Cipher Encryption

Julius Caesar used a extremely simple substitution cipher to send messages to his troops. He substituted each letter by the letter that was 3 places further along in the alphabet, so that “a” was replaced with “D”, “b” with “E” and so on. This is a substitution cipher with a key of 3.

Using a key of 5, encrypt the word miami

Julius Caesar used a extremely simple substitution cipher to send messages to his troops. He substituted each letter by the letter that was 3 places further along in the alphabet, so that “a” was replaced with “D”, “b” with “E” and so on. This is a substitution cipher with a key of 3.

Using a key of 7, encrypt the word cheeseburger

Decryption is the technique of reversing an encrypted message into plaintext. If we know the key used to encrypt, we can easily subtract the key value to find the plaintext.

If a key of 9 was used to perform the encryption, decrypt the following word: yriij

Decryption is the technique of reversing an encrypted message into plaintext. If we know the key used to encrypt, we can easily subtract the key value to find the plaintext.

If a key of 4 was used to perform the encryption, decrypt the following word: LETTC JVMHEC

Convert "GJGB" cipher-text back into plain text using the key: 1

• FIFA

• HOME

• COCO

• YEAR

CHICKEN WINGS is plain text and the cipher text is: MRSMUOX GSXQC - What would the encryption key be?

• 10

• 7

• 6

• 11

SUBWAY is plain text and the cipher text is: WYFQAEC - What would the encryption key be?

• 10

• 4

• 6

• 3