Barra Concrete (XOR Encryption) Barra Concrete specializes in creating driveways and curbs for the…

Need your ASSIGNMENT done? Use our paper writing service to score better and meet your deadline.


Order a Similar Paper HERE Order a Different Paper HERE

Barra Concrete (XOR Encryption) Barra Concrete specializes in creating driveways and curbs for the residential market. Its accounting software uses exclusive OR (XOR) operations to convert the individual bits of a plaintext message into cyphertext. The rules are as follows:

Exclusive OR rules

Rule 1

Rule 2

Rule 3

Rule 4

Plaintext bit

$0

0

$1

1

Bit in key

0

1

0

1

Cypertext result

0

1

1

0

In other words, exactly one of the bits must be a ‘‘1’’ and the other a ‘‘0’’ for the result of an exclusive OR operation to be a ‘‘1.’’ To illustrate, suppose that the bits representing a single plaintext character were 1010 0101 and the secret key used just the four bits 1110.

Here are the results of the XOR operation, using this key:

Plaintext bits

1010

101

Key (repeated)

1110

1110

Cypher text result

100

1011

The encrypted bits are the cypher text, or 0100 1011 as shown. These (encrypted) bits are what the software would transmit to the recipient.

Requirements:

1. Decrypting the cipher text created by an XOR operation is easy—just use the same XOR operation on the encrypted bits! Demonstrate this for the example above.

2. Suppose the secret key were longer—the eight bits 1100 0011. Using this key and an exclusive OR, what is the cipher text for the plaintext message ‘‘Go, team’’ if the bit configuration for these letters is as shown below. (Hint: the final answer consists of seven sets of data, each containing eight bits.)

Message

G

O

,

T

E

A

M

Binary

0100 0111

0100 1111

0010 1100

0101 0100

0100 0101

0100 0001

0100 1101