Q5. Designing a Secure Authentication Protocol for a One-to-One Secure Messaging Platform (Marks: 10) (a) Analysing the

[answerhappygod]

Q5 Designing A Secure Authentication Protocol For A One To One Secure Messaging Platform Marks 10 A Analysing The 1 (109.47 KiB) Viewed 45 times

Q5. Designing a Secure Authentication Protocol for a One-to-One Secure Messaging Platform (Marks: 10) (a) Analysing the security strength of authentication protocols (Marks: 7.5) Assume that you have been hired to design a secure mutual authentication and key establishment protocol for a new messaging software. In the software, two users (ex: Alice and Bob) needs to exchange messages using timestamp (7) and public-key cryptography based mutual authentication protocol to achieve mutual authentication and establish a secure session key (K) before the start of the conversation as shown in Figure-3. According to the given scenario, Alice and Bob should exchange two messages to achieve mutual authentication and establish the secure session key (K). As the mutual authentication protocol involves timestamp (7), the replay attack can be ignored. Assume that Alice is the initiator of the communication. Alice sends "Message 1" to Bob and Bob always replies with "[T+1] Bob". Message 1 [T+1] Bob Alice Bob Figure-3: Overview of the secure mutual authentication and key establishment protocol You have options to choose from several protocols and analyzing their security strength. The prospective security protocols are as follows: i. In protocol-1, Message 1: {[T, K]Alice/Bob ii. In protocol-2, Message 1: {"Alice", [T, K]Alice}Bob iii. In protocol-3, Message 1: "Alice", {[T, K] Alice/Bob iv. In protocol-4, Message 1: T, "Alice", {[K]Alice}Bob v. In protocol-5, Message 1: "Alice", {[T]Alice}Bob and let K=h(T) In this task, you need to critically analyze the above protocols and clearly explain which protocol or protocols would be secured and why. Notations are summarized below: к :Session key T : Timestamp T+1 : Timestamp is increased by 1 h(T) : Hash of timestamp T : Encryption Function that encrypts "Message" using Bob's public Key {"Message"}Bob ["Message"]Alice : Encryption Function that encrypts "Message" using Alice's private Key which is also known as signed "Message" by Alice