The Feistel cipher is a symmetric block cipher encryption framework which is the basis of many modern day encryption algorithms. In this coursework you will implement a Feistel cipher system as a software implementation in Hack Assembly. In a Feistel cipher the plaintext, P, to be encrypted is split into two equal size parts Lo and Ro such that P = LoRo. A function F is applied to one half of the plaintext, combined with a key, and the result is XOR'd with the other half of the plaintext. Feistel ciphers often employ multiple rounds of this scheme. In general the scheme works as follows, for all i=0,...,N, Li+1 = Ri Ri+1 = L; F(R₁, K₁) To decrypt an encrypted message using this cipher we can apply the same procedure. in reverse. For in,n 1,..., 0, R₁ = Li+1 L₁ = Ri+1 F(Li+1, Ki) For this coursework we are interested in the 16-bit Feistel cipher which uses 4 rounds. The function F(A, B) = A + ¬B. The keys are derived from a single 8-bit key Ko such that, Ko=b7b6b5b4b3b₂b₁bo K1b6b5b4b3b2b1b0b7 K₂ = b5b4b3b2b1bb7b6 K3=b4b3b2b1b0b7b6b5 Write a program (Rotate.asm) in HACK assembly that implements an algorithm to rotate the bits of a 16-bit number left (Least Significant bit (LSb) to Most Significant bit (MSb)). The original number should be stored in RAM[3], the number of times to rotate the bits should be in RAM[4] and the result stored in RAM[5], i.e. 1010111100000000 rotated left 3 times would be 0111100000000101 where the MSb is used to replace the LSb on each rotation.
The Feistel cipher is a symmetric block cipher encryption framework which is the basis of many modern day encryption algorithms. In this coursework you will implement a Feistel cipher system as a software implementation in Hack Assembly. In a Feistel cipher the plaintext, P, to be encrypted is split into two equal size parts Lo and Ro such that P = LoRo. A function F is applied to one half of the plaintext, combined with a key, and the result is XOR'd with the other half of the plaintext. Feistel ciphers often employ multiple rounds of this scheme. In general the scheme works as follows, for all i=0,...,N, Li+1 = Ri Ri+1 = L; F(R₁, K₁) To decrypt an encrypted message using this cipher we can apply the same procedure. in reverse. For in,n 1,..., 0, R₁ = Li+1 L₁ = Ri+1 F(Li+1, Ki) For this coursework we are interested in the 16-bit Feistel cipher which uses 4 rounds. The function F(A, B) = A + ¬B. The keys are derived from a single 8-bit key Ko such that, Ko=b7b6b5b4b3b₂b₁bo K1b6b5b4b3b2b1b0b7 K₂ = b5b4b3b2b1bb7b6 K3=b4b3b2b1b0b7b6b5 Write a program (Rotate.asm) in HACK assembly that implements an algorithm to rotate the bits of a 16-bit number left (Least Significant bit (LSb) to Most Significant bit (MSb)). The original number should be stored in RAM[3], the number of times to rotate the bits should be in RAM[4] and the result stored in RAM[5], i.e. 1010111100000000 rotated left 3 times would be 0111100000000101 where the MSb is used to replace the LSb on each rotation.
Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
Problem 1PE
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please give a step by step implementation of this using only operators in the nand2tetris hack assembly language
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