With Trusted Third Party-Version 3 Alice A Bob n Authentication (n,B)KA Center A,{n,BKA→ Symmetry is not goodn A'KB Question:Is this authentication protocol secure? Answer:No. Hint:message symmetry in authentication protocols is not good. 1010 With Trusted Third Party – Version 3  Question: Is this authentication protocol secure? ─ Answer: No.  Hint: message symmetry in authentication protocols is not good. Alice A Bob n {n, B}KA A, {n, B}KA {n, A}KB Authentication Center Symmetry is not good