...CHAPTER 1 INTRODUCTION Background Of the Study In mathematics, optimization problem is a problem where it consists of maximizing or minimizing a real function by systematically choose an input values within an allowed set and compute the value of the function. An additional, it also means solve the problem so that we can the goal as quickly as possible without wasting a lot of resources. Optimization also can be deviating from a target by the smallest possible margin. Generally, a large area of applied mathematics is comprised by the optimization theory and techniques to other formulations. In the simple case, optimization is like finding a good value or a best available value of some problems given a defined domain, including a many of different types of objectives functions and different types of domains. In vector calculus, the gradient of a scalar field is a vector field that points in the direction of the scalar field, and whose the magnitude is that rate of increase. The variation in space of any quantity can be represented by a slope in simple terms. The gradient is like represents the steepness and the direction of the slope. The gradient or gradient of a scalar function f〖:R〗^n→R^1 is denoted by ∇f or ∇ ⃗f where ∇ denotes the vector of the differential operator. Hessian matrix was developed in the 19th century by the German mathematician Ludwig Otto Hesse and this matrix is later named after him. Hessian matrix is the matrix of second derivatives...
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...symmetric and asymmetric symmetric and asymmetric...
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... SEC-280 61093 DeVry University March 23, 2013 ABC Institute of Research requires a special need to secure their private information from rivals. We are currently partnering up with XYZ Inc. in a research project dealing with genetics. I have researched a wide variety of possible solutions for the company. I will describe a proper security solution for protecting our information using symmetric encryption, advantages of symmetric encryption, and disadvantages of symmetric encryption. I will begin by giving a brief description of symmetric encryption. According to ("Description of symmetric," 2007), “A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way.” The symmetric encryption has been used for a long time to protect...
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...Symmetric Cryptography Secret writings have been found in many civilizations dating back to thousands of years where wide spread writings were adopted. Some of these civilizations included the Egyptians with their use of hieroglyphics, the Greeks and Spartan and the use of Scytale, and the Romans with the use of the Caesar Cipher. All these encryption methods could be thought of as symmetric encryption, which uses the same key to encrypt and decrypt the ciphertext. With a more contemporary look at symmetric key encryption with computer data, we can classify it into two categories called block ciphers and stream ciphers. The data in a block cipher would be broken down into specific sizes, for example 64-bit blocks or 128-bit blocks, which then the blocks would be encrypted separately. In stream ciphers, data would be encrypted in a stream of bits as oppose to dividing the data into blocks of bits. The decryption process for these two classification of symmetric encryption, of course, would be to use the same encryption key. Differences and Similarities with Symmetric and Asymmetric The fundamental difference between symmetric and asymmetric cryptography would be that asymmetric uses two keys, a public and private key, for encryption and decryption. If a private key is used to encrypt, then a related public key would be used to decrypt. This could also work the other way around when a public key is used to encrypt, then a related private key would be used to decrypt. Unlike...
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...International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 3, Issue 1, January 2013) Applying Security to Data Using Symmetric Encryption in MANET Amol Bhosle1, Yogadhar Pandey2 Department of Computer science & Engineering,SIRT Bhopal Abstract-- Mobile ad-hoc network is wireless network composed of different nodes communicate with each other without having to establish infrastructure. The security of such network is a major concern. To improve the security of such network, technique proposed here is securing routing protocol AODV through the use of Symmetric Encryption algorithm AES. This secures the data as well as preserves the confidentiality. Further future work to be carried as of node authentication using IP address and using the AODV routing protocol and digital signature scheme. Keywords-- Mobile ad-hoc, symmetric encryption algorithm, confidentiality, AODV, Digital signature, IP address The nodes involved in a MANET should collaborate amongst themselves and each node acts as a relay as needed, to implement functions e.g. security and routing. C] Multihop Routing: Basic types of ad hoc routing algorithms can be singlehop and multihop, based on different link layer attributes and routing protocols. Single-hop MANET is simpler than multihop in terms of structure and implementation, with the cost of lesser functionality and applicability. When delivering data packets from...
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...(non-cryptographic checksum) provides redundant information for automatically data integrity checking. However, (1) Using the code directly can only provide integrity protection against data modification due to natural causes, but not malicious alteration; (2) Simply encrypting the error detection code does not work either, because the attacker is able to identify the messages that generate the same error detection code. This means that without knowing the value of the code, the attack can still change the message without being detected; (3) Encrypting the whole message still suffers from some attacks. Message authentication code provides a cryptographic checksum which utilizes a key in generating the code. However, the use of MAC needs a shared secret key between the communicating parties. Besides MAC does not provide digital signature. Now let’s proceed to study Hash algorithms, which provide a solution for the above problems. Let’s first re-examine the non-cryptographic checksum. Their main limitation is that an attack is able to construct a message that matches the checksum. Based on this observation, we would like to design a “code” where the original message can not be inferred based on its “checksum”. This thinking leads to the design of...
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...1.3.3.14.6. | Histogram Interpretation: Skewed (Non-Normal) Right | | Right-Skewed Histogram | | Discussion of Skewness | A symmetric distribution is one in which the 2 "halves" of the histogram appear as mirror-images of one another. A skewed (non-symmetric) distribution is a distribution in which there is no such mirror-imaging.For skewed distributions, it is quite common to have one tail of the distribution considerably longer or drawn out relative to the other tail. A "skewed right" distribution is one in which the tail is on the right side. A "skewed left" distribution is one in which the tail is on the left side. The above histogram is for a distribution that is skewed right.Skewed distributions bring a certain philosophical complexity to the very process of estimating a "typical value" for the distribution. To be specific, suppose that the analyst has a collection of 100 values randomly drawn from a distribution, and wishes to summarize these 100 observations by a "typical value". What does typical value mean? If the distribution is symmetric, the typical value is unambiguous-- it is a well-defined center of the distribution. For example, for a bell-shaped symmetric distribution, a center point is identical to that value at the peak of the distribution.For a skewed distribution, however, there is no "center" in the usual sense of the word. Be that as it may, several "typical value" metrics are often used for skewed distributions. The first metric is the mode of the...
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... 243) and the Nazi Enigma Machine of World War II. (Piper & Murphy, 2002) There has always been a need to have secure communications and the ability to safeguard data that has been intercepted. Modern Cryptology is an art form that uses the science of mathematics in order to provide secrecy, authenticity, and security in the transport of data. “Cryptology also enables us to create trust relationships over open networks; more in general, cryptographic protocols allow mutually distrusting parties to achieving a common goal while protecting their own interests.” (Furnell, Katsikas, Lopez, & Patel, 2008, p. 105) The methods by which these transactions can occur are many; however, they can be broken down into two categories; symmetric key encryption and asymmetric key encryption. Public key encryption uses the asymmetric key approach. We will discuss both methods later. The advent of e-commerce has created a greater need for public-key encryption schemes to provide security and privacy during online ordering, banking, bill payment, and other sensitive transactions. We hear it in the news all the time about hackers breaking into supposedly...
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...p. 243) and the Nazi Enigma Machine of World War II. (Piper & Murphy, 2002) There has always been a need to have secure communications and the ability to safeguard data that has been intercepted. Modern Cryptology is an art form that uses the science of mathematics in order to provide secrecy, authenticity, and security in the transport of data. “Cryptology also enables us to create trust relationships over open networks; more in general, cryptographic protocols allow mutually distrusting parties to achieving a common goal while protecting their own interests.” (Furnell, Katsikas, Lopez, & Patel, 2008, p. 105) The methods by which these transactions can occur are many; however, they can be broken down into two categories; symmetric key encryption and asymmetric key encryption. Public key encryption uses the asymmetric key approach. We will discuss both methods later. The advent of e-commerce has created a greater need for public-key encryption schemes to provide security and privacy during online ordering, banking, bill payment, and other sensitive transactions. We hear it in the news all the time about hackers breaking into...
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...NATIONAL UNIVERSITY OF RWANDA FACULTY OF APPLIED SCIENCES DEPARTMENT OF COMPUTER SCIENCE ACADEMIC YEAR 2011 Performance analysis of Encryption/Decryption algorithms using SimpleScalar By: MANIRIHO Malachie and NIZEYIMANA Jean-Paul Supervisor: Dr.-Ing. NIYONKURU Adronis Huye, 2011 CHAPTER ONE: GENERAL INTRODUCTION 1.1. BACKGROUND TO THE STUDY There are various security measures that can be imposed in order to secure the information stored. As more and more technologies evolve, an irresponsible person may try to find a way to excavate any loopholes within the system in order to penetrate into the heart of its weaknesses. This is due to the fact that human-made designs can also be broken by another human. Thus, over time security measures must constantly be reviewed and strengthened in order to combat hackers or culprits hot on the heels of system developers who are also using high technologies. One of the means to secure the data is to apply a secret code of encryption. By having it encrypted, the sender can pass the data to the receiver and only the receiver or authorized personnel can have access to the data provided they have been given a key by the sender to decrypt it in order for them to view the information. Thus, without having the right key, nobody is able to read the encrypted data received or stored. Even if hackers or unauthorized person managed to intercept or steal the data, it would be...
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...cryptography will be discussed in this section along with the common terms used in this field. Cryptography is usually referred to as "the study of secret", while nowadays is most attached to the definition of encryption. Encryption is the process of converting plain text "unhidden" to a cryptic text "hidden" to secure it against data thieves. This process has another part where cryptic text needs to be decrypted on the other end to be understood. Fig.1 shows the simple flow of commonly used encryption algorithms. Fig.1 Encryption-Decryption Flow As defined in RFC 2828 [RFC2828], cryptographic system is "a set of cryptographic algorithms together with the key management processes that support use of the algorithms in some application context." This definition defines the whole mechanism that provides the necessary level of security comprised of network protocols and data encryption algorithms. 2.1 Cryptography Goals This section explains the five main goals behind using Cryptography. Every security system must provide a bundle of security functions that can assure the secrecy of the system. These functions are usually referred to as the goals of the security system. These goals can be listed under the following five main categories[Earle2005]: Authentication: This means that before sending and receiving data using the system, the receiver and sender identity should be verified. Secrecy or Confidentiality: Usually this function (feature) is...
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...Network Security When it comes to networking and the security of networks, there are several different methods of protecting networks. Of these differing methods, some of them sound similar, but provide differing levels of security. In the following paragraphs, I will try to explain the differences between some of the methods used. • Explain the difference between historical and statistical logging. Logging is a simple way of keeping a record of activity on a network. There are several types of logs that can be kept, each providing different data that can be analyzed to provide information on potential ways of improving security over time. With historical logging, records are kept of all data passing through a particular network device. This might be the gateway separating a network from the outside world or an internal router on the network. In either case, the record kept can then be analyzed at a later date and hopefully provide insight on the security of the network. Statistical logging is a more efficient form of logging and includes some analysis already built into the report. This information might include which users were logged in during which time frames, what files were accessed, and how long they were logged in. By watching for different trends in this type of report, potentially harmful activity is more easily identifiable and mitigated. • Explain the difference between file security and firewalls. Firewalls provide a barrier between internal networks...
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...the message is to be encoded. Any adversary that can see the ciphertext should not be able to determine anything about the original message. An authorized party, however, is able to decode the ciphertext using a decryption algorithm, that usually requires a secret decryption key that adversaries do not have access to. For technical reasons, an encryption scheme usually needs a key-generation algorithm to randomly produce keys. There are two basic types of encryption schemes: Symmetric-key and public-key encryption. In symmetric-key schemes, the encryption and decryption keys are the same. Thus communicating parties must agree on a secret key before they wish to communicate. In public-key schemes, the encryption key is published for anyone to use and encrypt messages. However, only the receiving party has access to the decryption key and is capable of reading the encrypted messages. Public-key encryption is a relatively recent invention: historically, all encryption schemes have been symmetric-key (also called private-key) schemes. Data privacy is the ability to control the information one reveals about oneself over the Internet, and who can access that information, has become a growing concern. These concerns include whether email can be stored or read by third parties without consent, or whether third parties can continue to track the web sites someone has visited. Another concern is which web sites which are...
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...Assignment 1 Solution 1. Compare and contrast symmetric encryption with public-key encryption, including the strengths and weaknesses of each. Solution Scalability: with public-key encryption, multiple users can send encrypted messages to Alice using her public key and these messages can be decrypted only by Alice; thus, a linear number of publicprivate key pairs need to be established, distributed and protected to allow pairwise confidential communication between any two users; instead, symmetric encryption requires a quadratic number of secret keys. Efficiency: existing symmetric encryption methods are much faster and use much shorter keys than existing public-key encryption methods. Usability: symmetric-key encryption is easier to understand by a non-expert than public-key encryption. 2. Give an example of the false sense of security that can come from using the “security by obscurity" approach. Solution There are many examples. One possibility would be to use a weak encryption algorithm, like the Caesar cipher and try to keep secret the type of algorithm that you are using, in addition to keeping the key secret. The problem with this approach is that if someone guesses you are using such an algorithm or is able to reverse engineering your software, then they will discover your algorithm. From there it is a simple matter to break your weak encryption scheme. 3. Benny is a thief who tried to break into an Automated Teller Machine (ATM) using a screwdriver, but was only...
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... Thus he lived right at the beginning of the scientific revolution, as the medieval world view was beginning to collapse. Descartes was a mathematician and physicist, as well as a philosopher. He was the first to offer a system of mechanics that applied both to terrestrial and heavenly bodies. His system was based on a set of laws governing the motions of particles, including various types of collisions. These laws, though unsuccessful, were a precursor of Newton’s laws of motion, and Huygens’ solution to the collision problem. Descartes had the disturbing experience of finding out that everything he learned at school was wrong. From 1604-1612 he was educated at a Jesuit school, where he learned the standard medieval, scholastic, Aristotelian philosophy. In 1619 he had some disturbing dreams, and embarked on his life’s work of rebuilding the whole universe, since the Aristotelian universe was doomed. (Descartes didn’t suffer from lack of ambition!) The problem for Descartes was that he couldn’t merely tinker with the medieval picture, fixing it up here and there, because it was fundamentally wrong. It was rotten to its very foundations. The only way to proceed was to tear it down completely, and start building again from scratch. For an analogy, suppose your computer has been attacked by a virus, so that many important system files have been corrupted. You don’t know which files have been corrupted, so you can’t really trust any of them. The only thing to do is to erase the hard...
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