"Guide for the Perplexed" http://en.wikipedia.org/wiki/The_Guide_for_the_Perplexed /--------------------------------------------------------\ Dear Number-theory Cryptographic Enthusiasts (Spring 2013) For Monday's exam, in addition to everything else, you should know, cold: * How to solve all the quiz problems on http://math.ufl.edu/~squash/NT/NT2013g/quizzes-Cryp.2013g.pdf that are relevant to what we've covered so far. * How to precisely STATE, and rigorously PROVE: FLiT; EFT; Wilson's Thm [involution ideas]; Legendre Symbol Thm (LST) parts (a,b,c) -and you should be able to state part (d). [More involution ideas.] Note that if you use a term, e.g, "8Near", you must be able to rigorously /define/ it. CRT. Applications of CRT to finding roots of polynomials. To speeding up RSA. The Fusion Algorithm, and prove why it works. All of the DEFINITIONS and material in: http://math.ufl.edu/~squash/PrNt/nt-review.pdf except for the irreducible/prime distinction. That the multiplicative group of a finite field is cyclic. Be able to compute a generator for Phi(p), when p is a small prime, e.g p<40. How to prove, for a codeword set, that weak-UD implies UD. * Know how to state: Kraft-McMillan Thm. The thm characterising the SOTS primes. The thm characterising the cyclicish numbers. * Know the defn of: (Totally) Multiplicative fnc, and several examples. Semigroup. Group. Abelian group. Ring. Commutative ring. Field. Know examples of each that is not an example of the next. Zero-divisor in a ring; unit in a ring. Cyclic group. Cartesian product of groups. Know examples of finite groups which are not cyclic. Short certificate of . Be able to give an example of a short certificate of compositeness, of primeness. Defn of "group-isomorphism", "ring-isomorphism", "ring-homomorphism". Mod-N primitive root. Can apply the methods in: http://math.ufl.edu/~squash/PrNt/lightning-bolt.pdf http://math.ufl.edu/~squash/PrNt/nt-algorithms.pdf http://math.ufl.edu/~squash/PrNt/chinese-rem-thm.pdf http://math.ufl.edu/~squash/NT/chinese-RT.txt http://math.ufl.edu/~squash/NT/fuse-example.txt http://math.ufl.edu/~squash/NT/fibonn.txt http://math.ufl.edu/~squash/PrNt/jk-codes.pdf (except the entropy/distropy part.) * Know how to rapidly implement the algorithms (that is, be able to APPLY the algorithm, and also be able to rigorously DESCRIBE the algorithm) for: Know how to compute the mult-order of an elt in Phi(N). Know how to compute Euler phi, and the Legendre symbol. Encode/decode with affine-codes, breaking an affine-code given some plaintext with coded value. Repeated-squaring. LBolt. Constructing Huffman codes. Given a probability distribution, counting the number of Huffman trees, isomorphism classes of Huffman tress, the number of Huffman codes. Know how to compute the MECL of a probability distribution. [Hint: Compute a Huffman code, then compute it ECL.] * Know the mathematical description of: RSA. Discrete-Logarithm Problem (DLP). Diffie-Hellman (DHP), ElGamal (EGP). Be able to compute examples of each encode/decode/create. Defn of "polynomial-time reducible" (one problem to another). Know how to prove that EGP and DHP are polytime equivalent, and each is polytime reducible to DLP. \________________________________________________________/