Cryptography And Network Security Notes In PdfBy Eliot P. In and pdf 25.05.2021 at 17:57 4 min read
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- CS8792 Cryptography And Network Security Notes CNS Notes CSE 7th Sem Anna University
- Cryptography and Network Security - CS8792, CS6701
- Applied Cryptography and Network Security
- Cryptography And Network Security - CNS Study Materials
Introduction to Modern Cryptography.
The 34 papers presented in this volume were carefully reviewed and selected from submissions. The topics focus on innovative research and current developments that advance the areas of applied cryptography, security analysis, cyber security and privacy, data and server security. Skip to main content Skip to table of contents.
CS8792 Cryptography And Network Security Notes CNS Notes CSE 7th Sem Anna University
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WordPress Shortcode. Published in: Engineering. Full Name Comment goes here. Are you sure you want to Yes No. Show More. No Downloads. Views Total views. Actions Shares. No notes for slide. However, for our purposes in this chapter, an understanding of the OSI protocol architecture is not required.
For our purposes, the OSI security architecture provides a useful, if abstract, overview of many of the concepts.. The OSI security architecture focuses on security attacks, mechanisms, and services. These can be defined briefly as follows: 1.
Security attack — Any action that compromises the security of information owned by an organization. Security mechanism — A mechanism that is designed to detect, prevent or recover from a security attack.
Security service — A service that enhances the security of the data processing systems and the information transfers of an organization. The services are intended to counter security attacks and they make use of one or more security mechanisms to provide the service. An attack, thus, can be passive or active. PassiveAttacks: The main goal of a passive attack is to obtain unauthorized access to the information.
For example, actions such as intercepting and eavesdropping on the communication channel can be regarded as passive attack. These actions are passive in nature, as they neither affect information nor disrupt the communication channel. A passive attack is often seen as stealing information. The only difference in stealing physical goods and stealing information is that theft of data still leaves the owner in possession of that data.
Passive information attack is thus more dangerous than stealing of goods, as information theft may go unnoticed by the owner.
Cryptography provides many tools and techniques for implementing cryptosystems capable of preventing most of the attacks described above. AssumptionsofAttacker: Let us see the prevailing environment around cryptosystems followed by the types of attacks employed to break these systems CryptographicAttacks: The basic intention of an attacker is to break a cryptosystem and to find the plaintext from the ciphertext.
To obtain the plaintext, the attacker only needs to find out the secret decryption key, as the algorithm is already in public domain. Hence, he applies maximum effort towards finding out the secret key used in the cryptosystem. Once the attacker is able to determine the key, the attacked system is considered as broken or compromised. He does not have access to corresponding plaintext. COA is said to be successful when the corresponding plaintext can be determined from a given set of ciphertext.
Occasionally, the encryption key can be determined from this attack. Modern cryptosystems are guarded against ciphertext-only attacks. The task is to decrypt the rest of the ciphertext using this information.
This may be done by determining the key or via some other method. The best example of this attack is linear cryptanalysis against block ciphers. So he has the ciphertext-plaintext pair of his choice.
This simplifies his task of 3. An example of this attack is differential cryptanalysis applied against block ciphers as well as hash functions. A popular public key cryptosystem, RSA is also vulnerable to chosen-plaintext attacks. In simplest method of this attack, attacker builds a dictionary of ciphertexts and corresponding plaintexts that he has learnt over a period of time.
In future, when an attacker gets the ciphertext, he refers the dictionary to find the corresponding plaintext. The attacker knows the ciphertext and the algorithm, now he attempts all the keys one by one for decryption. The time to complete the attack would be very high if the key is long. It is used against the cryptographic hash function. When students in a class are asked about their birthdays, the answer is one of the possible dates.
Let us assume the first student's birthdate is 3rd Aug. Then to find the next student whose birthdate is 3rd Aug, we need to enquire 1. Similarly, if the hash function produces 64 bit hash values, the possible hash values are 1. By repeatedly evaluating the function for different inputs, the same output is expected to be obtained after about 5.
If the attacker is able to find two different inputs that give the same hash value, it is a collision and that hash function is said to be broken. Instead, it is launched to exploit the weakness in physical implementation of the cryptosystem. By measuring such timings, it is be possible to know about a particular computation the processor is carrying out.
For example, if the encryption takes a longer time, it indicates that the secret key is long. Let us now see the possible goals intended to be fulfilled by cryptography. Confidentiality: Confidentiality is the fundamental security service provided by cryptography.
It is a security service that keeps the information from an unauthorized person. It is sometimes referred to as privacy or secrecy. Confidentiality can be achieved through numerous means starting from physical securing to the use of mathematical algorithms for data encryption.
Data Integrity: It is security service that deals with identifying any alteration to the data. The data may get modified by an unauthorized entity intentionally or accidently. Integrity service confirms that whether data is intact or not since it was last created, transmitted, or stored by an authorized user.
Data integrity cannot prevent the alteration of data, but provides a means for detecting whether data has been manipulated in an unauthorized manner. Authentication: Authentication provides the identification of the originator. It confirms to the receiver that the data received has been sent only by an identified and verified sender.
Non-repudiation: It is a security service that ensures that an entity cannot refuse the ownership of a previous commitment or an action. It is an assurance that the original creator of the data cannot deny the creation or transmission of the said data to a recipient or third party. Non-repudiation is a property that is most desirable in situations where there are chances of a dispute over the exchange of data.
For example, once an order is placed electronically, a purchaser cannot deny the purchase order, if non-repudiation service was enabled in this transaction.
One of the most specific security mechanisms in use is cryptographic techniques. Encryption or encryption-like 5. Some of the mechanisms are: A. Encipherment The use of mathematical algorithms to transform data into a form that is not readily intelligible.
The transformation and subsequent recovery of the data depend on an algorithm and zero or more encryption keys. Digital Signature Data appended to, or a cryptographic transformation of, a data unit that allows a recipient of the data unit to prove the source and integrity of the data unit and protect against forgery e.
Access Control A variety of mechanisms that enforce access rights to resources. Data Integrity A variety of mechanisms used to assure the integrity of a data unit or stream of data units. Authentication Exchange A mechanism intended to ensure the identity of an entity by means of information exchange. Traffic Padding The insertion of bits into gaps in a data stream to frustrate traffic analysis attempts. Routing Control Enables selection of particular physically secure routes for certain data and allows routing changes, especially when abreach of security is suspected.
Cryptosystems: A cryptosystem is an implementation of cryptographic techniques and their accompanying infrastructure to provide information security services.
A cryptosystem is also referred to as a cipher system.
Cryptography and Network Security - CS8792, CS6701
Introducing Textbook Solutions. If you need any solutions manual, you can send email with your own title to download it Cryptography and network security principles and practice 7th pdf. Get step-by-step explanations, verified by experts. In any, such sequence of five consecutive integers, beginning with an odd. View PracticeSolutions-Crypto7e.
Computer and Network Security by Avinash Kak. Computer and Network Security by Avinash Kak Think of these lecture notes as a living textbook that strives to strike a balance between the systems-oriented issues and the cryptographic issues. Without the latter, many aspects of the former cannot be fully comprehended, and, without the former, the latter are too dry to appreciate. On the other hand, when I teach the systems portion of the course, I spend quite a bit of time demonstrating the issues on my Linux laptop, again in the manner described in these lecture notes. These lecture notes are intended as much for showing in class in the form of slides as they are for focused reading by the students on their own. When used as slides, these serve as backdrop to the explanations provided on the chalkboard or through demonstrations on a computer.
Applied Cryptography and Network Security
Cryptography will continue to play important roles in developing of new security solutions which will be in great demand with the advent of high-speed next-generation communication systems and networks. This book discusses some of the critical security challenges faced by today's computing world and provides insights to possible mechanisms to defend against these attacks. The book contains sixteen chapters which deal with security and privacy issues in computing and communication networks, quantum cryptography and the evolutionary concepts of cryptography and their applications like chaos-based cryptography and DNA cryptography.
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Cryptography And Network Security - CNS Study Materials
Download Text book 5th edition. Download Modern cryptography. Download An introduction to cryptography. Download Applied Cryptography-Schneier. Download Question Bank 2 marks. Download Chapter 1 ppt.
Follow us on FB — Smartzworld. A1: Study of secret writing is called Cryptography. Crypto meaning secret and graphy means writing. The process is concerned with developing algorithms. It has the following charcteristis.
Computer-based Symmetric Key Cryptographic Algorithms: Algorithm Types and Modes,. An overview of Symmetric Key Cryptography, DES, International Data.
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Коммандер послал ее жениха, преподавателя, с заданием от АНБ и даже не потрудился сообщить директору о самом серьезном кризисе в истории агентства. - Вы не поставили в известность Лиланда Фонтейна. Терпение Стратмора иссякло. Он взорвался: - Сьюзан, выслушай. Я вызвал тебя сюда, потому что мне нужен союзник, а не следователь.
Иными словами, СЦР представляла собой оценочную стоимость вскрытия ТРАНСТЕКСТОМ одного шифра.
Глаза ее были полны слез. - Прости меня, Дэвид, - прошептала. - Я… я не могу. Дэвид даже вздрогнул.
Чем быстрее мы внесем изменение в программу, тем легче будет все остальное. У нас нет гарантий, что Дэвид найдет вторую копию.
И снова постаралась держаться с подчеркнутым безразличием. - Он поздравил меня с обнаружением черного хода в Попрыгунчике, - продолжал Хейл. - И назвал это победой в борьбе за личные права граждан всего мира. Ты должна признать, Сьюзан, что этот черный ход был придуман для того, чтобы ввести мир в заблуждение и преспокойно читать электронную почту. По мне, так поделом Стратмору.