Online Survey A queries the subject's demographic information, educational attainment, occupational history, living situation before death, athletic history (type of sports played, level, position, age of first exposure, and duration), and military history (branch, location of service, and duration of combat exposure).
It is clear that A. Let AskH denote the event that A queries random oracle H on (pw, x2, C, G, n, e, n', e', r1, r2, y2).
(mathcal A ) queries the trapdoor generation oracle Trapdoor to obtain the trapdoor (T_w={mathtt Trapdoor} sk,w)) for the corresponding keyword (w) of his choice.
It keeps (sk) and gives (pk) to the adversary (mathcal A.) (mathcal A ) queries the trapdoor generation oracle Trapdoor to obtain the trapdoor (T_w={mathtt Trapdoor} sk,w)) for the corresponding keyword (w) of his choice.
Let AskH1,2 denote the event that A queries random oracle H1 on (x1, C, G, n, e, n', e', r1, r2, y2,z, c1) or H2 on (x1, C, G, n, e, n', e', r1, r2, y2, z, c1, c2), while AskH does not happen.
If event AskH happens, which means A queries random oracle H on (pw, x2, C, G, n, e, n', e', r1, r2, y2), where x 2 e = x e ⋅ c mod n, then we can decrypt c by x2/x mod n.
