Assignment 2 – Due Tuesday, September 12

  1. Textbook, Exercise 2.7

  2. Textbook, Exercise 2.12 – note that this encryption scheme is a generalization of the “Double OTP” scheme from page 34, where we’re using a generic scheme instead of specifically using OTP. The proof is structured similarly to Claim 2.13, although the goal is one-time secrecy rather than one-time uniform ciphertexts.

  3. Textbook, Exercise 2.14 (hint: one direction of the if-and-only-if is almost identical in structure to the proof of Theorem 2.15 in the book)

  4. Textbook, Exercise 3.1

  5. Textbook, Exercise 3.8

  6. A group is sharing a one-byte secret \(s\) using a 2-of-12 version of Shamir’s secret sharing scheme with modulus \(p=257\) (the first prime greater than 255). You have captured two secrets: (2,37) and (5,158). What is \(s\)? Show your work!