(Chosen Ciphertext Security). Let E=(G2E,D) be a public-key encryption over (M,C). a) Describe the security game of IND-CCA security (hints: slides p22 ) b) Suppose an active attacker can convert the ciphertext of m1= (to: caroline@gmail, body) to the ciphertext of m2=( to: attack@gmail,body), i.e., given c1=E(sk,m1), the attacker can obtain c2=E(sk,m2), Following the slides p23, show that this encryption algorithm is not CCA secure..

1. (Chosen Ciphertext Security). Let E=(G2E,D) be a public-key encryption over (M,C). a) Describe
the security game of IND-CCA security (hints: slides p22 ) b) Suppose an active attacker can
convert the ciphertext of m1= (to: caroline@gmail, body) to the ciphertext of m2=( to:
attack@gmail,body), i.e., given c1=E(sk,m1), the attacker can obtain c2=E(sk,m2), Following the
slides p23, show that this encryption algorithm is not CCA secure.