Mod
11
Calculator
Arithmetic in a prime field, with the work shown. Everything reduces to the range 0 to p − 1.
Vigenère Cracking Lab
Diffie-Hellman Playground
Modulus
Any prime. The worksheets use 11.
p =
11
13
17
23
101
Expression
Use + − × ÷ ^ and parentheses. Division means multiplying by the inverse.
Compute
Polynomial
Evaluate f(x) at x = 1, 2, …, n. Each term is reduced separately, as on the worksheet.
Coefficients, constant term first:
up to x =
Recover a secret
Lagrange interpolation at x = 0 from T shares. Each product is shown before it is reduced.
Shares as x,y pairs:
Tables
Shown for p up to 31. The 1s in the multiplication table mark inverse pairs.
Multiplication, row × column
Powers a
k
, row a, column k
Inverses
Tables are hidden for p larger than 31. The calculators above still work.