Please refer to this secure index paper. On page#6, a
trapdoor is defined as
Trapdoor(Kpriv, w): Given the master key Kpriv = (k1, … , kr) and word w, output the trapdoor for word w as: Tw = (f(w, k1), … , f(w, kr))
Can someone please explain it to me using an example?
Let's say we've a word hello for which we want to generate a trap door. So, do I first encrypt it with
k1 and then take its hash. And do the same with key k2, k3 etc. Once we have all the hashes, simple concatenate them. Is my understanding correct?