it generates a random value r from
some appropriate set, and deterministically computes messages m(r)
0 , m(r)
1 , which depend on r, and
evaluates a predicate "(r) on c, which also depends on r. Here, semantic security says that the value
✏ in (2.6), with m0,m1," replaced by m(r)
0 ,m(r)
1 ,"(r), is negligible — but where now the probability
is with respect to a randomly chosen key and a randomly chosen value of r.