Question

Now, suppose Alice and Bob use random numbers to enhance security. Alice signs the combination of message MI-This is Alice" and a random number R1, then send M1, R1, and digital signature to Bob; and Bob does the similar thing. Is this secure? 9. M1- "This is Alice", R1, Alice_Sign(M1, R1) Alice Bob M2 "This is Bob", R2, Bob_Sign(M2, R2)

Answer 1

yes this kind of communication is secure because in this digital sign is used . hence when alice send message m1 with a random number r1 using digital signature to bob . by using digital signature this messgae become end to end secure .so that in between no hacker or attacker can get to know what was there in that message even if message is stolen it will not be readby third party / hacker /fake user . and in same manner bob replies which is secure .another method can be encryption in which simple text message is converted to secret/ciper text which can only be read by using keys which are owned by sender and real receiver this method also increases security