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 theater 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. Indicate what your assumptions are. Decrypt the ciphertext. Show your work.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?

Select the correct answer from each drop-down menu. which types of computer networks are bigger as well as smaller than a man? a man is a network of computers that covers an area bigger than a , but smaller than a .

You draw two cards from a standard deck of 52 cards, but before you draw the second card, you put the first one back and reshuffle the deck. (a) are the outcomes on the two cards independent? why?