1 / 3 Security in Computing and IT (CPT251) Assignment 2, OUA SP2, 2016 Aims • To get some hands-on experience with encryption Method This assignment will be attempted by students individually. Time frame Time allocated for this assignment: 4 weeks Due date: End of Week 11 (Sunday, 14 August, 2016, 11:59pm) Special Consideration With the exception of dire circumstances, no extension requests will be considered within 5 working days of the submission date. ("Dire Circumstances" means things like hospitalisation of you or a close relative, etc.) Persons requesting a late extension may be required to prove that a significant body of the work has already been completed. Submission What to submit A zip file named s< Your Student Number >.zip. (Replace with your own student number). The zip file should contain all your answer files. Each answer file must be named exactly as described in the specification below. As the files will automatically be distributed to markers by a script, wrongly named files may not be assigned to any marker (i.e. will not be marked). Submission method Submission is via the Blackboard facility. Marking This assignment contributes 15% towards your final mark in the course, and will be marked out of 75. Students are reminded that cheating, whether by fabrication, falsification of data, or plagiarism, is an offence subject to University disciplinary procedures. In particular, students should acknowledge any material that is not their own work and is submitted as part of an assignment. Students should be aware of their rights and responsibilities regarding the use of copyright material. If you need help referencing, have a look at RMIT's Referencing Guide.2 / 3 Tasks In this part you will practice encrypting and digital signature. Task 1.1 You are to encrypt your last name using a Caesar cipher, the key for the cipher will be the sum of all the digits of your student number modulo 10. (Modulo 10 means dividing the sum by 10 and taking the remainder as the result.) NOTE: If your name is hyphenated, just leave out the hyphen. Example: If my student number is s3333371, I would do (3+3+3+3+3+7+1) % 10 which equals 3 (this is the key I will use for the shift). If mod result is 0 then use 10. You must save the resulting ciphertext in a file called XXXXXXX_task_11.txt (where XXXXXXX is your student number without the "s" or any alphabet at the end) and include it in your submission. No additional text must be included in the file and the cipher should be written in lowercase. There is no need to include the key, since it is derived from the student number we will compute it automatically when marking. [10 marks] Task 1.2 You are to take a SHA256 hash of your student number (without the "s" and excluding all newline/end of line character). Example: If my student number is s3333371, the hash is 0d6fdabc5c61b408dcb01bb79a15a19311ac21a3c78285b9e5a807d10b0a3007 NOTE: For this task, make sure you include only the student number and nothing else in the hash calculations (e.g. exclude all newline/end of line character). You must save the resulting hash in a file called XXXXXXX_task_12.txt (where XXXXXXX is your student number without the "s" or any alphabet at the end) and include it in your submission. No additional text must be included in the file except the hash. [20 marks]3 / 3 Task 1.3 You must generate an RSA public/private keypair. You must then take the same SHA256 hash from task 1.2 and create a digital signature by encrypting the same hash with your RSA private key. Hint: We recommend looking at openssl tool. Alternatively, you can search for some online tools, and use those. You must save the resulting ciphertext in a file called XXXXXXX_task_13.txt (where XXXXXXX is your student number without the "s" or any alphabet at the end). No additional text must be included in the files. You must also submit your user generated public and private key files; name them XXXXXXXpub.key and XXXXXXXpri.key respectively (where XXXXXXX is your student number without the "s" or any alphabet at the end). [45 marks] The End