Expanding randomness. Alice wants to implement AES in CTR mode on a small IoT device that doesn’t have a good source of randomness. She has observed that, in practice, she can obtain four random bits for each encryption. To produce the 64 bits of nonce needed for each encryption, she proceeds as follows. She takes the SHA256 of the four random bits. Then she uses the first 64 bits of the SHA256 output as the nonce. Is this method secure? Explain your reasoning. (Hint: consider what happens if the adversary tries to guess the nonce. How many possibilities are there? Would guessing the nonce help them decrypt the message?)

Q: Problem 3. You are stuck in some city s in a far far away land and you know that your only way out…

A: This is a simple variation of the standard Breadth Search Problem(BFS) . The only difference in this…

Q: not a quiz or test but homework

A: Step 1: Step 2:section .textglobal ValidatePIN; Input: ESI = pointer to PIN (array of 5 bytes);…

Q: make a code  used mathlab if possible  please dont uses if or return keep it basic

A: Coded using matlab.

Q: 1. Alice decides to use the RSA cryptosystem to enable individuals to communicate secret in-…

A: Part (a) - Finding Decryption Exponent (d):Input the RSA public key parameters: N and e.Calculate…

Q: Consider you are standing at a street corner, in a city where the streets are laid out in a very…

A: Code: This programe helps to estimate the expected distance a man would move from astarting point…

Q: This is a substitution cypher Each letter is replaced by another letter with no repetition Ignore…

A: import string alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" key = "XPMGTDHLYONZBWEARKJUFSCIQV" def…

Q: Reimplement the digital clock from the preceding exercise, representing the time as the minutes from…

A: Actually, program is an executable software that runs on a computer.

Q: Consider the following generalised NFA M₂: Start- 90 01 0 q2 101 11 10 93 q1 00 Convert M3 to a…

A: Convert the NFA to an equivalent Generalized NFA (GNFA): A GNFA is an NFA where each transition has…

Hash Table

A hash table also called a hash map, is a data structure that maps key-value pairs. The hash table can be used in complex systems to provide fast access and compact storage. A hash table is a structure that stores data in an abstract data type kind of associative array. It keeps data in an array format, with a distinct index value for every data value. If the index of the required data is known, then the data can be accessed very easily.