ABSTRACT
Setup: The key-generation center (KGC) generates two large primes p and q such that q|p − 1 and selects a generator g from the group Z∗p. After that, the KGC picks x ∈ Z∗p uniformly at random and computes y = gx. Then, the KGC chooses hash functions H1 : {0, 1}∗ × Z∗p × Z∗p → Z∗p, H2 : {0, 1}l0 × {0, 1}l1 → Z∗p, and H3 : Z∗p → {0, 1}l, where l = l0 + l1 ∈ N. Finally, the KGC publishes the public parameters params =(p, q, g, y,H1, H2, H3) and keeps master-key = x secret.
