1. trusting others with personal and private information

Email viruses are typically launched by people who modify header information to hide their identity. brightmail's enrique salem says that in the future, your email reader will authenticate the sender before putting hte message in your inbox. that way, you will know the source of all the emails you read. alan nugent of novell says, "i'm kind of a fan of eliminating anonymity if that is the price for security." will eliminating anonymity make computers more secure?

Problem 3: access control pokeygram, a cutting-edge new email start-up, is setting up building access for its employees. there are two types of employees: managers and engineers, and there are three departments: security, networking, and human resoures. each employee works in a single department, and each department is housed on a different floor. managers are allowed access to any floor, while engineers are allowed access only to their own floor. there are three badge-operated elevators, each going up to only one distinct floor. every employee has one badge. pokeygram wants to use the best possible access control method in order to minimize delay for the elevators (a) access control matrix, 1. which of the following would you recommend that pokeygram use: (b) access control lists, or (c) capabilities? make sure to justify your answer. 2. what, if any, would be the benefits (and/or disadvantages) of using rbac (role-based access control) in this situation? keep your solution for this problem limited to 10-12 lines of text.

Suppose that a major city’s main thoroughfare, which is also an interstate highway, will be completely closed to traffic for two years, from january 2014 to december 2015, for reconstruction at a cost of $535 million. if the construction company were to keep the highway open for traffic during construction, the highway reconstruction project would take much longer and be more expensive. suppose that construction would take four years if the highway were kept open, at a total cost of $800 million. the state department of transportation had to make its decision in 2014, one year before the start of construction (so that the first payment was one year away). so the department of transportation had the following choices: (i) close the highway during construction, at an annual cost of $267.5 million per year for two years. (ii) keep the highway open during construction, at an annual cost of $200 million per year for four years. now suppose the interest rate is 80%. calculate the present value of the costs incurred under each plan.