IERG 4130 – Introduction to Cyber Security (2020 Spring) Assignment 4 Total: 100’ Due Date: May. 28 (Thursday) 11:59 PM Note: Please answer the following questions. Please write down your student id and answers in a single pdf file, then submit to Blackboard. 1. Encrypting email. Send a pretty good privacy (PGP) encrypted email to [email protected] with the subject “Homework for Introduction to Cyber Security”. In the body of the message, please encrypt your name and student ID with the public key provided in the attachment. (40’) Here is a sample email body: —–BEGIN PGP MESSAGE—– hQEMAxb7H85iwvKmAQgAi59D/McVAPw0wbBOKsVkNAc4Ify0A5cFNxMpJwp8W1Le /9/xSMqgeqLstPV+PmMUe7sIbmyaaZznxN/XUi3E+f5hJtSf3n593uTUA5boQof7 JFyCJWADxHimd5Qr69tztmJb+AJTctAsnCfglNUpNSz/1QiIn21i98MH6n3NMUrI YPpccG+5HqaNufJEFFJ6WJW4FHUQHyVJOnYnCLNb3p3TrkePpxbSUIJqxDVETu4M YpeW5RFwOG8Wt5/cf307AW/TesoXlLMwBuifHlKHNOQFVRWlCQnp8cbKgP5b1kNP 5TcOoSqE4s/9lLB8B3w09sPSz7X8rWb+TCsF1cLA59JTAVOWdLxfhKjgAf0fkoHB iQQ0SLAGfTLroMOTKjhVrh8za8hfj9jLPo9L6p/6Yi8xt7+NOIi18xrFg2mHMGCE 5F2vvef34s7R/fPS5uh2xy18Y90= =NCHK —–END PGP MESSAGE—– Hits: There are many tutorials on the internet and you can explore this by yourself. If you have no idea, you can use GNUPG (https://gnupg.org/) Grading: You will get a full mark if we can receive a successfully encrypted email from you (and can decode it). 2. Decrypting message. Alice received the ciphertext “TZJZPQTFPFNINIMMEMOLTGAMPZYMDPZGZADRRAJVPWHTZFOEYHYYPHJMYQMILGZHCS GMLBXIZBXSXDPXPFNCDHZQDHCITBOICBZXLBYATFZPPGNRPHRSCYNXLBYECRNWFQCE DPGYPHJSEVVROKDJTOIHOIZXZHCIRFJAEVJJDAVVERZZTQZWTBXPFRDRRGHECHKLZB ZWESGIGWNMZBNEYROLPJVVTCPWOSQMNSNXSOOGZBNXTHPXPHCITBOICBZXZTOLTBBW ” encrypted by Vigenere Cipher from Bob. But Alice forgot what the key is, only knowing the key length is 4. Can you help Alice to decrypt the message? (60’) Requirements: (1) You can choose the implementation language that you are familiar with, but to facilitate the testing, you should follow the convention that: (a) name executable file: decode ( or decode.py, decode.exe) executable file (b) take one command-line argument as the name of cipher text file (c) print deciphered text to stdout (i.e., the screen) e.g., ./decode cipher.text (2) Submit your source code and a readme file indicating how you solve it. Please be reminded that: DO NOT COPY code from others or the Internet. We will perform code similarity checks, and all plagiarism cases will be given zero marks for and may be reported to the Faculty Discipline Committee for further process. (Hint: Use frequency analysis. You can also refer to the following table for the operation.) + A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A A B C D E F G H I J K L M N O P Q R S T U V W X Y Z B B C D E F G H I J K L M N O P Q R S T U V W X Y Z A C C D E F G H I J K L M N O P Q R S T U V W X Y Z A B D D E F G H I J K L M N O P Q R S T U V W X Y Z A B C E E F G H I J K L M N O P Q R S T U V W X Y Z A B C D F F G H I J K L M N O P Q R S T U V W X Y Z A B C D E G G H I J K L M N O P Q R S T U V W X Y Z A B C D E F H H I J K L M N O P Q R S T U V W X Y Z A B C D E F G I I J K L M N O P Q R S T U V W X Y Z A B C D E F G H J J K L M N O P Q R S T U V W X Y Z A B C D E F G H I K K L M N O P Q R S T U V W X Y Z A B C D E F G H I J L L M N O P Q R S T U V W X Y Z A B C D E F G H I J K M M N O P Q R S T U V W X Y Z A B C D E F G H I J K L N N O P Q R S T U V W X Y Z A B C D E F G H I J K L M O O P Q R S T U V W X Y Z A B C D E F G H I J K L M N P P Q R S T U V W X Y Z A B C D E F G H I J K L M N O Q Q R S T U V W X Y Z A B C D E F G H I J K L M N O P R R S T U V W X Y Z A B C D E F G H I J K L M N O P Q S S T U V W X Y Z A B C D E F G H I J K L M N O P Q R T T U V W X Y Z A B C D E F G H I J K L M N O P Q R S U U V W X Y Z A B C D E F G H I J K L M N O P Q R S T V V W X Y Z A B C D E F G H I J K L M N O P Q R S T U W W X Y Z A B C D E F G H I J K L M N O P Q R S T U V X X Y Z A B C D E F G H I J K L M N O P Q R S T U V W Y Y Z A B C D E F G H I J K L M N O P Q R S T U V W X Z Z A B C D E F G H I J K L M N O P Q R S T U V W X Y
