Neural Network and Expert System : [BE - IT]

 
  The subject "Neural Network and Expert System" is introduced as an elective subject in the final semester for BE -IT. The number of students who opt for this subject are very few compared to those opting GIS. The major reason why this subject  is not chosen as an elective subject is because it requires Artificial Intelligence as a pre-requisite. Moreover, the subject is a bit confusing and time consuming unlike 'Artificial Intelligence'. Students have managed to score averagely in this subject. And there have been rumors about a local author copy from Nirali Publications for this subject, but no confirm news - as I have not seen the copy myself!

Lets have a look at the syllabus for the subject :

Unit I :

Introduction to Artificial Neural Networks

Biological Neural Networks, Pattern analysis tasks: Classification and Clustering, Computational models of neurons, Basic structures and properties of Artificial Neural Networks, Structures of Neural Networks Learning principles

Unit II 

Feedforward Neural Networks

Perceptron, its learning law , Pattern classification using perceptron, Single layer and Multilayer feed forward Neural Networks (MLFFNNs), Pattern classification and regression using MLFFNNs, ADALINE : The Adaptive Linear Element, its Structure and Learning laws, Error back propagation learning, Fast learning methods: Conjugate gradient method, Auto associative Neural Networks, Bayesian Neural Networks

Unit III 

Radial Basis Function Networks and Pattern Analysis

Regularization theory, RBF networks for function approximation , RBF networks for pattern classification

Kernel methods for pattern analysis: Statistical learning theory, Support vector machines for pattern classification, Relevance vector machines for classification.

Unit IV 

Self organizing maps and feedback networks

Pattern clustering,, Topological mapping, Kohonen’s self, organizing map Feedback Neural Networks : Pattern storage and retrieval ,Hopfield model, Boltzmann machine, Recurrent Neural Networks

Unit V 

Expert Systems Architectures:

Introduction, Rule Based System Architecture, Non-Production System Architecture, Dealing with uncertainty, Knowledge Acquisition and Validation

Unit VI 

Shells and Case Studies

Expert System Shells , Knowledge System Building Tools for Expert System, Expert System tools case study – MYCIN – EMYCIN -ELIZA Knowledge Management (Wiki Web case study)

Download E-Books for

 Neural Networks & Expert System

An Introduction to Neural Networks

James Anderson

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Artificial Intelligence & Expert Systems for Engineers

Krishnamoorty, Rajeev

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Pattern Recognition & Machine Learning

C. S. Bishop

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Artificial Neural Network

Colin Fyfe

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Artificial Neural Network 

An Introduction to ANN Theory & Practice

P. J. Braspenning

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BE Syllabus - 2008 Pattern

   

  Pune University had launched the syllabus for BE 2008 Pattern on 4th June,2011for all streams of Engineering. The syllabus shows no major changes with comparison with that of 2003 course. But , one very promising change shown in the syllabus is : The introduction of two elective subjects in both the semesters. Hence this allows a student to make his engineering more specialized towards his field of interest. Now one can have a total of 4 elective subjects(2+2) in the final year Engineering.

    Apparently .....there were many rumors spreading out among the students about the internship becoming a part of the BE syllabus. Unfortunately......these remained untrue. The university has not included any internship program in the syllabus. Few senior members of the university have promised that the internship program may be included in the syllabus in the next syllabus update in 2012 pattern.

   The university has also upgraded the syllabus with the latest boomed subjects in the industry like Cloud Computing,VLSI & Digital System Design and Neural Networks for Computer Engineering.Similarly Multimedia Systems,Geo Informatics Systems,Advance Computer Networks,Advanced Graphics,Compiler Deign for IT.

   The concept of Open Elective has been introduced which allows a student to opt for a subject which may be from any other stream of Engineering and may be of keen interest to the student. This helps a student to make efficient utilization of the syllabus to study for a students respective project. Many a times it happens that students to need to study and research on study materials on subjects other than his own field..... this brings overload on a student. Now , the student can opt for his respective subject of interest which can help  a student learn more of his project from his syllabus.

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 Syllabus :

 BE Comp 2008 pattern :  Download  now

 BE IT      2008 pattern :  Download now

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Download 2008 pattern syllabus of 

BE for other Engineering Streams :

(Pune University) - 2008 Pattern (B.E.)

Mechanical

ENTC   

Production,

Electronics 

Civil 

Industrial Engg,

Production (Sandwich) 

Electrical

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What are Elective Subjects? [BE - All Branches]

Even before you have entered your Final Year[BE], most Engineering Colleges might have already compelled the students to submit their preferences for Elective subjects for the upcoming academic year. If this is not the scenario, then as soon as the 7th semester commences, your college would ask you to choose your elective subject.

   Today, we are publishing a few guidelines/ [Frequently Asked Question] which would give you little more clearer picture about What are Elective Subjects, What are the Advantages and Disadvantages of having an Elective Subjects.

Let us have a brief look at the Frequently Asked Question about Elective Subjects.

What is an Elective Subject?

Pune University has introduced the system of Elective subjects in the Engineering curriculum for all branches in the 7th and 8th Semester. This system allows a candidate to choose a particular subject for his/her course from a given set of options. Normally for each elective subject, a candidate has to select a subject from given 3 or 4 choices.

Why are Elective Subjects allowed in BE ? Why not have a regular pattern with same subjects for all students?

The University has wisely understood the diversity associated in each stream. In spite of students being in the same field ( say IT or Computer) the domain they choose for their career will most probably be different. Some may choose networking, some may choose Development, some may opt security and many others may choose Testing etc... the list is never ending.  Now since, the fields can be extremely diverse, the learning phase associated with this is also diverse. 

  The University has hence wisely introduced the system of elective subjects which allows a candidate to make his Engineering Degree more precise and more specialized for his domain of interest. On a simple note, a student can choose his favorite subject from the given options. 

How many Elective subjects are there in all ?

There are in all 4 Elective subjects in an academic year, 2 in each semester. Earlier before the 2008 pattern, there were only 2 Elective subjects allotted (One in each Semester). From the 2012 batch on wards , Pune introduced 2 Elective subjects in each semester i.e.  4 in an academic year.

Do we have Local Author Text Books like Techmax or Technical Publications for Elective Subjects?

Mostly NO, only a small crowd is associated with each Elective Subject,which makes  this deal not so profitable for local author publications. Very few subjects get published by publication like Nirali, Technical or Techmax.  For most other subjects , the only option is Reference Books.

Are Elective subjects difficult to study?

I would never say that any Elective subject is really difficult to study, but the reason why most BE students find this tough is 'Studying from Reference Books is mandatory in most cases'. You are left with no other option apart from studying from Reference Books when you don't have any local author books for the subject. The Elective subject are extremely vast and along with this,  finding the syllabus among different Reference books recommended by the Univresity is also not an easy task. But one good point about Elective subjects is that : The question papers are normally easy and quite predictable (in most case , but not always true).

What is Open Elective?

 Open Elective is a new step introduced by the university last year for the 2012 batch . It allows a candidate to choose a subject of his choice with syllabus designed by himself or the institution and then approved by the University. This technique allows a candidate to get subjects from other branches into his/her stream.

  We would be providing a detailed article about Open Elective, how to choose an Open Elective Subject and how to design it and then get it approved from the University.

Are Elective Subjects Scoring ?

 It completely depends on the subject you choose. But in most cases scoring above average in Elective Subjects is not as difficult as it was in other regular subjects.  

 In our next article , we would be posting about which Elective Subject should you choose, giving you detailed analysis about each Elective Subject offered

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Transposition Ciphers : Information Security

     
A transposition cipher is a method of encryption by which the positions held by units of plaintext (which are commonly characters or groups of characters) are shifted according to a regular system, so that the ciphertext constitutes a permutation of the plaintext. That is, the order of the units is changed.    

    Transposition ciphers are rather simple to understand. As the name implies, a transposition cipher involves the transposing – or moving – of characters from one place to another. See the example below. You’ll notice that all the characters used in the original text are also present in the transposed text.

Original Text: HELLO WORLD
Transposed Text: HLOOLOLWRD
Side note: This is an example of a rail fence cipher. A rail fence cipher is computed as follows. Notice the words are spelled out in columns, starting at the top left:

HLOOL
ELWRD

Cracking the Code

Cracking a transposition cipher can be accomplished with a process called anagramming.  Using language statistics, its relatively easy to crack a transposition cipher. If you know the frequency in which certain letter combinations occur, it is possible to crack a transposition cipher (see Alan Konheim’s book for an in-depth review).  In this case, we can crack the cipher as such:

The letter pairs HL, HW, HR and HD have a frequency of less than 0.0010 in the English language, so we’ll discard those for now. HE has a frequency of 0.0305. However, other arrangements – “HO” for example – are also candidates which shouldn’t be ruled out. In the end, you should get something like:

HE
LL
OW
OR
LD

While this method is rather reliable, remember that you’re also relying on statistical pattern matching, which is always error prone to some degree.

By themselves, transposition ciphers provide very little confidentiality.  Modern algorithms still use transposition, however only as a piece of the algorithm – not the whole.

Other methods for Transposition Cipher:

One of the oldest ways to do this was created by the ancient Egyptians and Greeks. It uses a stick called scytale . They would have used wooden sticks and parchment, but we're going to use poster tubes and adding machine tape!

How the scytale cipher works

1. Get a scytale and a strip of parchment.
2. Wrap your parchment around your scytale until the stick is covered. Try to avoid overlapping and gaps.
3. Write your message along the length of the stick, one character per pass of the paper. If you need more space, rotate the stick away from you and keep writing.
4. Unwrap the scytale and send the scrambled message to a friend with the same-diameter stick.
5. The friend then wraps his scytale with the encoded parchment. Since the diameters are the same, the message is clearly legible!

This technique was very useful in ancient battles; the Spartans are known to have used this rather extensively. Each general was given a stick of uniform diameter so that he could quickly encipher and decipher any message sent from other generals. Notice how quick and easy this is to use!

          However, it is also rather easy to crack. In a battle situation, the most likely way to crack this would be to steal a general's scytale. Then, each message could be read easily. However, it can be cracked even without stooping to theivery. As it ends up, the scytale is just a very old (and rather simple) version of a greater class of ciphers called matrix transposition ciphers. The way the simplest of these works is by picking a matrix of a fixed size (say, 6x10) and then writing your message across the rows. The encipherment step consists of writing down the letters in the matrix by following the columns. Here's a simple 6x10 example:

T	R	O	O	P	S	H	E	A	D
I	N	G	W	E	S	T	N	E	E
D	M	O	R	E	S	U	P	P	L
I	E	S	S	E	N	D	G	E	N
E	R	A	L	D	U	B	O	I	S
M	E	N	T	O	A	I	D

Where we've written the message:

troops heading west need more supplies. send general dubois' men to aid

row by row into the matrix. Then, to encipher this, we simply read off the columns to get:

TIDIE MRNME REOGO SANOW RSLTP EEEDO
SSSNU AHTUD BIENP GODAE PEIDE LNS

The scytale cipher is just like one of these. Note that the number of "rows" in your message is determined by the diameter of your stick and the size of your writing. Cracking them, as you may guess, is just a matter of systematic guess-and-check.

How to crack the simple matrix transposition ciphers:

1. Count how many letters are in the ciphertext (for this example, assume the ciphertext is 99 letters long)
2. Make all of the matrices that would fit such a length (e.g. 2x50, 3x33, 4x25, 5x20, 6x17, 7x15, 8x13, 9x11, 10x10). Use TWO of each size.
3. For each size matrix, write out the ciphertext across the rows on one copy. On the other copy, write out the ciphertext down the columns.
4. At each stage, see if you can find anything legible, reading perpendicular to how you put the ciphertext in.

A harder version of the matrix transposition cipher is the column-scrambled matrix transposition cipher. Just like the ones above, you find a matrix of suitable dimensions and write your text in row-by-row. If there are blank cells left, fill them in with a dummy character (sometimes an 'X'). However, before writing down the ciphertext from the columns, you first scramble the columns. This generates a new matrix of the same size. Now read off the text down the columns, as before. This is a harder cipher, but there is a systematic way to crack it.

How to crack the column-scrambled matrix transposition ciphers:

1. Count how many letters are in your ciphertext (for example, 75) and factor that number (75 =5*5*3).
   
   
2. Create all of the possible matrices to fit this ciphertext (in our case, 3x25, 5x15, 15x5, 25x3).
   
   
3. Write the ciphertext into these matrices down the columns.
   
   
4. For each of your matrices, consider all of the possible permutations of the columns (for n columns, there are n! possible rearrangements). In our case, we hope that the message was enciphered using one of the last two matrices (the 15x5 and the 25x3), since in those cases, we have only 6 and 120 possibilites to check (3! = 6, 5! = 120, 15! ~ 1.31x10^12, 25! ~ 1.55x10^25).
   
   
5. Rearrange each matrix to see if you get anything intelligible. Read the message off row-by-row. Note that this is much more easily done by a computer than by hand, but it is doable (for small matrices).

Material referenced from Infosecschool and Cornell University

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RSA Algorithm - Information Security: Cryptography BE [ Computer / IT / E&TC ]

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       Suppose, we want to do: We have a "piece of data" that we want to somehow "scramble" so nobody can learn what this data is, and we want to send this data over unsecure lines to the recipient. Upon receipt of this scrambled data, the recipient must be able to "unscramle" this data to its original shape. The important thing here is that we want to do this "scrambling/unscrambling" process without requiring usage of any secret keys that both the sender and the recipient must posses in order to scramble and descramble the data. This is why the method we are going to discuss here is called "Public Key Cryptography". There are several Public Key Cryptography algorithms in use today. The most popular is called RSA algorithm, and is named after the initials of its inventors: R for Rivest, S for Shamir, and A for Adelman. By the way, they were students when they invented this algorithm. This is their picture at the time. 

     So here is the summary of operations. Please continue reading below for the detailed explanation of how this is achieved. Let's say that your WEB Browser has a piece of data, say number 14 (we'll call it a Plain message and label it as P=14). and it wants to encrypt this Plain message first and then send it to the Server. Upon receipt of this encrypted message, the Server wants to decrypt it to its original value. Here is the summary of what transpires. Before any communication happens, the Server had calculated, in advance, its public (n =33 and k=7) and private (j=3) keys. Now, to initiate the transaction, the Browser sends this message to the server: Hey Server, please send me your public key. The Server obliges: Here it comes, it's n=33, k=7. After receiving the Server's public key, the Browser converts the Plain message P=14 into the Encrypted message E=20 and sends it to the Server. The Server receives this encrypted message E=20 and using its secret key j=3 (and publicly known key n=33) decrypts the E=20 message into its original Plain message P=14.

Now, let's look a bit more into the math behind all this. 

Section1. Generating Public and Private Keys
First, as we mentioned above, before any transmission happens, the Server had calculated its public and secret keys.  Here is how. 

1.1) pick two prime numbers, we'll pick p = 3 and q = 11
1.2) calculate n = p * q = 3 * 11 = 33
1.3) calculate z = ( p - 1 ) * ( q - 1 ) = ( 3 - 1 ) * ( 11 - 1 ) = 20
1.4) choose a prime number k, such that k is co-prime to z, i.e, z is not divisible by k. We have several choices for k: 7, 11, 13, 17, 19 (we cannot use 5, because 20 is divisible by 5). Let's pick k=7 (smaller k, "less math").
1.5) So, the numbers n = 33 and k = 7 become the Server's public key.
1.6) Now, still done in advance of any transmission, the Server has to calculate it's secret key. Here is how.
1.7) k * j = 1 ( mod z )
1.8) 7 * j = 1 ( mod 20 )
1.9) ( 7 * j ) / 20 = ?
 with the remainder of 1 (the "?" here means: "something, but don't wory about it"; we are only interested in the remainder). Since we selected (on purpose) to work with small numbers, we can easily conclude that 21 / 20 gives "something" with the remainder of 1. So, 7 * j = 21, and j = 3. This is our secret key. We MUST NOT give this key away.

    Now, after the Server has done the above preparatory calculations in advance, we can begin our message transmission from our Browser to the Server. First, the Browser requests from the Server, the Server's public key, which the Server obliges, i.e., it sends n=33 and k=7 back to the Browser.  Now, we said that the Browser has a Plain message P=14, and it wants to encrypt it, before sending it to the Server. Here is how the encryption happens on the Browser.

Section 2. Encrypting the message
Here is the encryption math that Browser executes.

2.1) P ^ k = E ( mod n ) 
"^" means "to the power of"
P is the Plain message we want to encrypt
n and k are Server's public key (see Section 1)
E is our Encrypted message we want to generate

After plugging in the values, this equation is solved as follows:
2.2) 14 ^ 7 = E ( mod 33 )
This equation in English says: raise 14 to the power of 7, divide this by 33, giving the remainder of E.
2.3) 105413504 / 33 = 3194348.606 (well, I lied when I said that this is "Pencil and Paper" method only. You might want to use a calculator here).
2.4) 3194348 * 33 = 10541348
2.5) E = 105413504 - 10541348 = 20

So, our Encrypted message is E=20.  This is now the value that the Browser is going to send to the Server. When the Server receives this message, it then proceeds to Decrypt it, as follows.

Section 3. Decrypting the Message
Here is the decryption math the Server executes to recover the original Plain text message which the Browser started with.

3.1) E ^ j = P ( mod n)
E is the Encrypted message just received
j is the Server's secret key
P is the Plain message we are trying to recover
n is Server's public key (well part of; remember that Server's public key was calculated in Section 1 as consisting of two numbers: n=33 and k=7).

After plugging in the values:
3.2) 20 ^ 3 = P ( mod 33 )
3.3) 8000 / 33 = ? with the remainder of P.  So to calculate this remainder, we do:
3.4) 8000 / 33 = 242.424242...
3.5) 242 * 33 = 7986
3.6) P = 8000 - 7986 = 14, which is exactly the Plain text message that the Browser started with!

Well that's about it. While we did not discuss the theory behind the formulae involved I hope that you got at least a basic idea of how the public key cryptography using the RSA algorithm works.

Section 4. "Cracking the Code"
The essential requirement of the Public Key Cryptography is that the public and secret keys are mathematically related, but this relationship must be made very hard to determine by an outsider.  As you saw in the preceeding text, everything starts with  p and q, from which we calculated n. The public key consists of two numbers: n and k, where k is calculated from z and z is calculated from p and q. The secret key j, was calculated from k and z and,  as we just stated,  k and z are calculated from p and q. It follows then, that j is also calculated from p and q,which proves that the public and private keys are mathematically related.  So, if an outsider wanted to find the secret key j, by only knowing n, he must break down n into the two prime numbers that were used to produce it (remember that n = p * q). Now, here is the real crux of the bisquit: Decomposing a very large n into p and q is really difficult to do. It is easy with the small numbers that we have used in our demonstration, but try, for example decomposing p into p and q when p has several hundred digits. 


                                                     

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Video Lectures

 RSA Algorithm with a solution

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RSA Algortihm explained 

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DNS Cache Poisoning - Information Security

      A very popular topic for discussion in "Information Security" :


 Download this whole article as PDF Guide : Download now
                                   
DNS Cache Poisoning


    What is exactly DNS Poisoning?.. to study this we would first require to know little bit about DNS i.e Domain Name System.Firstly, let us have a brief look at DNS  and then move to the main problem


What is Domain Name System?
  In the world of the Internet and TCP/IP, IP addresses are used to route packets from source to destination. A single IP address, for example 203.192.135.234, is not difficult to remember. But trying to learn or track thousands of these addresses, including which server/node is associated with each address, is a daunting task. So instead, we use domain names to refer to systems with which we want to communicate


 Let us take a real world example : 
  When you enter the "Google.com" into the address bar of your browser, the Google page appears. This is because your PC executed a process to resolve Google.com to an IP address. Only by having the IP address is a system able to initiate a session with another system across the Internet. 
   
  In simple terms what I mean to say is :


Whether you try 

   or you try :

both will deliver the same results ... if you try www.google.com then your browser resolves the appropriate ip address for the page by looking up into the DNS table which is just  like an index and then process your request and display the page on your browser.



   Now that we have a good idea how DNS is supposed to work, it’s time to look at how this process can be used to co-opt one or more DNS caches.


What is DNS Cache Poisoning?


    DNS cache poisoning consists of changing or adding records in the resolver caches, either on the client or  the server, so that a DNS query for a domain returns an IP address for an attacker’s domain instead of the intended domain. 


To demonstrate how this might work, let’s step through Figure below


Figure : DNS Cache Poisoning

Step 1: The resolver checks the resolver cache in the workstation’s memory to see if it contains an entry for Farpoint.companyA.com.


Step 2: Having found no entry in the resolver cache, the resolver sends a resolution request to the internal DNS server.


Step 3: When the DNS server receives the request, it first checks to see if it’s authoritative. In this case, it isn’t authoritative for companyA.com. The next action it takes is to check its local cache to see if an entry for Farpoint.companyA.com exists. It doesn’t. So in Step 4 the internal DNS server begins the process of iteratively querying external DNS servers until it either resolves the domain name or it reaches a point at which it’s clear that the domain name entry doesn’t exist.


Step 4: A request is sent to one of the Internet root servers. The root server returns the address of a server authoritative for the .COM Internet space.


Step 5: A request is sent to the authoritative server for .COM. The address of a DNS server authoritative for the companyA.com domain is returned.


Step 6: A request is sent to the authoritative server for companyA.com. This is identical to the standard process for an iterative query – with one exception. A cracker has decided to poison the internal DNS server’s cache. In order to intercept a query and return malicious information, the cracker must know the transaction ID. Once the transaction ID is known, the attacker’s DNS server can respond as the authoritative server for companyA.com.


    Although this would be a simple matter with older DNS software (e.g. BIND 4 and earlier), newer DNS systems have build-in safeguards. In our example, the transaction ID used to identify each query instance is randomized. But figuring out the transaction ID is not impossible. All that’s required is time. To slow the response of the real authoritative server, our cracker uses a botnet to initiate a Denial of Service (DoS) attack. While the authoritative server struggles to deal with the attack, the attacker’s DNS server has time to determine the transaction ID.
      Once the ID is determined, a query response is sent to the internal DNS server. But the IP address for Farpoint.companyA.com in the response is actually the IP address of the attacker’s site. The response is placed into the server’s cache.


Step 7: The rogue IP address for Farpoint is returned to the client resolver.


Step 8: An entry is made in the resolver cache, and a session is initiated with the attacker’s site. At this point, both the workstation’s cache and the internal DNS server’s cache are poisoned. Any workstation on the internal network requesting resolution of Farpoint.companyA.com will receive the rogue address listed in the internal DNS server’s cache. This continues until the entry is deleted.
    Another method used to poison a DNS cache is the use of a recursive query sent by the attacker. The query can force the target server to connect to the authoritative source of the domain in the query. Once connected, rogue information about one or more domains might be sent to the querying server and posted to the server’s cache.
    There are other methods attackers use to poison DNS caches, but the objective is the same. 
    
   Now we’ll explore the consequences of using a poisoned DNS cache


Potential Consequences of Cache Poisoning



Identity Theft
   Once an attacker gets you to his site, he’ll try to trick you into leaving behind information he can use to impersonate you. One way to do this in our first example is to create a site identical to the real Farpoint.companyA.com. When the user connects using the poisoned cache information, she might be fooled into entering information about herself through apparently legitimate requests for her name, social security number, address, etc.


Distribution of Malware
  Another of objective of attackers using cache poisoning is the automatic distribution of malware. Instead of releasing malicious code into the Internet and realizing random results, the use of rogue IP addresses to redirect unsuspecting users to the attacker’s site can be a more focused attack vector. Once a workstation initiates a session with the malicious site, malware is uploaded to the workstation without intervention by or the knowledge of the user.


Dissemination of False Information
   This aspect of pharming is useful to attackers who want to spread self-serving information about an organization. It’s also been used to manipulate stock prices in an attempt to realize a large profit.


Man-in-the-middle Attack
  In this attack type, the workstation initiates a session with the attacker’s server. The attacker’s server initiates a session with the actual target site. All information flowing between the workstation and the genuine site passes through and is intercepted by the cracker’s server. 
    There can be serious consequences when security is an afterthought during the configuration and deployment of DNS servers. The next section provides guidelines that can help prevent cache poisoning.






Explanation of DNS Cache Poisoning

Example of DNS Posioning Attack

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