Question 11
Beavers add letters by adding their positions in the alphabet, A=1 through Z=26.
The result is converted back to a letter. For example A+A=B and A+B=C. When the total exceeds 26, counting wraps around from A; for example Z+B=B and Y+C=B. Lenka encrypts a message as follows:
- Choose a random number, called the key.
- Write the message on one line, then write it again on the next line shifted right by the key number of positions.
- Add the letters in each column to obtain the encrypted message; a letter with no partner is unchanged.
For example, TEA with key 1 gives TYFA.
What does COMPUTER give with key 3?
The result is converted back to a letter. For example A+A=B and A+B=C. When the total exceeds 26, counting wraps around from A; for example Z+B=B and Y+C=B. Lenka encrypts a message as follows:
- Choose a random number, called the key.
- Write the message on one line, then write it again on the next line shifted right by the key number of positions.
- Add the letters in each column to obtain the encrypted message; a letter with no partner is unchanged.
For example, TEA with key 1 gives TYFA.
What does COMPUTER give with key 3?