With Trusted Third Party -Version 2 Alice A Bob n Authentication (n,B)KA Center A,{n,BKA→ nKB Question:Is this authentication protocol secure? -Answer:No. 88 With Trusted Third Party – Version 2  Question: Is this authentication protocol secure? ─ Answer: No. Alice A Bob n {n, B}KA A, {n, B}KA {n}KB Authentication Center