The
Reference image 1 and the Reference image 2 are the image taken from the work done by base papers. And for
the complex parametric evaluation a true colour image is also used for efficiency ... Show more content on
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In Figure 5.4(a) alphabet A from the original sample image is converted into cyan by subtracting green and blue
pixel from the original 256 pixel. (a) (b) (c) Figure 5.4: Image 1 CMY and Haftone Conversion (a) (b) (c) Figure
5.5: Image 2 CMY and Haftone Conversion Similarly in figure 5.4(b) alphabet B is converted into magenta by
subtracting red and blue pixel from the original 256 pixel whereas yellow is observed in alphabet C due to the
subtraction of red and green pixels shown in figure 5.4(c) 5.5 RESULTANT SHARES & FUZZY ANALYSIS In
this section the shares are generated using the standard Floyd Steinberg half tone method [5] on the image taken
after merging the CMY components. Results of the Encryption of original sample image 1 are resulted into four
shares which is share 1, share 2, share 3 and share 4.shown in Figure 5.6. Share 1 Share 2 Share 3 Share 4 Figure
5.6: Shares for different input sample images 1 Share 1 Share 2 Share 3 Share 4 Figure

Analysis Of Public Key Encryption
1 INTRODUCTION
Public–key encryption is a powerful mechanism for ensuring the confidentiality of stored and transmitted data.
The traditional encryption is regarded as a method to share data to some targeted person or device that the sender
knows. This means the sender knows specifically which user he wants to share with. However, in many systems
the message sender will want to share date with a group of people whose credentials or attributes accord to some
access policy set by the sender.[8][9]A new vision of encryption[10]was presented, where the sender can express
how he wants to share data in the encryption algorithm itself. The sender will give an attribute formula to
describe the users who can decrypt this data. Then only those whose ... Show more content on Helpwriting.net ...
Then, users use their attribute private key to decrypt the cipher text. In this case it is the users attribute instead of
the traditional public key that is matched with their private key.
CP–ABE is extremely efficient and secure in the system in terms of the fine–grained access control of attributes.
Theoretically, based on some previous researches, this paper will simply introduce the algorithm scheme and
how it working. Practically, I will compare some libraries which implement CP–ABE and try to implement a
small program using these different libraries
2 BACKGROUND OF RESEARCH
In 2007, a new methodology for realizing Ciphertext–Policy Attribute
Encryption (CP– ABE)[3]under concrete and non–interactive cryptographic assumptions in the standard model
came out and a basic framework of this model was constructed. This scheme, referred as BSW scheme, uses
threshold secret sharing to enforce the policy. The main drawback of BSW scheme is the complexity and
computing time in decryption phase, which requires may expensive pairing and exponentiation operations. In
2009, there is a scheme of CP–ABE mentioned before was presented, which is efficient and provable secure.
[5]This scheme can express any access policy involving AND, OR and OF operator (threshold) by defining the
privacy policy through access tree instead of threshold secret sharing which

Improving Personal Health Records On Cloud Services
In the medical industry, it is critical to ensure the confidentiality of patients' personal health records when storing
and managing them. Before cloud computing surfaced, heath providers used local servers and hard drives to
store their records and data. As cloud computing has been becoming more and more popular, many healthcare
providers are using the cloud to store and manage their sensitive data. This paper will investigate the different
access control models, Role–Based Access Control and Attribute–Based Access Control, to validate the
confidentiality of data when storing and managing personal health records on cloud services. The competitive
evaluation of the access control models will be done to identify possible flaws in these ... Show more content on
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1.1 Personal Health Record
A personal health record is a record of medical data or information pertaining to a particular individual that is
managed and maintained on a system, in this case a cloud system. This system is a centralized place where the
individual can store and manage their health data wherever and whenever they wish as long as there is a
connection to the internet present.
1.2 Cloud Computing
Cloud computing is the practice of storing, managing, and processing data on a network of remote servers hosted
on the internet, instead of locally on servers or hard drives. Cloud computing has unlimited storage, capacity and
scalability, as well as back up and recovery systems. It allows you to access your data anywhere with an internet
connection. However, security and privacy is a concern when managing confidential data.
1.3 Data Confidentiality
Confidentiality is denoted as securing a system to protect sensitive data from being exposed to the unauthorized
user. Confidentiality is extremely important when data is stored on a cloud server remotely. The data owner is
not aware of where their data is stored and of who is able to access their personal data leaving concerns of how
confidential their data actually is.
1.4 Access Control
Access control is the technique to ensure security in a system. To

Unit 7 File Encryption Paper
Encrypting files is an effective way of securing information over the internet and protect the confidentiality and
integrity of data. 128–bit encryption is the mathematical equivalent of key combinations used by encryption and
decryption algorithms to keep data transmission secure. The strength of a key is in the key length, and numbers
of bits in a key, the longer the key the more secure or hard it will be to crack the encryption.
An encryption algorithm takes the original message and encodes it using the encryption key and creates an
encrypted message. The only way to retrieve the original message is by decrypting the message using the
encryption key. If the encryption key uses a 128–bit key is the same as saying that there are 128² possible key
combinations. Algorithms are classified ... Show more content on Helpwriting.net ...
Experts believe that a128–bit encryption will be around for the next ten years, however the Military and uses
196–bit and 256–bit system. These systems were designed by the Advanced Encryption Standard (AES) for
highly sensitive data. Truly to protect data companies must establish a strong foundation of protecting data over
the secure socket layer. Employees do rely on data centers and for protection of their data from being sniffed to
the dark USENET that is the main internet (Bruce 2000).Crypto management has strong effective data
management and combines both crypto processing and acceleration to our data at very high speed that even
network sniffers can no longer get our credentials and use them for fraud. Cryptography today is what we use to
protect our online identity while browsing the internet, without encryption our online anonymity will be insecure
on daily basis. Transacting online business is risky if you don't have an updated web browser since third parties
will be injecting malwares and key loggers into your systems. Many password generation systems are based on a
one way harsh

The Impact Of Cryptanalysis Using Advanced 3d Playfair...
Impact of Cryptanalysis using Advanced 3D Playfair Cipher
Gaurav Kumawat1, Sandeep Upadhyay2
1 Department of Computer Sc. & Engg, Techno India NJR Institute of Technology
1gaurav_kumawat2002@yahoo.com
2 Department of Computer Sc. & Engg, Techno India NJR Institute of Technology
2sandeepupadhyay30@gmail.com
Abstract. The Playfair cipher is a manual symmetric encryption technique and was the first literal digraph
substitution cipher. The cryptanalysis of the Playfair cipher is also aided by the fact that a diagram and its reverse
will encrypt in a similar fashion. The paper proposes to encrypt/decrypt by choosing 216 ASCII characters out of
256 ASCII characters. The 216 characters includes the most frequently & popularly usable characters like 26
upper & lower case alphabets, 10 numerals and 154 most commonly used special characters of ASCII character
set. 40 special characters that are less frequently used are exempted. 2D–Playfair cipher is a case sensitive cipher,
as it requires only 26 alphabets rather than 52 alphabets (including lower and upper case both).The theme of this
paper is to provide security for the data that contains a wider coverage of alphabets numerals and special
characters in compare to 2D playfair cipher.
1 Introduction
Cryptography is the practice and study of techniques for secure communication in the presence of third parties.
The art of protecting information by transforming it (encrypting it) into an unreadable format is called cipher
text.

Nt1310 Unit 3 Assignment 1
1) Encryption can take place at several different layers of the protocol stack. Does encryption make sense at level
1 (the Physical Layer): Yes , it makes a sense in the physical layer. It is used for radio communication but yeah
mostly in miltary grade radio communication. For instance , there might be a blank noise while being actual
communication. Such a encoding does not process bytes it directly processes the electromagnetic waves so
encryption need to be implemented at physical layer. 2) Difference between encryption at level 2 and at level 3:
Data Link Layer encrytion encrypts all the data along a specific communication path, as in a satellite link, T3
line, or telephone circuit. Not only is the user information encrypted, but the ... Show more content on
Helpwriting.net ...
As switches focus is on providing LAN connectivity, the majority of threats come from inside the organisation
itself. Layer 2 attacks may also include MAC flooding or ARP poisoning. In order to mitigate these risks, it is
imperative network switches are hardened. Additional controls may include ARP inspection, disabling unused
ports and enforcing effective security on VLAN's to prevent VLAN hopping. OSI model Layer 3 attacks Layer 3
is the network layer and utilises multiple common protocols to perform routing on the network. Protocols consist
of the Internet Protocol (IP), packet sniffing and DoS attacks such as Ping floods and ICMP attacks. Because of
their layer 3 nature, these types of attacks can be performed remotely over the Internet while layer 2 attacks
primarily come from the internal LAN. To reduce the risk of these types of attacks, routers should be hardened,
packet filtering controls should be used and routing information should be controlled. OSI model Layer 4 attacks
Layer 4 is the transport layer and utilises common transport protocols to enable network communications. This
may include the Transport Control Protocol (TCP) and Universal Data Protocol

Access Control and Data Updation in Cloud Computing
We consider a cloud computing environment consisting of a cloud service provider (CSP), a data owner, and
many users [few with read and few with both read/write permission]. The CSP maintains cloud infrastructures,
which pool the bandwidth, storage space, and CPU power of many cloud servers to provide 24/7 services. The
CSP mainly provides two services: data storage and re–encryption. After obtaining the encrypted data from the
data owner, the CSP will store the data. On receiving a data access request from a user, the CSP will re–encrypt
the ciphertext based on attributes, and return the re–encrypted ciphertext. The data owner outsources a set of data
to the cloud. Each piece of data is encrypted before outsourcing. The data owner is responsible for determining
the access structure for each data, and distributing secret keys to each user. When a user wishes to access data, he
will first request appropriate keys from the data owner, and then request the CSP to download the ciphertext. If
his access right is effective when he requests the data, he can successfully execute decryption. The data owner is
the only one allowed to give read/write permission to users. Data users with write permission can perform the
updations and even delete the data within their effective time period. A typical cloud environment is shown in
Fig 1. Fig 1 A typical cloud environment 3.2 Design Goals The main objective of our scheme is to achieve, 1)
Data confidentiality: The data is encrypted

Essay On Cryptographic Primitives
Physically unclonable cryptographic primitives are promising for securing the rapidly grow–ing number of
electronic devices. Here, we introduce a new class of physically unclonableprimitives from layered molybdenum
disulfide (MoS2) by leveraging the natural randomnessof their island growth during chemical vapor deposition
(CVD). We synthesize a MoS2mono–layer film covered with speckles of multilayer islands, where the growth
process is engineeredfor an optimal speckle density. Using the Clark–Evans test, we confirm that the
distributionof islands on the film exhibits complete spatial randomness,i.e.true randomness. Such aproperty is
highly desirable for constructing unpredictable cryptographic primitives. The se–curity primitive is an ... Show
more content on Helpwriting.net ...
As a result, authentication of electronic devices andinformation has become increasingly important. Physically
unclonable functions (PUFs) areamong promising security primitives for entity identification or cryptographic
key genera–tion4,5. A variety of PUFs have used manufacturing variability6,7or materials disorders8–13for
generating a security keyon demand. Specifically, applying a challenge (such as anelectrical or an optical
stimulus) to a PUF produces a unique response (a security key).Hence, this concept generates security keys that
are unique for each electronic device. APUF construct must be easy to produce at low cost and yet have a
physical structure that isimpossible to replicate,i.e.physically unclonable. Notably, the physical unclonability
andthe uniqueness of the response are the core defining properties of a PUF5.Silicon–based PUFs have garnered
significant attention in the past decade as a poten–tial low–cost solution for securing digital systems due to their
compatibility with the com–plementary metal–oxide–semiconductor (CMOS) technology7. However, to date, all
siliconPUFs require extensive data processing to enhance the robustness and uniqueness of theirresponse5,14,15.
For instance, applying a number of procedures involving error correction,masking of unreliable bits, and addition
of helper data improves the robustness against envi–ronmental factors, while using other

Nt1310 Unit 3 Assignment 1-3 Reaction Paper
DES III challenge– it took 22 hours and 15 minutes to crack the message.
AES(advanced encryption standard)
It was first published in year 2001and is more mathematically efficient and elegant cryptographic algorithm [4].
Its main strength rests in the option for various key lengths. It allows to choose 128–bit, 192–bit, or 256–bit
key.it is exponentially stronger than the 56–bit key.it uses Permutation–Substitution that is, it involves a series of
substitution and permutation steps to create the encrypted block. Substitution is simply a mapping of one value to
another and permutation is the re–ordering of the bit positions for each of the inputs.there can be 2^128,2^192,
2^256 combinations of the key. Maximum amount of data that can be transferred

An Effective Method For Encryption
Abstract
An effective method for encryption of images using magnitude and phase manipulation of the image with the
help of a carrier image is described. Although it involves traditional methods like magnitude and phase
encryption, the novelty of this work lies in the fact that a private key as well as a carrier image is used for
encryption. An image to be encrypted and a carrier image is chosen and row wise one dimensional DFT is taken
for both the image. This is used for obtaining the row wise magnitude addition and phase addition which yields
the encrypted image. This encrypted image is subjected to one more level of encryption by performing column
wise magnitude and phase modulation. The final encrypted image is completely distorted and hence non–
intelligible. Performing the reverse operation it is found that the decrypted image is distortion less. 1
Image Encryption Using DFT
Introduction
Today web is going towards the multimedia data in which image covers the highest percentage of it. But with the
ever–increasing growth of multimedia applications, security is an important aspect in communication and storage
of images, and encryption is the way to ensure security [1]–[2]. Image encryption techniques try to convert
original image to another image that is hard to understand and to keep the image confidential between users, in
other word, it's important that without decryption key no one can access the content. Image encryption has
applications in internet communication,

Cryptology: Revolutionary War And World War II
A science vital in modern, everyday life. A word unknown to many. Key in both the winning of the
Revolutionary War and World War II. Used for security, communication, authentication, and encryption. Runs
not only the digital world, but cars, medical devices, and drones. What is this unheard science? This hidden
word? Cryptology.
Cryptology is derived from the Greek words, kryptos and logos. The literal meaning of cryptology is "hidden
study" or "the study of the hidden." The science of cryptology is split into two separate sciences, cryptography
and cryptanalysis. Cryptography is kryptos and graphein, meaning "hidden writing." Cryptanalysis is from
kryptos and analyein. It means "to loosen or untie the hidden." Cryptography and cryptanalysis ... Show more
The code used by runaway slaves and abolitionists was called the quilt code. Certain patterns on a quilt
represented a certain message. These quilts were thrown over the fences around the slave quarters. No suspected
anything because it was normal for people to air out their quilts and blankets this way. Other ways messages
were transmitted is through words such as "dry goods", "hardware", and "ten." Each word or number represented
different things or places. Slaves often sang songs called spirituals. Spiritual such as "Go Down Moses" and
"Wade in the Water" were used to tell slaves to do something or to alert them that people such as Harriet Tubman
was coming to help.
During the Civil War both the Union and the South used codes and ciphers to convey orders. The Confederate
generals and captain all used their own code, which, although it made it harder for the Union to decode, resulted
in other confederate generals being confused and unable to properly understand the messages. Sometimes, the
Confederates would even post the message in the paper to find anyone who could decode it. They also put
intercepted Union messages in the paper when they were unable to figure them out. Even though the codes
differed in the South, the North was still able to decode most of

Nt1310 Unit 1 Assignment
Now let's represent M by an integer between 0 and n − 1. If the message is too long, sparse it up and encrypt
separately. Let e, d, n be positive integers, with (e, n) as the encryption key, (d, n) the decryption key, n = pq.
Now, we encrypt the message by raising it to the eth power modulo n to obtain C, the cipher text. We then
decrypt C by raising it to the dth power modulo n to obtain M again. Formally, we obtain these encryption and
decryption algorithms for E and D:
C ≡ E(M) ≡ M e (mod n) (5)
M ≡ D(C) ≡ Cd (mod n) .
Note that we are preserving the same information size, since M and C are integers between 0 and n − 1, and
because of the modular congruence. Also note the simplicity of the fact that the encryption/decryption keys are
both just ... Show more content on Helpwriting.net ...
(6)
"gcd" means greatest common divisor.
The reason we want d to be coprime to (p − 1) (q − 1) is peculiar. I will not show the "direct motivation" behind
it; rather, it will become clear why that statement is important when l show towards 4 the end of this section that
it guarantees (1) and (2). We will want to compute e from d, p, and q, where e is the multiplicative inverse of
d.That means we need to satisfy
e d = 1 (mod φ(n)) . (7)
Here, we introduce the Euler totient function φ(n), whose output is the number of positive integers less than n
which are coprime to n. For primes p, this clearly becomes φ(p) = p − 1 . For n, we obtain, by elementary
properties of the totient function, that
φ(n) = φ(p) φ(q) = (p − 1) (q − 1) (8) = n − (p + q) + 1 .
From this equation, we can substitute φ(n) into equation (7) and obtain
e d ≡ 1 (mod φ(n))
which is equivalent to
e d = k φ(n) + 1
for some integer k.

By the laws of modular arithmetic, the multiplicative inverse of a modulo m exists if and only if a and m are
coprime. Indeed, since d and φ(n) are coprime, d has a multiplicative inverse e in the ring of integers modulo

Nt1310 Unit 6 Powerpoint
A. Setup: The setup phase takes input a security parameter . It selects a bilinear group of prime order p with b as
generator, and bilinear map The universe attribute is . It selects for attribute n, , and a random exponent . The
public key and master key is given by (1) (2)
Though is publicly known to all system parties, is kept secretly by trusted authority (TA).
B. Key Generation: The key generation phase takes set of attributes S as input and the secret key equivalent to S
is produced as output. Initially, it selects a random number from . Then, it calculates the key as (3)
C. Encryption: The

Introduction and Mechanics of Encryption
Introduction and Mechanics of Encryption
Encryption
The conversion of data into ciphertext, that cannot be easily understood by unauthorized people. It is the only
way to protect information in transit over the Internet. It is also a necessary part of defense–in–depth to protect
information stored on Web sites or in a public cloud.
Basic Encryption Methods:
Several methods are used to encrypt data before being sent over the Internet.
Symmetric Encryption
Symmetric method: same key used for encryption and decryption.
Advantage: Much faster than asymmetric encryption
Disadvantage:
1. Both sender and receiver need to know the shared secret key. 2. A separate secret key needs to be created for
use by each party with whom the ... Show more content on Helpwriting.net ...
This makes it harder to spot patterns in the ciphertext that reflect patterns in the original plaintext.
Encryption Algorithm
The nature of the algorithm used to combine the key and the plaintext is important. Secrecy is not necessary for
strength. Indeed, the procedures used by the most accepted and widely used encryption algorithms are publicly
available. Their strength is due not to the secrecy of their procedures, but to the fact that they have been
rigorously tested and demonstrated to resist brute–force guessing attacks. Therefore, organizations should not
attempt to create their own "secret" encryption algorithm, but instead should purchase products that use widely
accepted standard algorithms whose strength has been proven.
Policies for Managing Cryptographic Keys
This is often the most vulnerable aspect of encryption systems. No matter how long the keys are, or how strong
an encryption algorithm is, if the keys have been compromised, the encryption can be easily broken. Therefore,
cryptographic keys must be stored securely and protected with strong access controls.
Disadvantages of Encryption 1. Some sensitive information, such as process shortcuts, may not be stored
digitally and, therefore, cannot be protected by being encrypted. 2. Encryption protects information only in
specific situations.
For example, full disk encryption protects the information stored on a laptop in the event that it is

A Research On Cloud Computing
In cloud computing, to protect data from leaking, users need to encrypt their data before being shared. Access
control [6], [7] is paramount as it is the first line of defense that prevents unauthorized access to the shared data.
With the burgeoning of network technology and mobile terminal, online data sharing has become a new "pet",
such as Facebook, MySpace, and Badoo. Meanwhile, cloud is one of the most promising application platforms to
solve the explosive expanding of data sharing. In cloud computing, to protect data from leaking, users need to
encrypt their data before being shared. Access control is paramount that prevents unauthorized access to the
shared data. Recently, attribute–based encryption (ABE) has been attracted ... Show more content on
Helpwriting.net ...
Then the patient adopts CP–ABE scheme to encrypt the information m1 and m2 by different access policies
based on the actual need. For example, an attending physician needs to access both the patient's name and his
medical record in order to make a diagnosis, and medical researcher only needs to access some medical test
results for academic purpose in the related area, where a doctor must be a medical researcher and the converse is
not necessarily true. Suppose that the patient sets the access structure of m1 as: T1
{("Cardiology"AND"Researcher")AND"Attending Physician"}. Similarly, m2 is termed as:
T2{"Cardiology"AND"Researcher"} Apparently, the information needs to be encrypted twice if m1 and m2 are
encrypted with access structures T1 and T2, respectively. Two ciphertexts CT1 = {T1,C1,C1, ∀y ∈ Y1 : Cy ,C'y}
where Y1={"Cardiology", "Researcher", "Attending Physician"} and CT2 = {T2, C2,C2, ∀y ∈ Y2 : Cy ,C'y}
where Y2={"Cardiology", "Researcher"} will be produced [11]. In the Fig. 1, we can find that the two access
structures have hierarchical relationships where the access structure T1 is the extension of T2 [25]. The two
structures could be integrated into one structure T. If the two files could be encrypted with the integrated access
structure and produce ciphertext CT = {T , C1 ,C1, ∀y ∈ y1 : Cy ,C'y} where Y={"Cardiology", "Researcher",
"Attending Physician"}.Here, the components of ciphertext {T ,Cy

Annotated Bibliography On Information Security
1. Abstract
Information security is a major concept in today's industrial and computer era, so security must be higher to
protect the confidential data. Information security plays major role in computer and network security with the
use of different cryptography algorithms that includes the encryption and decryption of data with the uses of the
algorithm and the key. By means of text or numerical key for the encryption can be dangerous because with the
several hack attacks that a key can be broken. So I have proposed a new mechanism that will replace the text key
with the image pixels and can gain high security which cannot be easy to break without prior knowledge.
2. Introduction
For the decades to keep data secure and to convey the ... Show more content on Helpwriting.net ...
It takes plaintext and the key as input and follows some mechanism with the use of mathematical calculations to
convert the plaintext into the cipher text. Instead of using the key that is in the numerical and text format if we
use the set of the pixels of an image, then the algorithm will be able to generate the cipher text that will be really
hard to decode.
3. Research design
3.1 Basic theory – there are some primary and important components that play a vital role in the cryptography
are,
I. Plaintext: this is a regular text message that is in meaningful and in the readable format that needs to be
secured.
II. Cipher text: this is the result of the encryption process where we get the cipher text that is in scrambled and
unreadable format.
III. Algorithm: this is a core part of the cryptography where all transformations occur with some predefined
processes, rules and basic mathematical functions. This algorithm is responsible for encipher and decipher a
message.
IV. Key: secret key that is used to encrypt the message and used as input to the algorithm. And this key is also
shared between the sender and the receiver.
3.2 Processes used to carry out cryptography
I. Encryption: encryption is carried out on the sender side, hence transferred plain text into the cipher text and
forwarded over the network.
II. Decryption: decryption is carried out on the receiver side to translate the cipher text into the plaintext with the
same key that is used at the sender side.
3.3

AES1210 Unit 3 Assignment 1

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AES1210 Unit 3 Assignment 1