A and B want to establish a secure communication channel between them. They do not care about the confidentiality of the messages being transmitted, but they do want to ensure the integrity and authenticity of the messages. Answer the following questions by drawing diagrams that show the procedures of sending and receiving messages. Assume A and B share a common key K. a. How can they achieve their goal only with secret key cryptography

Ted wants to go out to a neighborhood park and shoot pictures of dew drops on grass. he wants to get a low-level angle of the dew drops. which support equipment should ted use? a. mini tripod b. pistol grip c. monopod d. body mount

You will be given two character arrays of the same size, one will contain a number of ships. ships will move around the character array based on which way they are facing and the route they are on. routes are given in the other array. the route consists of '-' and '|' for straight paths, '\' and '/' for curves, and '+' for intersections. there are ships on these routes. ships always face a direction, '^' for up, '> ' for right, 'v' for down, and '< ' for left. any time the ships hit a '\' or a '/' it will turn as you would expect a ship to turn (e.g. a '^' that moves into a '/' will turn right). at an intersection, ships will always continue straight through. all ships move at the same speed, ships take turns moving and all ships move during one 'tick'. the one in the most top left goes first, followed by those to its right, then the ones in the next row. it iterates along the rows and then down the columns. each ship moves one space on its turn moving along the route. your function needs to return the position of the first collision between two ships and the number of ticks before the crash occurred.

David is in week 3 of his current ashford course and has a paper due by monday night at midnight. he has finished everything but the concluding paragraph. as he boots up his computer to work on it, he sees a flash across the screen and then the screen goes black. he begins to panic as he tries desperately to turn the laptop back on. david should have saved his work on what kind of portable device?