2.2 This problem uses a real-world example of a symmetric cipher, from an old U.S. Special Forces manual (public domain). The document, filename Special Forces.pdf, is available at box.com/CompSec3e. 28/ KEY TERMS, REVIEW QUESTIONS, AND PROBLEMS 69 a. Using the two keys (memory words) cryptographic and network security,encrypt the Be at the third pillar from the left outside the lyceum theatre tonight at following message: seven. If you are distrustful bring two friends. Make reasonable assumptions about how to treat redundant letters and excess let- ters in the memory words and how to treat spaces and punctuation. Indicate what your assumptions are. Note: The message is from the Sherlock Holmes novel The Sign of Four. Decrypt the ciphertext. Show your work. b. c. Comment on when t would be appropriate to use this technique and what its advantages are