We have a n (Gen, Enc, Dec) encryption scheme with message space M-10,1] and n (Gen', Enc, Dec') to be an encryption scheme with M-10,1)2(view it as 2 n-bit m1,m2). For Gen'(1"), k-.Gen(ln). +' For Enck,(m1,m2), C1-.Ena(m1 ), c2-.Eng(m2). . For Deck,(c1,c2), m1-.Deck'(c1), m2-n.Deck'(e2), if m1-1 = L, retum L, else return ml m2. 4 (1) If is CPA-secure, is . CPA-secure? Why?.. (2) If is CCA-secure, is . CCA-secure? Why?.. or m 2 We have a n (Gen, Enc, Dec) encryption scheme with message space M-10,1] and n (Gen', Enc, Dec') to be an encryption scheme with M-10,1)2(view it as 2 n-bit m1,m2). For Gen'(1"), k-.Gen(ln). +' For Enck,(m1,m2), C1-.Ena(m1 ), c2-.Eng(m2). . For Deck,(c1,c2), m1-.Deck'(c1), m2-n.Deck'(e2), if m1-1 = L, retum L, else return ml m2. 4 (1) If is CPA-secure, is . CPA-secure? Why?.. (2) If is CCA-secure, is . CCA-secure? Why?.. or m 2