sacred-4----Page:4
1  2  3  4  5  6  7  8  9 

OPAKE: Setup
Assume that pw is mapped to an n-bit long codeword (via an error-correcting code of distance d)
from now on when we talk about password, we really mean the encoded password
Assume a known 2 x n table of small primes
Let D = product of primes associated with password bits (yellow)
Let R = product of primes associated to complement of password (white)
Server will construct modulus N = PQ (P,Q large primes) such that: D | F(N), but gcd(R,F(N))=1
Note that F(N) is the order of multiplicative group modulo N, and there is a subgroup of order D in which discrete logarithms are easy
Example:
pw=1011000…1
PPT Version