# Security of key bits under indistinguishability for randomized encryption

My question is about symmetric randomized encryption. Let c=E(k,m,r) be a randomized block encryption function where r denotes a random input chosen for each message block m. k and c denote the symmetric key and ciphertext respectively. If E has indistinguishability of m0, m1 for any chosen plaintexts by an adversary given a chphertext c of mb for a randomly chosen bit b, how does this translate to security of key k given ci for any chosen plaintexts mi by allowing oracle access to the adversary? In the deterministic encryption there is the security condition that the computation of k given p,c is infeasible. How is this property assured by indistinguishability?