to provide a simple and effective method for encoding and decoding messages.
The numbers 1 – 26 have been assigned to letters of the alphabet as shown below. Additionally, the number 0 has been assigned to a blank to provide space between words.
| Blank | A | B | C | D | E | F | G | H | I | J | K | L | M |
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |
You have chosen to use the following (3 x 3) encoding matrix to encode messages:
A counterpart in Berlin has recently sent you the following confidential message. Let B represent a (3 x 14) matrix containing this original message. The coded message is therefore derived by multiplying A and B, i.e. coded message = AB. The coded message is as follows:
- Find the inverse of the encoding matrix [Use Gauss Jordan and show full working out].
- What is the original (decoded) message?
- Encode an appropriate response to this nationally sensitive message. The message must be between 21 and 42 characters (i.e. your matrix cannot be more than 14 columns) and be encoded by the same matrix. In your answer please include:
- Your secret message presented as full sentence and without
- Your encoded message with encoding (that is after multiplying by ). This should be performed using the same methodology as matrix and be presented in 3 rows by
- Briefly describe three industries in which cryptography still play an important role today.
