Download Cryptography and Network Security: Definitions and Concepts and more Exams Biology in PDF only on Docsity!
CRYPTOGRAPHY AND NETWORK
SECURITY WITH COMPLETE
SOLUTIONS
Cryptography - answer The art or science that encompasses the principles and methods of transforming an intelligible message into one that is unintelligible, and then retransforming that message back to its original form. Network Security - answer Measures to protect data during their transmission The 3 OSI Security Architecture - answer 1. Security Attacks
- Security Services
- Security Mechanisms Security Attacks - answer Any action that compromises the security of information owned by an organization. 2 categories of Security Attacks - answer 1. Passive Attacks
- Active Attacks
Passive Attacks - answer Attempts to learn or make use of information from the system but do not affect system resources. It involves eavesdropping or monitoring data transmission. 2 types of Passive Attacks - answer 1. Release of Message Contents
- Traffic Analysis Release of Message Contents - answer Trying to access or reveal the secret content with a message Traffic Analysis - answer Involves studying data transmission patterns to uncover the location, identity of communicating hosts, and message frequency and length. This helps guess the nature of communication without accessing message content Active Attacks - answer Attempts to alter system resources or affect their operation. 4 different types of Active Attacks - answer 1. Masquerade
- Replay
- Modification of messages
- Denial of service
Active: Prevention is challenging due to various vulnerabilities, so focus is on detection and recovery Awareness of Parties - answer Passive: Usually go unnoticed by both sender and receiver. Active: The sender or receiver may notice unusual activity, delays, or disruptions, making them aware of the attack. Variability - answer Passive: Have a consistent pattern of eavesdropping or monitoring Active: Take various forms, including physical, software, or network based methods. Effect on Data - answer Passive: Aim to obtain information without altering it. Active: Can alter, destroy, or disrupt data, affecting its integrity and availability. Preventive Measures - answer Passive: Encryption and secure communication protocols. Active: Firewalls, intrusion detection systems, and security policies. Security Services - answer A service that is provided by a protocol layer of communicating open systems and that
ensures adequate security of the systems or of data transfers. A processing or communication service that enhances the security of the data processing systems and the information transfers of an organization. 5 categories of Security Service - answer 1. Authentication
- Access Control
- Data Confidentiality
- Data Integrity
- Nonrepudiation Authentication - answer The assurance that the communicating entity is the one that it claims to be. 2 categories of Authentication - answer 1. Peer Entity Authentication
- Data-Origin Authentication Peer Entity Authentication - answer It used in association with a logical connection to provide confidence in the identity of the entities connected.
Selective-Field Confidentiality - answer Confidentiality of selected fields within the user data on a connection or in a single data block. Traffic-Flow Confidentiality - answer Confidentiality of selected fields within the user data on a connection or in a single data block. Data Integrity - answer The assurance that data received are exactly as sent by an authorized entity (i.e., contain no modification, insertion, deletion, or replay). 5 categories of Data Integrity - answer 1. Connection Integrity with Recovery
- Connection Integrity without Recovery
- Selective-Field Connection Integrity
- Connectionless Integrity
- Selective-Field Connectionless Integrity Connection Integrity with Recovery - answer Provides for the integrity of all user data on a connection and detects any modification, insertion, deletion, or replay of any data within an entire data sequence, with recovery attempted. Connection Integrity without Recovery - answer As above but provides only detection without recovery.
Selective-Field Connection Integrity - answer Provides for the integrity of selected fields within the user data of a data block transferred over a connection and takes the form of determination of whether the selected fields have been modified, inserted, deleted, or replayed. Connectionless Integrity - answer Provides for the integrity of a single connectionless data block and may take the form of detection of data modification. Additionally, a limited form of replay detection may be provided Selective-Field Connectionless Integrity - answer Provides for the integrity of selected fields within a single connectionless data block; takes the form of determination of whether the selected fields have been modified. Nonrepudiation - answer Provides protection against denial by one of the entities involved in a communication of having participated in all or part of the communication. 2 categories of Nonrepudiation - answer 1. Nonrepudiation, Origin
- Nonrepudiation, Destination
- Authentication Exchange
- Notarization Encipherment - answer The use of mathematical algorithms to transform data into a form that is not readily intelligible. Digital Signature - answer Data appended to, or a cryptographic transformation of, a data unit that allows a recipient of the data unit to prove the source GROUP 1 Cryptography and Network Security and integrity of the data unit and protect against forgery (e.g., by the recipient). Access control - answer Mechanisms that enforce access rights to resources. Data integrity - answer Variety of mechanisms used to assure the integrity of stream of data units. Authentication Exchange - answer Mechanism that ensures the identity of an entity by means of information exchange. Routing Control - answer Selection of particular physically secure routes for certain data and allows routing changes
Notarization - answer The use of third party to assure certain properties of a data exchange. Pervasive Security Mechanisms - answer Mechanisms that are not specific to any OSI security service or protocol layer. 5 categories of Pervasive Security Mechanisms - answer
- Trusted Functionality
- Security Label
- Event Detection
- Security Audit Trails
- Security Recovery Trusted Functionality - answer Process that which is recognized to be correct regarding some criteria such as established by a security policy. Security Label - answer It is an approach of marking of a constrained to a resource (which can be a data unit) that labels or designates the security nature of that resource Event Detection - answer Detection of security-relevant events (forgery, denial of sending or receiving of information, etc.)
Known-Plaintext Analysis (KPA) - answer Attacker uses known plaintext-ciphertext pairs to find the encryption key; it's easier due to available information. Chosen-Plaintext Analysis (CPA) - answer Attacker chooses plaintexts, gets ciphertexts, and attempts to find the key; simple but low success rate. Ciphertext-Only Analysis (COA) - answer The attacker only has ciphertext, making it the hardest attack to implement, but most probable. Chosen Ciphertext Analysis (CCA) - answer A chosen ciphertext attack is an attack where a cryptanalyst chooses a ciphertext and attempts to find a matching plaintext. Adaptive Chosen Plaintext Analysis (ACPA) - answer A cryptanalyst chooses further plaintexts or ciphertexts (adapts the attack) based on prior results. Adaptive Chosen Ciphertext (ACC) - answer Just like in adaptive chosen plaintext, a cryptanalyst chooses further plaintexts or ciphertexts (adapts the attack) based on prior results.
Man-In-The-Middle (MITM) attack - answer Attacker intercepts messages/keys between two parties in a secure channel. Birthday attack - answer Exploits the probability of collisions in a hash function, akin to shared birthdays in a group. Side-channel attack - answer Gathers info from the physical implementation of a cryptographic system, like timing, power, or electromagnetic data. Brute-force attack - answer Tries every possible key until the correct one is found; simple but time-consuming. Differential cryptanalysis - answer Compares plaintext- ciphertext pairs to find encryption algorithm patterns, effective against specific block ciphers. Linear cryptanalysis - answer It is a known plaintext attack that requires access to large amounts of plaintext and ciphertext pairs encrypted with an unknown key. It focuses on statistical analysis against one round of decryption on large amounts of ciphertext. Model of Network Security - answer It is a conceptual framework that describes how to protect a network from
- Private Key Public Key - answer It is shared with others or made available to the public. It is used by anyone who wants to send you an encrypted message. They use your public key to encrypt the message, ensuring that only you can decrypt and read it with your private key. Private Key - answer It is kept secret and known only to you. It is used to decrypt the messages that have been encrypted with your public key. This means that even if someone intercepts the encrypted message, they won't be able to decrypt it without your private key. Enterprise Security - answer Enterprise security involves the various technologies, tactics, and processes used to protect digital assets against unauthorized use, abuse, or infiltration by threat actors. Enterprise security systems also cover the people and policies that organizations use to secure their network infrastructure, including assets such as devices and various endpoints. Core Pillars of Enterprise Security - answer 1. Confidentiality
- Integrity
- Availability
Confidentiality - answer Ensuring that information is only accessible to authorized individuals. Integrity - answer Ensuring that information is accurate and complete. Availability - answer Ensuring that information and systems are available to authorized users when needed. 5 Layers of Enterprise Security - answer 1. Human layer
- Perimeter layer
- Network layer
- Application layer
- Data layer Human layer - answer The most vulnerable to attack. Perimeter layer - answer The boundary between the organization's internal network and the outside world. Network layer - answer The layer that allows devices and systems on the internal network to communicate with each other.
- Compliance and Legal Obligations
- Protection Against Cyber Threats Protection of Sensitive Data - answer Effective security measures safeguard this data from theft, breaches, and unauthorized access, preventing costly data breaches and legal liabilities. Reputation and Trust - answer Maintaining strong security builds trust with customers, partners, and stakeholders, enhancing an organization's credibility. Business Continuity - answer Robust security measures help ensure business continuity by minimizing the impact of security incidents and facilitating rapid recovery. Compliance and Legal Obligations - answer Effective enterprise security helps organizations adhere to these regulations and maintain legal compliance. Protection Against Cyber Threats - answer Enterprise security helps protect against a wide range of threats, including malware, phishing, ransomware, and more, reducing the risk of financial loss and business disruption. Cyber Security - answer It is the practice of protecting systems, networks, and programs from digital attacks.
These cyberattacks are usually aimed at accessing, changing, or destroying sensitive information; extorting money from users via ransomware; or interrupting normal business processes Assets in Cybersecurity - answer • Information
- Data
- Devices
- Networks
- Services Types of Cybersecurity Threats - answer 1. Denial of Service Attack
- Direct Access Attack
- Social engineering
- Ransomware
- Malware
- Phishing Denial of Service Attack - answer It is a cyber-attack meant to shut down a machine or network, making it inaccessible to the end-user. DoS attacks do this by flooding a network with traffic or sending information that results in a machine crashing.
