[SOLVED] Csci262/csci862 system security assignment 1

Part One: Short answer questions:                                                      4 MarksChoose, and place in this order, one lower case letter, following by one upper case letter, followed by two digits, followed by @, followed by two letters, each upper or lower case, and then followed by three symbols drawn from the set {$,9,5,v,w,J}. Finally, apply the hash function Tiger to give an output string in hex which will be used as a password.Assume random choices are made with equal likelihood of each symbol from the space being chosen from. So for a random digit there are 10 possibilities, each chosen with probability 1/10.Alice can climb trees and eat apples.Bob can climb fences, eat apples, and wave flags.Trees can hurt apples.Carol can jump waves and wave flags.Part Two: Implementing a rainbow table                                        6 MarksYou are to write a program, in C/C++ or Java, that compiles on Banshee with an instruction you provide in a file readme.txt. Your program should run on Banshee using the following instruction:$ ./Rainbow Passwords.txtwhere the file Passwords.txt contains a list of possible passwords. The password file contains a password per line, as in /usr/dict/words and consists of strings of printable characters. Any password used must be taken from this file, so the only stored hash information needs to relate to those entries in the file.The program is used to find pre–images for given hash values. Rainbow tables can be used to solve pre–image problems for hash functions. At the simplest level they can simply be a list of hash values and the corresponding pre-images, often from some dictionary. This can be expensive in terms of storage space however, and a more efficient way of identifying pre-images involves the use of the hash function and reduction functions.Your program will do some initial computations to generate the rainbow table. The process is as follows:You are now ready to carry out the second part of the exercise, finding pre–images. Request a hash value from the user. There should be appropriate error checking as to the length of the input string etc. The process of identifying the pre–image for the provided hash value is sketched as follows:A reduction function is designed to take a valid hash value and return a valid password, in this case a valid word from Passwords.txt. The reduction function to be used should be based on the number of words in the Passwords.txt file, and since that isn’t a fixed length file your method needs to be dynamic. You should find a way to convert a hash value to an integer that identifies one of the passwords. You should describe how your reduction function works in readme.txt.You should use MD5 as the hash function. There are implementations of MD5 on Banshee. One is incorrect. Check agianst standards to make sure your hashing is working correctly.