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
Bit in key
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:
Cypher text result
The encrypted bits are the cypher text, or 0100 1011 as shown. These (encrypted) bits are what the software would transmit to the recipient.
1. Decrypting the cipher text created by an XOR operation is easyjust use the same XOR operation on the encrypted bits! Demonstrate this for the example above.
2. Suppose the secret key were longerthe 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.)