Cybersecurity document Part 1, 2 or 3

Question 3: Protocol Design and Analysis You are a reporter who is meeting a potential whistle-blower in person, in an effort to establish subsequent communication. The two of you are currently sitting back to back in a busy park bench, where he agrees to collaborate. During the encounter, he gives you a business card with his email and a secret 10-digit number, while you provide him with a SHA-3 hash digest of your public key. You further agree on the following protocol: The informant will wait for your initial contact and subsequent requests for certain documents. You should not assume that any trusted-third party could assist you in this situation; you will never meet in person again. 1. Identify and justify a realistic threat model for the described scenario, i.e.: • who are the adversaries • what are their goals (or what do you want the protocol to protect against) • what are their capabilities/constraints (a good answer would probably take at most 1 page) 2. Should the 10-digit number be used as a symmetric secret key? Explain your reasoning. (a good answer would probably take at most half a page) 3. Propose your own authentication and data transfer protocol to be used between you and the informant. Make sure you justify your design decisions. Identify and discuss security implications of your design. (a good answer would probably take at most 3 to 4 pages) Note: use the notation introduced in the class; remember