Cryptography Key Generation Process

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Questions and Answers

What is the output of the left shift operation on the first part after applying P10?

10101 (correct)

10110

11010

01100

Which compression P-box mapping is used when generating K1?

(8,7,6,5,4,3,2,1)

(1,2,3,4,5,6,7,8)

(7,6,4,5,3,2,10,9)

(6,3,7,4,8,5,10,9) (correct)

After the final output for K2 is generated, what is the output sequence?

1010 1010

0001 1110

1110 0100

0101 0011 (correct)

What is the input sequence applied before the compression step to generate K1?

1010101010 Signup and view all the answers

What is the output of the second compression P-box operation used for generating K2?

0101 0011 Signup and view all the answers

What is the output after the Initial Permutation (IP) for the input 10101010?

00110011 Signup and view all the answers

How is the 4-bit Right Part expanded in Step 2 of the encryption process?

Using the Expansion Permutation (Ep) Signup and view all the answers

What is the result after performing the XOR operation with the key in Step 3?

01110010 Signup and view all the answers

Which part of the XOR result is used for the Substitution Box process?

The Right Part of the XOR Result Signup and view all the answers

What does the Substitution Box (S-Box) output after processing the specified input values?

0000 Signup and view all the answers

Which permutation is applied after obtaining the S-Box result?

P4 Signup and view all the answers

What is the final output after XORing the S-Box output with the Left Part of the IP Result?

0111 Signup and view all the answers

In the context of this encryption process, what is the purpose of the XOR operation?

To combine the data with the encryption key Signup and view all the answers

What is the output of ROUND 1 after the SWAP operation?

00110111 Signup and view all the answers

What is the result of the Expansion Permutation (Ep) operation on the 4-bit Right Part?

10111110 Signup and view all the answers

After XORing the 4-bit Left Part and XOR Result, what is the combined output?

10100111 Signup and view all the answers

What would be the output after applying the IP Inverse to the input 10100111?

01101011 Signup and view all the answers

What is the final output of the entire process represented in hexadecimal format?

6B Signup and view all the answers

Study Notes

Key Generation Process

P Box (P10): The first permutation that takes a 10-bit input and reorders it to output a sequence based on positions (3, 5, 2, 7, 4, 10, 1, 9, 8, 6).
Input Sequence (I/P): Example input 1010101010 translates through P10 to output 1101001100.
Left Shifts: The input is divided into two 5-bit segments, shifting left by 1 bit for each segment.
Compression P-Box: Function compresses 10 bits to 8 bits, with the pattern defined by (6, 3, 7, 4, 8, 5, 10, 9).
Keys Generated: Two key outputs, K1 (11100100) and K2 (01010011), are derived for encryption rounds.

Encryption Process

Step 1 - Initial Permutation (IP): Reorders 8-bit plaintext input (10101010) to 00110011 based on positions (2, 6, 3, 1, 4, 8, 5, 7).
Step 2: Split the permuted output into left (00) and right (11) parts.
Step 3 - Expansion Permutation (EP): Expands the right part from 4 bits to 8 bits following the order (4, 1, 2, 3, 2, 3, 4, 1), resulting in 10010110.

XOR Operation and Substitution

XOR with K1: The expanded output (10010110) is XORed with K1 (11100100) yielding 01110010.
Split for S-Box Input: Divided into left (0111) and right (0010) segments.
S-Box Lookup: Utilizes S-Boxes (S0 and S1) to get new values, resulting in 0001 in the S-Box process.
P4 Shuffle: The S-Box output is permuted using P4 resulting in 0100.

Final Operations

XOR with Left Part: The P4 output (0100) is XORed with the left part of the previous result leading to 0111.
Combine: Left (0111) and right (0011) parts are combined to form the new swapped segment (00110111).
Round 2: Similar steps are performed; the left and right parts are expanded and XORed with K2.

Final Permutation and Result

Final Output Post-Round 2: The result is processed through IP Inverse (4, 1, 3, 5, 7, 2, 8, 6), resulting in the final encrypted output (01101011).
Final Answer: The last output translates to 6B in hexadecimal.

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Description

This quiz covers the key generation process in cryptography, focusing on the P Box (P10), input sequences, left shifts, and the compression P-Box. Learn how these components work together to produce keys for encryption. Additionally, it delves into the initial permutation and encryption steps involved in the process.