Day 12 in Mat115

Today:

• Next time: Collect homework for sections 2.2 and 2.3

• This time: Public Codes, with the Kelly(ie)s!

• Possibilities:
  • Cryptography -- the study of secret codes

  • RSA:
    • pq - public product of two huge primes, perhaps 200 digits each.

    • glabrous: having no hair or similar growth; smooth; "glabrous stems"; "glabrous leaves"; "a glabrous scalp"

    • Fermat's little theorem:

      If p is a prime number and n is any integer that does not have p as a factor, then n^p-1 is equal to 1 mod p.

      In other words, n^p-1 will always have a remainder of 1 when divided by p.

    • How many atoms in the universe? How many digits in a number of 100 digits raised to the 100th power?

      What is 23²⁶³⁹ mod 13?

      (Use Fermat's little theorem!)

Links:

• lisp code for a sample case