1. We discussed how use a meet in the middle attack to break 2DES using a known-plaintext attack. Now we want to adapt it to break 3DES. We use the following diagram. Here, we are attempting to break DESKI (DESKI (DESki (m))) by attempting to find K1, K2. Show that you can find K1, K2 with a chosen plaintext using attack 20 chosen plaintexts and two tables of 290 entries of DES inverse operations. (Hint: start by constructing a table with 2 entries of all possible Kl and corresponding DES (0) (that is, assume A = 0.) Using A = 0, meet in the middle.) K1 K2 K1 Plaintext m Ciphertext 1. We discussed how use a meet in the middle attack to break 2DES using a known-plaintext attack. Now we want to adapt it to break 3DES. We use the following diagram. Here, we are attempting to break DESKI (DESKI (DESki (m))) by attempting to find K1, K2. Show that you can find K1, K2 with a chosen plaintext using attack 20 chosen plaintexts and two tables of 290 entries of DES inverse operations. (Hint: start by constructing a table with 2 entries of all possible Kl and corresponding DES (0) (that is, assume A = 0.) Using A = 0, meet in the middle.) K1 K2 K1 Plaintext m Ciphertext