This morning, your coworker decided to implement the stateless encryption scheme based on PRFs that they learned about in their crypto course. But since the course was a while back, they didnt remember exactly how the scheme went. They ended up with the following candidates. Can you help your coworker, by picking one of these candidates and proving that it is corect and t-SS-CPA secure for any t() that is polynomial in ? In all of these schemes, the key k and the encryption randomness r are chosen at random from {0,1}, the message space is M={0,1},F is a PRF with keyspace, domain and range {0,1}, and denotes bitwise exclusive or. - Enc(k,m)=(r,F(r,k)m) - Enc(k,m)=(r,F(m,(k,r)) (here the domain of F is {0,1}2) - Enc(k,m)=(r,F((k,r)(rm) (here the keyspace of F is {0,1}2) - Enc(k,m)=(r,F(k,r)rm) - Enc(k,m)=(r,F(k,kr)m)