We consider a banking application, where messages m of the form fromAccount, toAccount, amount are sent within the bank network, with the meaning that amount dollars should be transferred from fromAccount to toAccount. Each message consists of three blocks, with each block holding one of the three parameters. Messages are encrypted using AES in Counter mode, i. e.Kj = E(K, Tj)Cj = Mj ⊕ KjEach of the three parts of a message is sixteen characters, i. e. one block, so messages consist of three blocks. a. The adversary has an account in the bank and can intercept and change messages. Imagine now that he knows the toAccount for a particular message m = C1C2C3. Explain how he can modify the message so that the amount is transferred to his own account. b. Explain how the use of a MAC would prevent this attack. c. Above, E(K, M) denotes using block cipher E with key K on message M. It is possible to define a cipher using similar ideas, but using a hash function instead. Describe how to do it, including how to decrypt.

Some of your friends have gotten into the burgeoning field of time-series data mining, in which one looks for patterns in sequences of events that occur over time. purchases at stock exchanges--what’s being bought-- are one source of data with a natural ordering in time. given a long sequence s of such events, your friends want an efficient way to detect certain "patterns" in them--for example, they may want to know if the four events buy yahoo, buy ebay, buy yahoo, buy oracle occur in this sequence s, in order but not necessarily consecutively. they begin with a collection of possible events (e.g., the possible’ transactions) and a sequence s of n of these events. a given event may occur multiple times in s (e.g., yahoo stock may be bought many times in a single sequence s). we will say that a sequence s’ is a subsequence of s if there is a way to delete certain of the events from s so that the remaining events, in order, are equal to the sequence s’. so, for example, the sequence of four events above is a subsequence of the sequence buy amazon, buy yahoo, buy ebay, buy yahoo, buy yahoo, buy oracle their goal is to be able to dream up short sequences and quickly detect whether they are subsequences of s. so this is the problem they pose to you: give an algorithm that takes two sequences of even~s--s’ of length m and s of length n, each possibly containing an event more than once--and decides in time o(m n) whether s’ is a subsequence of s

What best describes a career pathway in a lodging career? a worker starts out as an amusement attendant, then becomes a recreation worker, and then becomes a gaming worker within five years. a worker starts out as a bell hop, then becomes a night clerk, and then becomes a hotel manager within five years. a worker starting out as a tour guide, then becomes a travel clerk, and then becomes a travel agent within five years. a worker starts out as a server, then becomes a food preparer, and then becomes a head chef within five years.

Aplan to budget time for studying and activities is referred to as a study routine. study habits. study skills. a study schedule.