Problem:

Using the two keys (memory words) cryptographic and network security, encrypt the following message:

"Be at the third pillar from the left outside the lyceum theatre tonight at seven. If you are distrustful bring two friends."

Make reasonable assumptions about how to treat redundant letters and excess letters in the memory words and how to treat spaces and punctuation.

Question-  Indicate what your assumptions are.

Note: The message is from the Sherlock Holmes novel The Sign of Four.

Decrypt the ciphertext.

Please describe the appropriate to use this technique and what its advantages are.