Informational Security Assignment | Homework For You
Question 1:
Information security is used to describe the tasks of protecting information in a digital form. To better understand the concepts of information security, you should be familiar with the key characteristics of information, which are expressed in the C.I.A triad characteristics, as shown in the follow figure:
(1) Explain these three key objectives of information security.
(2) Give examples of confidentiality, integrity and availability requirements associated with the ATM system in which users provide a bank card for account access and a personal identification number. 
Question 2
Security experts have discovered that many Internet of Things (IoT) devices including routers, DVRs and cameras could be potentially recruited into botnet because of a malicious software program Mirai, which emerged in 2016 and possibly becomes one of the biggest IoT-based malware threats. Hackers could use such malware to scan insecure Linux-based connected devices, enslave them into a botnet network, and used that to launch massive DDoS attacks to make internet outage, such as an attack on 20 September 2016 on computer security journalist Brian Krebs’s website, an attack on French web host OVH and the October 2016 Dyn cyberattack.
(1) Research the Mirai malware to indicate possible issues of vulnerable devices and provide at least two strategies to prevent such botnet from spreading;
(2) Discuss types of hackers/attackers playing different roles in this case;
(3) Explain what a DDoS attack is and give basic steps to launch such a DDoS attack in this case study.
Question 3
Integrity protection is used to guard against improper information modification or destruction, including ensuring information nonrepudiation and authenticity.
(1) Calculate message-digest fingerprints (checksum) for the provided files shattered-1&2.pdf:
(2) Explain why the Hash algorithm SHA256 is more secure than MD5 and SHA1;
(3) Based on the derived results in (1), explain why the Google Company announced that they achieved successful SHA-1 collision attack in the early of this year (2017).
Question 4
The earliest and the simplest use of a substitution cipher was by Julius Caesar.
Assume that Alice received the following message “skkz sk glzkx znk zumg vgxze” from Bob, who used Caesar Cipher to let Alice know “meet me after the toga party”. The Vigenère cipher is a method of encrypting alphabetic text by using a series of interwoven Caesar ciphers based on the letters of a keyword. It is a form of polyalphabetic substitution.
Please complete the following tasks:
(1) Research Vigenère cipher and indicate the differences between Caesar and Vigenère ciphers;
(2) By using Vigenère cipher, choose a key to encrypt the plaintext “meet me after the toga party”;
Plaintext meet me after the toga party
Key
ciphertext
(3) Explain an approach that can be used to attack Vigenère cipher. Is it possible to improve the cryptographic algorithm?
Question 5:
RSA is an algorithm to encrypt and decrypt messages. RSA stands for Ron Rivest, Adi Shamir and Leonard Adleman, who first publicly described RSA in 1978. A user of RSA creates and then publishes the product of two large prime numbers along with an auxiliary value as their public key. The prime factors must be kept secret. Anyone can use the public key to encrypt a message. However, with currently published methods, if the public key is large enough, only someone with knowledge of the prime factors can feasibly decode the message.
Answer the following questions:
(1) Explain what category of cryptographic algorithms RSA belongs to.
(2) Explain how RSA is used to achieve the cryptography (encryption and decryption) and digital signatures.
(3) Explain the main weakness of digital signatures and how this weakness can be compensated for. Get Networking homework help for you today
