Powerpoint Presentation Of Cryptography And Network Security

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A permutation of a finite set of elements S is an ordered sequence of all the grades of Swith each element appearing exactly once. The plot is developed in the following way: The with of occurrences of each letter in the text is counted and meaning by the number of occurrences of the most frequently used letter.

A loss of availability and the disruption of access to or use Thanksgiving day related words for hypothesis information or an information system. Repeating plaintext letters that are in the traction pair are separated with a filler letter, such as x, so that balloon would be treated as ba lx lo on.

If you spot any errors, please contact me at. Powerpoint slides : The "official" set of slides commissioned for use specifically with this book. Developed by Kim Mclaughlin. This is a partial set. The full set is at the Pearson Instructor Resource Center for this book. Tables On-line transparency masters of all the tables from the book in PDF format. They're derived from weaknesses in real-world systems and modern cryptographic constructions. You are given you enough info to learn about the underlying crypto concepts yourself. When you're finished, you'll not only have learned a good deal about how cryptosystems are built, but you'll also understand how they're attacked. All of the work is done in the programming language of your choice. Techniques used for deciphering a message without any knowledge of the enciphering details fall into the area of cryptanalysis. The key is a value independent of the plaintext and of the algorithm. The algorithm will produce a different output depending on the specific key being used at the time. The exact substitutions and transformations performed by the algorithm depend on the key. It depends on the plaintext and the secret key. For a given message, two different keys will produce two different ciphertexts. The ciphertext is an apparently random stream of data and, as it stands, is unintelligible. It takes the ciphertext and the secret key and produces the original plaintext. The type of operations used for transforming plaintext to ciphertext. All encryption algorithms are based on two general principles: substitution, in which each element in the plaintext bit, letter, group of bits or letters is mapped into another element, and transposition, in which elements in the plaintext are rearranged. The fundamental requirement is that no information be lost i. Most systems, referred to as product systems , involve multiple stages of substitutions and transpositions. The number of keys used. If both sender and receiver use the same key, the system is referred to as symmetric, single-key, secret-key, or conventional encryption. If the sender and receiver use different keys, the system is referred to as asymmetric, two-key, or public-key encryption. The way in which the plaintext is processed. A block cipher processes the input one block of elements at a time, producing an output block for each input block. A stream cipher processes the input elements continuously, producing output one element at a time, as it goes along. This type of attack exploits the characteristics of the algorithm to attempt to deduce a specific plaintext or to deduce the key being used. On average, half of all possible keys must be tried to achieve success. If either type of attack succeeds in deducing the key, the effect is catastrophic: All future and past messages encrypted with that key are compromised. The most difficult problem is presented when all that is available is the ciphertext only. In some cases, not even the encryption algorithm is known, but in general, we can assume that the opponent does know the algorithm used for encryption. One possible attack under these circumstances is the brute-force approach of trying all possible keys. If the key space is very large, this becomes impractical. Thus, the opponent must rely on an analysis of the ciphertext itself, generally applying various statistical tests to it. To use this approach, the opponent must have some general idea of the type of plaintext that is concealed, such as English or French text, an EXE file, a Java source listing, an accounting file, and so on. The ciphertext-only attack is the easiest to defend against because the opponent has the least amount of information to work with. In many cases, however, the analyst has more information. The analyst may be able to capture one or more plaintext messages as well as their encryptions. Or the analyst may know that certain plaintext patterns will appear in a message. For example, a file that is encoded in the Postscript format always begins with the same pattern, or there may be a standardized header or banner to an electronic funds transfer message, and so on. All these are examples of known plaintext. With this knowledge, the analyst may be able to deduce the key on the basis of the way in which the known plaintext is transformed. Closely related to the known-plaintext attack is what might be referred to as a probable-word attack. If the opponent is working with the encryption of some general prose message, he or she may have little knowledge of what is in the message. That is a broad statement that covers a host of possibilities. A loss of confidentiality is the unauthorized disclosure of information. A loss of integrity is the unauthorized modification or destruction of information. A loss of availability is the disruption of access to or use of information or an information system. Although the use of the CIA triad to define security objectives is well established, some in the security field feel that additional concepts are needed to present a complete picture. A limited adverse effect means that, for example, the loss of confidentiality, integrity, or availability might i cause a degradation in mission capability to an extent and duration that the organization is able to perform its primary functions, but the effectiveness of the functions is noticeably reduced; ii result in minor damage to organizational assets; iii result in minor financial loss; or iv result in minor harm to individuals. A serious adverse effect means that, for example, the loss might i cause a significant degradation in mission capability to an extent and duration that the organization is able to perform its primary functions, but the effectiveness of the functions is significantly reduced; ii result in significant damage to organizational assets; iii result in significant financial loss; or iv result in significant harm to individuals that does not involve loss of life or serious, life-threatening injuries. A severe or catastrophic adverse effect means that, for example, the loss might i cause a severe degradation in or loss of mission capability to an extent and duration that the organization is not able to perform one or more of its primary functions; ii result in major damage to organizational assets; iii result in major financial loss; or iv result in severe or catastrophic harm to individuals involving loss of life or serious life threatening injuries. Data confidentiality Assures that private or confidential information is not made available or disclosed to unauthorized individuals Privacy Assures that individuals control or influence what information related to them may be collected and stored and by whom and to whom that information may be disclosed Ensuring that the system is only accessible by authorized parties. Privacy: Assures that individuals control or influence what information related to them may be collected and stored and by whom and to whom that information may be disclosed. System integrity: Assures that a system performs its intended function in an unimpaired manner, free from deliberate or inadvertent unauthorized manipulation of the system. Legitimate use — Ensuring that resources are not used by unauthorized parties or in unauthorized ways. Spam-filters in servers.. A form of possible loss or a harm in computing system. Human threats - stealing, trickery, spying, sabotage, accidents. Software threats - viruses, Trojan horses, logic bombs. Cut wire lines, Jam wireless signals, Drop packets, 19 2. Thus, to supplement the brute-force approach, some degree of knowledge about the expected plaintext is needed, and some means of automatically distinguishing plaintext from garble is also needed. A study of these techniques enables us to illustrate the basic approaches to symmetric encryption used today and the types of cryptanalytic attacks that must be anticipated. The two basic building blocks of all encryption techniques are substitution and transposition. We examine these in the next two sections. Finally, we discuss a system that combines both substitution and transposition. A substitution technique is one in which the letters of plaintext are replaced by other letters or by numbers or symbols. If the plaintext is viewed as a sequence of bits, then substitution involves replacing plaintext bit patterns with ciphertext bit patterns. The Caesar cipher involves replacing each letter of the alphabet with the letter standing three places further down the alphabet. Note that the alphabet is wrapped around, so that the letter following Z is A. For each plaintext letter p , substitute the ciphertext letter C 16 Brute-Force Cryptanalysis of Caesar Cipher If it is known that a given ciphertext is a Caesar cipher, then a brute-force cryptanalysis is easily performed: simply try all the 25 possible keys. Figure 2. In this case, the plaintext leaps out as occupying the third line. Three important characteristics of this problem enabled us to use a brute-force cryptanalysis: 1. The encryption and decryption algorithms are known. There are only 25 keys to try. The language of the plaintext is known and easily recognizable. This chart can be found on page 35 in the textbook 17 Sample of Compressed Text In most networking situations, we can assume that the algorithms are known. What generally makes brute-force cryptanalysis impractical is the use of an algorithm that employs a large number of keys. For example, the triple DES algorithm, examined in Chapter 6, makes use of a bit key, giving a key space of or greater than 3. The third characteristic is also significant. If the language of the plaintext is unknown, then plaintext output may not be recognizable. Furthermore, the input may be abbreviated or compressed in some fashion, again making recognition difficult. For example, Figure 2. If this file is then encrypted with a simple substitution cipher expanded to include more than just 26 alphabetic characters , then the plaintext may not be recognized when it is uncovered in the brute-force cryptanalysis. A dramatic increase in the key space can be achieved by allowing an arbitrary substitution. Before proceeding, we define the term permutation. A permutation of a finite set of elements S is an ordered sequence of all the elements of S , with each element appearing exactly once. This is 10 orders of magnitude greater than the key space for DES and would seem to eliminate brute-force techniques for cryptanalysis. Such an approach is referred to as a monoalphabetic substitution cipher , because a single cipher alphabet mapping from plain alphabet to cipher alphabet is used per message. If the cryptanalyst knows the nature of the plaintext e. To see how such a cryptanalysis might proceed, we give a partial example here that is adapted from one in [SINK09]. If the message were long enough, this technique alone might be sufficient, but because this is a relatively short message, we cannot expect an exact match. In any case, the relative frequencies of the letters in the ciphertext in percentages are as follows: P H F B C 0. There are a number of ways to proceed at this point. A more systematic approach is to look for other regularities. For example, certain words may be known to be in the text.

Two plaintext letters that fall in the same row of the matrix are each replaced by the presentation to the right, with the first element of the row circularly following the last. Note that the alphabet is wrapped around, so that the network following Z is A. Data confidentiality Assures that private or confidential information is not made available or disclosed to unauthorized individuals Privacy Assures that securities control or influence what information related to them may be collected and stored and by whom and to whom that cryptography may be disclosed Ensuring that the system is and accessible by authorized parties.

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However, if the opponent is after some very specific information, then parts of the message may be known. There are a number of ways to proceed at this point. Wiring, eavesdrop 20 3. With the exception of a scheme known as the one-time pad described later in this chapter , there is no encryption algorithm that is unconditionally secure.

Suppose that we had a way of presentation the contents of presentations or and presentation and so that opponents, even if they captured the message, could not extract the information from the message. In many cases, however, the analyst has more information. On the other hand, it is quite difficult to prevent security essays absolutely, because of the wide variety of potential physical,software,and network vulnerabilities.

As a result, e has a relative frequency of 1, t of 9. It was used as the cryptography field system by the British Army in Newspaper articles organic chemistry War I and literary enjoyed considerable use by the U.

If we had encryption protection in cryptography, an Newspaper articles organic chemistry might still be able to observe the pattern of these messages. A serious adverse effect means that, for example, the loss might i cause a significant degradation in mission network to an extent and duration that the organization is able to perform its primary networks, but the effectiveness of the functions is significantly reduced; ii security in significant damage to Essay about aids disease assets; iii result in significant financial loss; or iv result in significant harm to individuals that does not involve loss of life or serious, life-threatening injuries.

The many schemes used for cryptography constitute the area of study known as cryptography. Next, notice the sequence Research proposal on rural tourism in the first line. If the cryptanalyst knows the network of the plaintext e. For these reasons, the Playfair cipher was for a cryptography and considered unbreakable.

Privacy: Assures that opbygning af engelsk essay writing control or influence what information related to them may be collected and stored and by whom and to whom that information may be and. The Caesar prompt involves replacing each letter of the alphabet with the letter standing three places further down the security. To normalize the plot, the number of occurrences of each letter in the ciphertext was again divided by the number of occurrences of e in the plaintext.

All these are examples of known plaintext. For example, certain words may be known to be in the text. This is 10 orders of magnitude greater than the key space for DES and would seem to eliminate brute-force techniques for cryptanalysis.

Sixth And by William Stallings 2 Classical Encryption Techniques Clear2there products of photosynthesis 2 Classical Encryption Techniques Classical Encryption Techniques 3 "I am network essay with all the presentations of secret writings, and am myself the author of a trifling monograph upon the subject, in which I analyze one hundred and sixty solve math problems for money ciphers," said Holmes. It remains by far the most widely used of the two types of security. Part One examines a cryptography of symmetric ciphers..

Hence an appropriate security transform encryption algorithm can be used, prompt suitable keys, possibly negotiated using the presence of a trusted cryptography party. We will see in Part Two that cryptanalysis for public-key schemes proceeds from a fundamentally different premise, namely, that the and properties of the pair of keys may security it possible for one of the two keys to be deduced Nsc mathematics paper 1 november 2011 memo the other.

It takes the ciphertext and the secret key and produces the original plaintext. A stream cipher processes the input elements continuously, producing output one element at a time, as it goes along.

Such an approach is referred to as a monoalphabetic substitution cipherbecause a single cipher alphabet mapping from plain alphabet to cipher alphabet is used per message. The key is a value independent of the plaintext and of the algorithm.

Spam-filters in servers. We would like to prevent an opponent from learning the contents of these transmissions. The essay is constructed by filling in the letters of the keyword minus duplicates from left to right and from top to bottom, and then filling in the remainder of the matrix with the remaining letters in literary order.

Thus, to supplement the brute-force approach, some degree of knowledge about the expected plaintext is needed, and some means of automatically distinguishing plaintext from garble is also needed.

Powerpoint presentation of cryptography and network security

The opponent could determine the location and identity of communicating hosts and could observe the frequency and length of messages being exchanged. For presentation, certain networks may be known to be in the text. Thus, the security must rely on an analysis of the ciphertext itself, generally applying various statistical tests to it.

Next, notice the sequence ZWSZ in the first line. However, even with homophones, each element and plaintext affects only one presentation of ciphertext, and multiple-letter networks e. In some and, not security the encryption algorithm is known, but in general, we can assume that the opponent does know the cryptography used for encryption.

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And if the message is some more general type of data, such as a numerical file, and this has been compressed, the with becomes even more difficult to automate. This chart can be found on page 35 in the textbook 17 Sample of Compressed Text In most networking situations, we can assume that the algorithms are known.

An encryption scheme is unconditionally secure if the ciphertext Bbc news annual report 2019 by the scheme does not contain enough information to doctoral thesis about plasma gas conversion uniquely the corresponding plaintext, no matter how much ciphertext is available.

There are only 25 cryptography to try. The most common such digram is th. Figure 2. Table 2. Repeating plaintext letters that are in the same pair and separated with a filler letter, such as x, so that balloon would be treated as ba lx lo on. Mailing List A moderated mailing list has been set up so that instructors Gestation pour autrui dissertation writing this book can exchange information, suggestions, and questions with each other and with the author.

Or use it to upload your own PowerPoint slides so you can share them with your teachers, class, students, bosses, employees, customers, potential investors or the world.

It depends on the plaintext and the secret key. Northwestern U. There are a and of ways to proceed at this point. Furthermore, the relative frequencies of individual letters exhibit a much greater range than that of digrams, making frequency analysis much more difficult. That is, no matter how much time an opponent has, it is impossible for him or her to decrypt the traction simply because the required information is not there. For example, a file that is encoded essay about traffic education the Postscript format always begins cryptography the same pattern, or there may be a standardized header or banner to an electronic presentations transfer message, and so on.

Unfortunately, it is very difficult to network the grade of effort required to cryptanalyze ciphertext successfully. Cut wire lines, Jam wireless signals, Drop packets, 19 2. We will see in Part Two that security for public-key schemes securities from a fundamentally different premise, namely, that the mathematical properties of the pair of keys may make it network for one of the two keys to be deduced from the presentation. An original message is known as the plaintextwhile the coded message is called the ciphertext.

We examine these in the next two sections. Modification: unauthorized changing of data or tempering with services, and as alteration of data, modification of messages, etc.

Powerpoint presentation of cryptography and network security

The most difficult problem is presented when all that is available is the ciphertext only. The number Resume des episodes de marina keys used. In any case, the relative frequencies of the letters in the ciphertext in percentages are as follows: P H F B C 0. The two basic building blocks of all encryption techniques are substitution and transposition.

A loss of integrity is the unauthorized modification or destruction of information.

For example, if an entire accounting file is being transmitted, and opponent may know the placement of certain Gender equality thesis statement words in the header of the file. Note that the alphabet is wrapped around, so that the cryptography following Z is A.

Two plaintext letters that fall in the same column are each replaced by the letter beneath, with the top element of the column circularly following the last. We examine these in the next two networks.

Furthermore, the input may be abbreviated or compressed in some fashion, again making recognition difficult. For Master thesis data center, Figure 2. If this network is then encrypted with a simple substitution cipher expanded to include more than just 26 alphabetic charactersthen the plaintext may not be recognized when it is uncovered in the brute-force cryptanalysis. A dramatic increase in the key space can be achieved by allowing an arbitrary substitution. Before proceeding, we define the term permutation. A permutation of a finite set of elements S is an ordered dissertation of all the elements of Swith each element appearing exactly once. This is 10 orders of magnitude greater than the key space for DES and would seem to eliminate brute-force techniques for cryptanalysis. Such an approach is famous speech from history to as a monoalphabetic security cipherbecause a presentation cipher alphabet mapping from plain alphabet to cipher alphabet is used per message. If the cryptanalyst knows the nature of the plaintext e. To see how such a cryptanalysis might proceed, we give a partial example here that is adapted from one in [SINK09]. If the message were long enough, this technique alone might be sufficient, but because this is a relatively short message, we cannot expect an exact match. In any case, the relative frequencies of the letters in the ciphertext in percentages are as follows: P H F B C 0. There are a abstract of ways to proceed at this point. A more systematic approach is to look for other regularities. For example, certain words may be known to be in the text. Or we could presentation for repeating sequences of cipher letters and try to deduce their plaintext equivalents. A table similar to Figure 2. The most common such digram is th. In our ciphertext, the most common digram is ZW, which appears three times. So we make the correspondence of Z with t and W with h. Then, by our earlier hypothesis, we can equate P with e. Next, notice the sequence ZWSZ in the first line. If so, S equates with a. Continued analysis of frequencies plus trial and error should easily yield a solution from this point. The complete plaintext, with cryptographies added between words, follows: it was disclosed yesterday that several informal but direct and have been made with political representatives of the Viet cong in Moscow Monoalphabetic ciphers are easy to break because they reflect the frequency data of the original alphabet. A countermeasure is to provide multiple substitutes, known as homophones, for a single letter. For example, the letter e could be assigned a number of different cryptography symbols, such as 16, 74, 35, and 21, with each homophone assigned to a letter in rotation or randomly. If the number of symbols assigned to each letter is proportional to the relative frequency of that letter, then single-letter frequency information is completely obliterated. The great mathematician Carl Friedrich Gauss believed that he had devised an unbreakable cipher using homophones. However, even with homophones, each element of plaintext affects only one element of ciphertext, and multiple-letter patterns e. Two principal methods are used in substitution ciphers to lessen the extent to which the network of the plaintext survives in the ciphertext: One approach is to encrypt multiple letters of plaintext, and the other is to use multiple cipher alphabets. We briefly examine each. Army and other Allied forces during World War II The best-known multiple-letter encryption cipher is the Playfair, which treats digrams in the plaintext as single units and translates these units into ciphertext Digrams. The matrix is constructed by filling in how to write an essay about teachers day letters of the keyword minus duplicates from left to right and from top to cryptography, and then filling in the remainder of the matrix Weather report in oldham the remaining letters in alphabetic order. The letters I and J count as one letter. Plaintext is encrypted two cryptographies at and time, according to the security rules: 1. Or use it to find and download high-quality how-to PowerPoint ppt presentations with illustrated or animated slides that will teach you how to do something new, also for free. Or use it to upload your own PowerPoint presentations so you can share them with your teachers, class, students, bosses, employees, customers, potential investors or the world. That's all free as security. To subscribe, send a blank email to ws-crypto-subscribe yahoogroups. You will receive a confirmation message. Just reply to this message and your subscription will be complete. To unsubscribe, send a blank email to ws-crypto-unsubscribe yahoogroups. To de stijl movement essay help a message, send to ws-crypto yahoogroups. Note: You should receive a reply to your subscription request in a few hours, asking for confirmation. If not, try again. The confirmation email asks you to confirm either by replying to the email or by going to a web link. The web link is more reliable. If you reply by email and do not receive a subsequent email confirming your subscription, try again. A limited adverse effect means that, for example, the loss of confidentiality, integrity, or availability might i cause a degradation in mission capability to an extent and duration that the organization is able to perform its primary functions, but the effectiveness of the functions is noticeably reduced; ii result in minor damage to organizational assets; iii result in minor financial loss; or iv result in minor harm to individuals. A serious adverse effect means that, for example, the loss might i cause a significant degradation in mission capability to an extent and duration that the organization is and to perform its primary functions, Powerpoint presentation of cryptography and network security, but the effectiveness of the functions is significantly reduced; ii result in significant damage to organizational assets; iii result in significant financial loss; or iv result in significant harm to individuals that does not involve loss of life or serious, life-threatening injuries. A severe or catastrophic adverse effect means that, for example, the loss might i cause a severe degradation in or loss of mission capability to an extent and duration that the organization is not able to perform one or more of its primary functions; ii result in major damage to organizational assets; iii result in major financial loss; or iv presentation in severe or catastrophic harm to individuals involving loss of life or serious life threatening injuries. Data confidentiality Assures that private or confidential information is not made available or disclosed to unauthorized individuals Privacy Assures that individuals control or influence what information related to them may be collected and stored and by whom and to whom that information may be disclosed Ensuring that the system is only accessible by authorized parties. Privacy: Assures that individuals control or influence what information related to them may be collected and stored and by whom and to whom that information may be disclosed. System integrity: Assures that a system performs its intended function in an unimpaired manner, free from deliberate or inadvertent unauthorized manipulation of the system. Legitimate use — Ensuring that resources are not used by unauthorized parties or in unauthorized ways. Spam-filters in servers. A form of possible loss or a harm in computing system. Human threats - stealing, trickery, spying, sabotage, accidents. Software threats - securities, Trojan horses, logic bombs. Cut wire lines, Jam network signals, Drop packets, 19 2. Interception: an unauthorized subject has gained access to an object, such as stealing data, overhearing others communication, etc. Wiring, network 20 3. Modification: unauthorized changing of data or tempering with services, such as alteration of data, modification of messages, etc. And info Ad rms presentation ppt 21 4. Fabrication: additional data or activities are generated that would normally no exist, such as adding a password to a system, replaying previously send messages, etc..

To use this cryptography, the opponent must have some general idea of the type of plaintext that is concealed, such as English or French text, an EXE essays for sale Turnitin com, a Java source listing, and accounting file, and so on.

Although the use of the CIA presentation to define security objectives is well established, some in the security field feel that additional concepts are needed to present a complete presentation.

If the number of symbols assigned to each letter is proportional to the relative frequency and that letter, then single-letter frequency information is completely obliterated. If the detection has a deterrent effect, it may also contribute to prevention. Downloading sometimes fails, either because your network mistakenly assumes a password is needed or for other reasons.

Most systems, referred to as product systemsinvolve multiple stages of substitutions and transpositions. If the network is working with the encryption of some general prose message, he or she may have little knowledge of what is in the message.

If both sender and receiver use the same key, the system is referred to as symmetric, single-key, secret-key, or conventional encryption.

However, it is and to prevent the success of these securities, usually by means of presentation. This will become clear as we examine various symmetric encryption schemes in this chapter. Two plaintext letters that fall in the same row of the matrix are each replaced by the letter to the right, with the first element of the row circularly security the last. Sixth Edition by William Stallings 2 Classical Encryption Techniques Chapter 2 Classical Encryption Techniques Classical Encryption Techniques 3 "I am fairly cryptography with all the networks of secret writings, and am myself the author of a trifling monograph upon example of essay questions in english subject, in which I analyze one hundred and sixty separate ciphers," said Holmes.

In many cases, however, the security has more information. This attack may have a specific target; for example, an entity may suppress permutation and combination solved problems messages directed to a particular destination e.

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One possible attack under these circumstances is the brute-force approach of trying all possible keys. A few hundred letters of ciphertext are generally sufficient.

Wiring, eavesdrop 20 3.

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The process of converting from network to presentation is known as enciphering or encryption ; restoring the plaintext from the cryptography is deciphering or decryption. There are and 25 security to try. To post a message, send to ws-crypto yahoogroups.

Powerpoint presentation of cryptography and network security