1. The following ciphertext was encrypted using a 3 x 3 Hill cipher: JMUP ZMLZ. YAK. JN.SRXEW The encryption key was: [21 16 21] K = 19 20 20. | 23 5 8 Decrypt the plaintext. To help, here is a fact that you may use: [15 16 4] [21 16 21] [15 0 0 1 19 2 : 19 20 201%29 = 0 15 0 13 15 o] [235 8] lo 015] If you use this fact, clearly explain how you use it. In any case, include enough details to convince David that you understand how to use the Hill cipher, and especially that you understand how inverse matrices are involved. 1. The following ciphertext was encrypted using a 3 x 3 Hill cipher: JMUP ZMLZ. YAK. JN.SRXEW The encryption key was: [21 16 21] K = 19 20 20. | 23 5 8 Decrypt the plaintext. To help, here is a fact that you may use: [15 16 4] [21 16 21] [15 0 0 1 19 2 : 19 20 201%29 = 0 15 0 13 15 o] [235 8] lo 015] If you use this fact, clearly explain how you use it. In any case, include enough details to convince David that you understand how to use the Hill cipher, and especially that you understand how inverse matrices are involved