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Contains questions related to cyber security, information governance, cyber ethics, cryptography related numerical...etc
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MURALI RAVI NARAYAN DATE: 17/11/ 500090374 R MTECH CSE (1ST^ YEAR) MM: 20
1. What are the 5 steps of the Information Security Program Lifecycle? Discuss the role of Life cycle management in maintaining strong cyber security. Ans. The steps in information security lifecycle are: Identify the assets Assess and review the security issues Design solutions and countermeasures based on the assessment Implement the solutions and countermeasures Protect the systems from the changes made Monitor and verify the enhanced security and identify any new vulnerabilities when they emerge For enforcing the lifecycle process in an organization, it should have a strong foundation of policies and procedures in place, which the lifecycle process depends on. Since the threats are also evolving, your organization’s security should also evolve and change shape in the same way. That’s why responsible manufacturers release bug fixes and patches regularly to address vulnerabilities of all levels and resolve other issues that may hamper performance over time. 2. What is Information System and types of information system? Ans. Information system is a combination of people, processes, networks and data. It is an interrelated system used for collecting, storing, distributing and processing data and information. Types of information systems: Operating systems Transaction processing systems Management information systems Decision support systems Expert systems 3. What is Information Security explain the need of information security? Ans. Information security is the protection and prevention of unauthorized access, use, distribution, disclosure, modification and inspection of information. It is a crucial part of cyber security. Confidentiality, Integrity and Availability – the CIA triad – are the core concepts or pillars of information security. Information security is basically needed to allow only the authorized personnel to access the data while keeping the unauthorized person out. Since information is the most crucial and important component of any organization – be it employee data, projects details, transaction information, banking details…etc – it is very important that information be protected at all costs so that hacker groups and criminal organization can’t damage the reputation of the organization and misuse customers’ information. 4. What are the 3 principles of information security? How can we protect information security?
Ans. The three principles of information security are: Confidentiality (only authorized personnel are allowed to access data) Integrity (information should be consistent, correct and trustworthy) Availability (information should be readily available through proper authorization even in case of technical failures) These three pillars of information security do not work separately, but work in tandem to achieve information security. These competing factors work together and affect one another. Information security does not just include computer systems and digital data, but also physical information like printed data, memory devices, networking devices…etc. So protecting every aspect of information be it digital or physical, and enforcing the three pillars of information security is how we achieve and maintain information security.
5. What are the types of threats to security of information systems? Ans. Types of threats to information systems are: Man-made threats: theft, electrical failures, fires, outdated softwares…etc Natural threats: earthquakes, floods, natural disasters…etc Political threats: riots, strikes…etc Insider threats: espionage, fraud, sabotage…etc Software attacks: Malware, virus, worm, trojan horse, spyware, adware, logic bomb, denial of service, distributed denial of service…etc 6. What are the 5 areas of information assurance? Ans. Areas of information assurance are: Confidentiality: preventing private information from disclosure and unauthorized access Integrity: data should be accurate, consistent and trustworthy Availability: data should be easily available only to authorized personnel in case of technical failures Authentication: verifying your identity, who you are Non-repudiation: information needed to confirm the activity of an individual like logs and digital signatures 7. What is the CIA triad and why is it important for cybersecurity? Ans. CIA triad – Confidentiality, Integrity and Availability are the fundamental pillars of information security. These three pillars of information security do not work separately, but work in tandem to achieve information security. These competing factors work together and affect one another. The CIA triad provides a simple yet comprehensive high-level checklist for the evaluation of your security procedures and tools. Ideally, when all three standards have been met, the security profile of the organization is stronger and better equipped to handle threat incidents. 8. How CIA play an important role in an organizations overall security? Ans. The CIA triad provides a simple yet comprehensive high-level checklist for the evaluation of your security procedures and tools. Ideally, when all three standards have been met, the security profile of the organization is stronger and better equipped to handle threat incidents.
Threat is the potential cause of an attack when a vulnerability is exploited, which causes harm to an organization. Vulnerability means a loophole in the security system which can be exploited. Attack is an event for accomplishing a task like gaining access to a system or getting information by exploiting the vulnerability of that organization.
13. What are Virus and Worms? Ans. Virus (Vital Information Resource under Siege) is a malware that attaches itself to a program, which when opened changes the operations of a system without the user’s knowledge and causes harm. It cannot replicate itself like a worm, and can only be spread when the infected host file is transferred from one system to another. Their damage can range from mildly annoying effects to causing denial of service conditions. Worm is a malware that is similar to viruses, but unlike viruses, they can replicate themselves and do not need human intervention or a host file to spread from one system to another. They enter the system through file or information transport systems and then spread from one system to another. 14. Differentiate between symmetric and asymmetric cipher. Encrypt the plaintext using this Play fair cipher having key “Sunil” and message is: “cryptography is a secret writing”. Ans. Symmetric ciphers are those ciphers that use the same key for encryption and decryption. Asymmetric ciphers are those ciphers that use one key for encryption and another key for decryption, ex: private key and public key. S U N I L A B C D E F G H J/K M O P Q R T V W X Y Z Plaintext -> cr yp to gr ap hy is as ec re tw ri ti ng Ciphertext -> dq wr op jp bo jx lu fa ad td pz yd rl uh 15. Why we use Public key cryptography. Describe the role of RSA algorithm, try to solve the following examples. In RSA, given that p=3, q=11, e=7 and M=6 perform encryption and decryption If n = 35, e = 5 Obtain the value of d. Here n, e, d have usual meanings. Show all the steps of your calculation. Ans. Typically, public key encryption is the cryptography method of choice when there is a multi-user environment and it is necessary to ensure confidentiality through key distribution and digital signatures for verifying user identities. Public key cryptography ensures confidentiality, authenticity and non-repudiation. Public key encryption makes use of keys that are not reversible, hence why it’s also called asymmetric encryption.
RSA algorithm is a strong asymmetric encryption algorithm used for secure data transmission. It makes use of mathematical computations and digital signatures to ensure confidentiality, integrity, authenticity and non- repudiation.
1. p=3, q=11, e=7, M= n = pq = 311 = 33 Q(n) = (p-1)(q-1) = 210 = 20 d = e-1modQ(n) = 7-1mod20 = 3 Encryption: C = Memodn = 6^7 mod33 = 30 Decryption: M = Cdmodn = 30^3 mod33 = 6 So we got the message, M=6 back after decryption. 2. n=35, 3= Since n is a product of prime numbers – p=5, q=7 or p=7, q= Q(n) = (p-1)(q-1) = 46 = 24 d = e-1modQ(n) = 7-1mod24 = (1+k24)/7 = (1+224)/7 = 49/7 = 7 Therefore, d= 16. Describe the Fermat’s and Euler’s Theorem. Describe also its limitations. Find 30^201 mod 11. Ans. Euler’s theorem is a generalized version of Fermat’s theorem, which states that “if x and n are coprime positive integers, then – xf(n)modn = 1modn”. Fermat’s theorem states that “if n is a prime number and x is a positive integer not divisible by n then – xn-1modn = 1modn”. x=30, b=11 (co-primes) f(n) = n-1 = 11-1 = 10 xf(n)modn = 1modn 3010 mod11 = 1mod11 = 1 30201 mod11 = (30^10 )^20 .3mod 30201 mod11 = ((30^10 )^20 mod11)(3mod11) 30201 mod11 = (30^10 )^20 mod11. 30201 mod11 = 1* 30201 mod11 = 3
If it matches, the signature verification is complete.
18. What are typical phases of operation of a virus or worm and how does behavior blocking software work? Ans. Phases of operation of a virus or worm are: Dormant phase Propagation phase Triggering phase Execution phase Behavior-blocking software integrates with the operating system of a host computer and monitors program behavior in real-time for malicious actions. The behavior blocking software then blocks, neither whitelists nor blacklists, potentially malicious actions before they have a chance to affect the system. 19. What is SSL and SET? What is the difference between SSL connection and SSL session? Discuss SSL protocol architecture. How does SET work? Describe dual signature of SET and its purpose. Ans. SSL (Secure Sockets Layer) is a security protocol developed by Netscape designed for securing online transactions. SSL is a protocol for general purpose secure message exchange. SET (Secure Electronic Transaction) is a protocol developed by Visa and MasterCard designed with the goal of securing web browsers for bank transactions. SET is tailored to the credit card payment to the merchant. SSL connection is a transport that provides a type of service, such as peer to peer connections. SSL session has a SSL connection associated with it, like between a client and a server. SSL session is created by handshake protocol and defines a set of cryptographic security parameters to share among multiple connections. SSL architecture: SSL Handshake Protocol | SSL Change Cipher Spec Protocol | SSL Alert Protocol | HTTP SSL Record Protocol TCP (Transport Control Protocol) IP (Internet Protocol) How SET protocol works: Consumer and merchant exchanged certificates to establish transaction Consumer sends purchase request to merchant, sending encrypted credit card information to the merchant’s acquiring bank (which only the acquiring bank can see) to complete purchase Authorization is performed between issuer bank of the consumer and acquiring bank of the merchant, and consumer’s order request is confirmed The consumer then checks on the status information of the purchase Finally, the merchant is allowed to submit authorizations for capture and settlement of the product purchased by consumer. At the time of the delivery of goods or services, merchant will submit a capture request to its own acquiring bank to obtain payment. This request is then forwarded by the acquiring bank over the bankcard network to issuing bank for settlement of payment. The purpose of the dual signature is to link two messages that are intended for two different recipients. In this case, the customer wants to send the order information (OI) to the merchant and the payment
information (PI) to the bank. The merchant does not need to know the customer's credit card number, and the bank does not need to know the details of the customer's order. The cardholder generates a dual signature by passing the order instruction (OI) and payment instruction (PI) through a hash function. The two message digests created (OI message digest and PI message digest) are concatenated. The resulting message is run through a hash function and is encrypted with the cardholder private signature key using RSA signature generation algorithm. This is the dual signature. The dual signature is sent to both the merchant and the bank. When the order and payment instructions are sent by the cardholder, the merchant will be able to read the order instruction, and the banker is able to read only the payment instruction.
20. What is the role of firewall? Describe the function of intruder and malicious software. Ans. Firewalls are used to create a barrier between the internal network and the external environment. Firewalls help in building up trust between the multiple users of a network. A basic standard of security is achieved by allowing only certain traffic to enter the network and deny other traffic which may contain malicious traffic. The Firewall provides an array of features for ensuring the safety of large scale data that the businesses deal with. Firewalls work as the mainline defense mechanisms for the organizations and prevent the dangerous Cyberattacks that may lead to breaching of data. Organizations are thus helped by funneling and authorization of safe incoming and outgoing data. Intruders are used to gain access to a system or increase the range of privileges needed to access the system. They acquire passwords, server information, version information…etc to leverage them to gain access to the system. Intruders are of 3 types: masqueraders, misfeasor and clandestine users. Malicious softwares or malwares are programs that change the operations of a system, overwrite the data of files, spread from one system to another, erases programs and files…etc. They are of two types: ones that are independent of the host file and ones that are dependent on the host file for spreading.