**AES Decryption Process: Inverse Shift Rows Transformation**In the context of the AES (Advanced Encryption Standard) decryption process, one of the crucial steps involved is the Inverse Shift Rows transformation. This step is essential for reverting the transformation applied during encryption and contributes to the overall security of the cipher.**Problem Statement:**During the AES decryption operation, the State array from the previous round contains the following 128 bits: `32 83 E2 3F BA 36 81 DC F2 67 43 4D 6D 24 1A F8 D9`The task is to determine the content of the State array following the Inverse Shift Rows transformation.**Understanding Inverse Shift Rows:**- **Inverse Shift Rows** is applied to the State array during AES decryption. The rows of the array are shifted to the right. Specifically: - The first row remains unchanged. - The second row is shifted one position to the right. - The third row is shifted two positions to the right. - The fourth row is shifted three positions to the right.By reversing the row shifts applied during the encryption, the Inverse Shift Rows operation restores the original order, helping revert the data to its initial form.This transformation is illustrated by reorganizing the bytes in each row according to the specified shifts. After performing this transformation, the new configuration of the State array is critical for the next steps in the decryption process, which ultimately lead to the retrieval of the original plaintext.

Answered: If the State array contains the…

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

See similar textbooks

Related questions

Concept explainers

Question

**AES Decryption Process: Inverse Shift Rows Transformation**

In the context of the AES (Advanced Encryption Standard) decryption process, one of the crucial steps involved is the Inverse Shift Rows transformation. This step is essential for reverting the transformation applied during encryption and contributes to the overall security of the cipher.

**Problem Statement:**

During the AES decryption operation, the State array from the previous round contains the following 128 bits:

`32 83 E2 3F BA 36 81 DC F2 67 43 4D 6D 24 1A F8 D9`

The task is to determine the content of the State array following the Inverse Shift Rows transformation.

**Understanding Inverse Shift Rows:**

- **Inverse Shift Rows** is applied to the State array during AES decryption. The rows of the array are shifted to the right. Specifically:
- The first row remains unchanged.
- The second row is shifted one position to the right.
- The third row is shifted two positions to the right.
- The fourth row is shifted three positions to the right.

By reversing the row shifts applied during the encryption, the Inverse Shift Rows operation restores the original order, helping revert the data to its initial form.

This transformation is illustrated by reorganizing the bytes in each row according to the specified shifts. After performing this transformation, the new configuration of the State array is critical for the next steps in the decryption process, which ultimately lead to the retrieval of the original plaintext.

Expert Solution

Step 1

In Inverse Shift Row operation, on each row of bytes, a cyclic right shift operation is performed and the result is stored back to the state.

Input State Array:

_S0,0	_S0,1	_S0,2	_S0,3
_S1,0	_S1,1	_S1,2	_S1,3
_S2,0	S_2,1	S_2,2	S_2,3
S_3,0	S_3,1	_S3,2	S_3,3

The first row in the input state array remains the same.
The second row in the input state array is shifted 1 byte to the right in a circular manner.
The second row in the input state array is shifted 2 bytes to the right in a circular manner.
The second row in the input state array is shifted 3 bytes to the right in a circular manner.

The Outcome of state array after Inverse Shift Row:

_S0,0	_S0,1	_S0,2	_S0,3
_S1,3	_S1,0	_S1,1	_S1,2
S_2,2	S_2,3	_S2,0	S_2,1
S_3,1	_S3,2	S_3,3	S_3,0

Step by step

Solved in 2 steps

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.

Similar questions