Homework Help is Here – Start Your Trial Now!
Engineering
Computer Engineering
Cipher Block Chaining. Take the following figure below, representing the structure for a block ciphe in Cipher Block Chaining or CBC mode. The below figure is only for a 2-stage CBC structure, with each stage processing 8-bits at a time. It also provides some reference information on how hexadecim digits can be converted to binary and vice versa as well as how the “XOR" operation is performed bit- by-bit.

Cipher Block Chaining. Take the following figure below, representing the structure for a block ciphe in Cipher Block Chaining or CBC mode. The below figure is only for a 2-stage CBC structure, with each stage processing 8-bits at a time. It also provides some reference information on how hexadecim digits can be converted to binary and vice versa as well as how the “XOR" operation is performed bit- by-bit.

Computer Networking: A Top-Down Approach (7th Edition)
Computer Networking: A Top-Down Approach (7th Edition)
7th Edition
ISBN:9780133594140
Author:James Kurose, Keith Ross
Publisher:James Kurose, Keith Ross
Chapter1: Computer Networks And The Internet
Section: Chapter Questions
Problem R1RQ: What is the difference between a host and an end system? List several different types of end...
See similar textbooks
icon
Related questions
Question

I WILL THUMBS DOWN IF YOU COPY AND PASTE AN ANSWER FROM CHEGG

 

7. Cipher Block Chaining. Take the following figure below, representing the structure for a block cipher in Cipher Block Chaining or CBC mode. The below figure is only for a 2-stage CBC structure, with each stage processing 8-bits at a time. It also provides some reference information on how hexadecimal digits can be converted to binary and vice versa as well as how the “XOR" operation is performed bit- by-bit. P: P2 0 = 0000 1= 0001 2 = 0010 ХOR 0 xor 0 = 0 1 = 1 0 xor 0 = 1 IV 3 = 0011 4 = 0100 5 = 0101 1 хor 1 xor 1 = 0 6 = 0110 7 = 0111 8 = 1000 9 = 1001 A = 1010 B = 1011 C = 1100 D= 1101 E = 1110 K K Encrypt Encrypt C; E = 1111 CBC works with ANY encryption algorithm. Suppose that we have a really, really, dumb encryption algorithm which simply performs the following: comp(x), if k = 1 comp(x), if k = 1 E(r, k) = D(r, k) = otherwise otherwise and where, "comp(x)" simply performs the binary "1's complement" of x. For example, the hexadecimal value F2 can be expressed in binary as 11110010 (see the table). The “l’s complement" of this is obtained by simply flipping the bits to give us 00001101, which in hexadecimal is OD. In other words E(F2, 1) = OD. Note the 'key' is simply a single bit that, when it is 1, the complementation is performed, and when it is 0, it is simply left "as is". That is, E(F2,0) = F2 (no change). The circular plus symbol in the above diagram, recall, represents the bitwise XOR operation. For example, the bitwise XOR of two 4-bit values 1010 and 1000 is 0010. CBC shows that for the first stage, we must perform the XOR operation of P1 with an Initial Vector (IV) value prior to encrypting. For this problem, suppose that the plaintext data Pı is the byte 7A (in hexadecimal), and P2 is the byte 2C (in hexadecimal). Use the above diagram, encryption algorithms, with an IV = 55 (in hexadecimal) and a key value of K = 1, to determine the enciphered bytes C1 and C2 (also in НЕХADECIMAL). State your answer as "C1 = ??, C2 = ??". Note for this problem you HAVE to convert form hexadecimal to binary so that everything can be done in binary. Once you get your final answers, reconvert them back to hexadecimal. So, if you compute "11101110" (in binary), then the answer in Hexadecimal is "EE".
Transcribed Image Text:7. Cipher Block Chaining. Take the following figure below, representing the structure for a block cipher in Cipher Block Chaining or CBC mode. The below figure is only for a 2-stage CBC structure, with each stage processing 8-bits at a time. It also provides some reference information on how hexadecimal digits can be converted to binary and vice versa as well as how the “XOR" operation is performed bit- by-bit. P: P2 0 = 0000 1= 0001 2 = 0010 ХOR 0 xor 0 = 0 1 = 1 0 xor 0 = 1 IV 3 = 0011 4 = 0100 5 = 0101 1 хor 1 xor 1 = 0 6 = 0110 7 = 0111 8 = 1000 9 = 1001 A = 1010 B = 1011 C = 1100 D= 1101 E = 1110 K K Encrypt Encrypt C; E = 1111 CBC works with ANY encryption algorithm. Suppose that we have a really, really, dumb encryption algorithm which simply performs the following: comp(x), if k = 1 comp(x), if k = 1 E(r, k) = D(r, k) = otherwise otherwise and where, "comp(x)" simply performs the binary "1's complement" of x. For example, the hexadecimal value F2 can be expressed in binary as 11110010 (see the table). The “l’s complement" of this is obtained by simply flipping the bits to give us 00001101, which in hexadecimal is OD. In other words E(F2, 1) = OD. Note the 'key' is simply a single bit that, when it is 1, the complementation is performed, and when it is 0, it is simply left "as is". That is, E(F2,0) = F2 (no change). The circular plus symbol in the above diagram, recall, represents the bitwise XOR operation. For example, the bitwise XOR of two 4-bit values 1010 and 1000 is 0010. CBC shows that for the first stage, we must perform the XOR operation of P1 with an Initial Vector (IV) value prior to encrypting. For this problem, suppose that the plaintext data Pı is the byte 7A (in hexadecimal), and P2 is the byte 2C (in hexadecimal). Use the above diagram, encryption algorithms, with an IV = 55 (in hexadecimal) and a key value of K = 1, to determine the enciphered bytes C1 and C2 (also in НЕХADECIMAL). State your answer as "C1 = ??, C2 = ??". Note for this problem you HAVE to convert form hexadecimal to binary so that everything can be done in binary. Once you get your final answers, reconvert them back to hexadecimal. So, if you compute "11101110" (in binary), then the answer in Hexadecimal is "EE".
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 4 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Recommended textbooks for you
Computer Networking: A Top-Down Approach (7th Edi…
Computer Networking: A Top-Down Approach (7th Edi…
Computer Engineering
ISBN:
9780133594140
Author:
James Kurose, Keith Ross
Publisher:
PEARSON
Computer Organization and Design MIPS Edition, Fi…
Computer Organization and Design MIPS Edition, Fi…
Computer Engineering
ISBN:
9780124077263
Author:
David A. Patterson, John L. Hennessy
Publisher:
Elsevier Science
Network+ Guide to Networks (MindTap Course List)
Network+ Guide to Networks (MindTap Course List)
Computer Engineering
ISBN:
9781337569330
Author:
Jill West, Tamara Dean, Jean Andrews
Publisher:
Cengage Learning
Concepts of Database Management
Concepts of Database Management
Computer Engineering
ISBN:
9781337093422
Author:
Joy L. Starks, Philip J. Pratt, Mary Z. Last
Publisher:
Cengage Learning
Prelude to Programming
Prelude to Programming
Computer Engineering
ISBN:
9780133750423
Author:
VENIT, Stewart
Publisher:
Pearson Education
Sc Business Data Communications and Networking, T…
Sc Business Data Communications and Networking, T…
Computer Engineering
ISBN:
9781119368830
Author:
FITZGERALD
Publisher:
WILEY
SEE MORE TEXTBOOKS