For affine cipher, the key is a pair (a,b) for a,b<26. The encryption algorithm is E(x)=(ax+b) mod 26. And the decryption algorithm is D(y)=a¹(y-b) mod 26. Note that we map A, B, C, D, ... to numbers 0, 1, 2, 3, ... respectively. Assume that K=(7,3), then E(x)=(7x+3) mod 26, and 7-1-15. Thus D(y)=15(y-3) mod 26. 1. For the key K=(7,3), computer the cipher text for "GOLUNCH" is (please use all capital letters) 2. For the key K=(7,3), try to decrypt the cipher text "YHQQFPGHJF" is (please use all capital letters)

For affine cipher, the key is a pair (a,b) for a,b<26. The encryption algorithm is E(x)=(ax+b) mod 26. And the decryption algorithm is D(y)=a¹(y-b) mod 26. Note that we map A, B, C, D, ... to numbers 0, 1, 2, 3, ... respectively. Assume that K=(7,3), then E(x)=(7x+3) mod 26, and 7-1-15. Thus D(y)=15(y-3) mod 26. 1. For the key K=(7,3), computer the cipher text for "GOLUNCH" is (please use all capital letters) 2. For the key K=(7,3), try to decrypt the cipher text "YHQQFPGHJF" is (please use all capital letters)

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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Question

For affine cipher, the key is a pair (a,b) for a,b<26. The
encryption algorithm is E(x)=(ax+b) mod 26. And the
decryption algorithm is D(y)=a¹(y-b) mod 26. Note that we
map A, B, C, D, ... to numbers 0, 1, 2, 3, ... respectively.
Assume that K=(7,3), then E(x)=(7x+3) mod 26, and 7-1-15.
Thus D(y)=15(y-3) mod 26.
1. For the key K=(7,3), computer the cipher text for
"GOLUNCH" is
(please use all capital
letters)
2. For the key K=(7,3), try to decrypt the cipher text
"YHQQFPGHJF" is
(please use all
capital letters)

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