Rabin’s scheme

• View each string A as a polynomial over Z2:

  A = 1 0 0 1 1 ? A(x) = x4 + x + 1
  

• Let P(t) be an irreducible polynomial of degree k chosen uar

• The fingerprint of A is

  f(A) = A(t) mod P(t)
  

• The probability of collision among n strings of average length t is about

  n^2 t / 2^k
  

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