Secure Instant Messenger in Android Name: Shamik Roy Chowdhury.

Slides:

Advertisements

Similar presentations

Chapter 3 Public Key Cryptography and Message authentication.

Advertisements

Hash Functions A hash function takes data of arbitrary size and returns a value in a fixed range. If you compute the hash of the same data at different.

Spring 2000CS 4611 Security Outline Encryption Algorithms Authentication Protocols Message Integrity Protocols Key Distribution Firewalls.

Internet and Intranet Protocols and Applications Lecture 9a: Secure Sockets Layer (SSL) March, 2004 Arthur Goldberg Computer Science Department New York.

Topic 7: Using cryptography in mobile computing. Cryptography basics: symmetric, public-key, hash function and digital signature Cryptography, describing.

Cryptographic Security CS5204 – Operating Systems1.

Authentication and Digital Signatures CSCI 5857: Encoding and Encryption.

Network Security – Part 2 Public Key Cryptography Spring 2007 V.T. Raja, Ph.D., Oregon State University.

ECOMMERCE TECHNOLOGY SUMMER 2002 COPYRIGHT © 2002 MICHAEL I. SHAMOS Cryptographic Security.

BY MUKTADIUR RAHMAN MAY 06, 2010 INTERODUCTION TO CRYPTOGRAPHY.

Cryptographic Techniques Instructor: Jerry Gao Ph.D. San Jose State University URL: May,

ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Cryptography.

Symmetric Key Distribution Protocol with Hybrid Crypto Systems Tony Nguyen.

Cryptographic Technologies

Henric Johnson1 Chapter3 Public-Key Cryptography and Message Authentication Henric Johnson Blekinge Institute of Technology, Sweden

ITIS 3200: Introduction to Information Security and Privacy Dr. Weichao Wang.

WS Algorithmentheorie 03 – Randomized Algorithms (Public Key Cryptosystems) Prof. Dr. Th. Ottmann.

Electronic mail security -- Pretty Good Privacy.

Introduction to Public Key Infrastructure (PKI) Office of Information Security The University of Texas at Brownsville & Texas Southmost College.

Network Security – Part 2 V.T. Raja, Ph.D., Oregon State University.

Information Security. Information Security Requirements Confidentiality: Protection from disclosure to unauthorised persons Access control: Unauthorised.

Overview of Digital Signatures Introduction To Networks and Communications (CS 555) Presented by Bharath Kongara.

Encryption Methods By: Michael A. Scott

CRYPTOGRAPHIC DATA INTEGRITY ALGORITHMS

Chapter 8.  Cryptography is the science of keeping information secure in terms of confidentiality and integrity.  Cryptography is also referred to as.

Cryptographic Security Cryptographic Mechanisms 1Mesbah Islam– Operating Systems.

Encryption is a way to transform a message so that only the sender and recipient can read, see or understand it. The mechanism is based on the use of.

Digital Signature Xiaoyan Guo/ Xiaohang Luo/

Security using Encryption Security Features Message Origin Authentication - verifying that the sender is who he or she says they are Content Integrity.

CS5204 – Fall Cryptographic Security Presenter: Hamid Al-Hamadi October 13, 2009.

1 Public-Key Cryptography and Message Authentication Ola Flygt Växjö University, Sweden

©Brooks/Cole, 2003 Chapter 16 Security. ©Brooks/Cole, 2003 Define four aspects of security in a network: privacy, authentication, integrity, and nonrepudiation.

Page 1 Secure Communication Paul Krzyzanowski Distributed Systems Except as otherwise noted, the content of this presentation.

Pretty Good Privacy by Philip Zimmerman presented by: Chris Ward.

Electronic Mail Security

Secure r How do you do it? m Need to worry about sniffing, modifying, end- user masquerading, replaying. m If sender and receiver have shared secret.

Network Security – Part 2 (Continued) Lecture Notes for May 8, 2006 V.T. Raja, Ph.D., Oregon State University.

© 2006 Cisco Systems, Inc. All rights reserved. Network Security 2 Module 3: VPN and Encryption Technology.

ECE509 Cyber Security : Concept, Theory, and Practice Cryptography Spring 2014.

Security.  is one of the most widely used and regarded network services  currently message contents are not secure may be inspected either.

Cryptography  Why Cryptography  Symmetric Encryption  Key exchange  Public-Key Cryptography  Key exchange  Certification.

Cryptography, Authentication and Digital Signatures

4 th lecture.  Message to be encrypted: HELLO  Key: XMCKL H E L L O message 7 (H) 4 (E) 11 (L) 11 (L) 14 (O) message + 23 (X) 12 (M) 2 (C) 10 (K) 11.

BASIC CRYPTOGRAPHIC CONCEPTS. Public Key Cryptography  Uses two keys for every simplex logical communication link.  Public key  Private key  The use.

Cryptography Wei Wu. Internet Threat Model Client Network Not trusted!!

Chapter 16 Security Introduction to CS 1 st Semester, 2012 Sanghyun Park.

11-Basic Cryptography Dr. John P. Abraham Professor UTPA.

Symmetric Cryptography, Asymmetric Cryptography, and Digital Signatures.

Advanced Database Course (ESED5204) Eng. Hanan Alyazji University of Palestine Software Engineering Department.

Privacy versus Authentication Confidentiality (Privacy) –Interceptors cannot read messages Authentication: proving the sender’s identity –The Problem of.

31.1 Chapter 31 Network Security Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1 CMPT 471 Networking II Authentication and Encryption © Janice Regan,

Security Using PGP - Prajakta Bahekar. Importance of Security is one of the most widely used network service on Computer Currently .

Secure Messenger Protocol using AES (Rijndael) Sang won, Lee

© Copyright 2009 SSLPost 01. © Copyright 2009 SSLPost 02 a recipient is sent an encrypted that contains data specific to that recipient the data.

Electronic Mail Security Prepared by Dr. Lamiaa Elshenawy

CS426Fall 2010/Lecture 51 Computer Security CS 426 Lecture 5 Cryptography: Cryptographic Hash Function.

Network Security Celia Li Computer Science and Engineering York University.

CIA AAA. C I A Confidentiality I A Confidentiality Integrity A.

Copyright 2004 MayneStay Consulting Group Ltd. - All Rights Reserved Jan-041 Security using Encryption Security Features Message Origin Authentication.

Cryptographic Security Aveek Chakraborty CS5204 – Operating Systems1.

Security By Meenal Mandalia. What is ? stands for Electronic Mail. much the same as a letter, only that it is exchanged in a different.

M2 Encryption techniques Gladys Nzita-Mak. What is encryption? Encryption is the method of having information such as text being converted into a format.

CRYPTOGRAPHY Cryptography is art or science of transforming intelligible message to unintelligible and again transforming that message back to the original.

Fundamentals of Network Security Ravi Mukkamala SCI 101 October 6, 2003.

Cryptographic Hash Function. A hash function H accepts a variable-length block of data as input and produces a fixed-size hash value h = H(M). The principal.

Cryptographic Hash Function

e-Health Platform End 2 End encryption

Chapter -7 CRYPTOGRAPHIC HASH FUNCTIONS

10/7/2019 Created by Omeed Mustafa 1 st Semester M.Sc (Computer Science department) Cyber-Security.

Presentation transcript:

Secure Instant Messenger in Android Name: Shamik Roy Chowdhury

What happens when 2 parties communicate STEP 1: Key Generation + Exchange : Each party generates 2048-bit RSA Public/Private key-pair. Each party exchange their public key with each other. Any one party generates 128-bit AES Symmetric Key, encrypts it with public key received from the other party and sends this encrypted symmetric key to other party. Other party on receiving the encrypted symmetric key, decrypts it with its own Private Key. At this stage both parties have the AES 128-bit Symmetric key.

What happens when 2 parties communicate STEP 2 : Sending a Message (Encryption Process): Party A wants to send a message to Party B. Party A applies ‘SHA-256’ hashing algorithm on the message getting a message digest. The Message Digest is encrypted with the RSA Private Key generating a digital signature. The (Message + RSA Private Key Encrypted Message Digest) is encrypted with the AES Symmetric Key. Then sent to other party.

What happens when 2 parties communicate STEP 3.1 : Message Received (Decryption Process) : Party B receives [AES Encrypted (Message + RSA Private Key Encrypted Message Digest)]. Decryption with AES Symmetric Key gives (Message + RSA Private Key Encrypted Message Digest). Party B applies RSA Public Key.. (received from the other party during the key exchange process).. to decrypt the encrypted Message Digest.

What happens when 2 parties communicate STEP 3.2 : Message Received (Message Authentication) Generate ‘SHA-256’ Message Digest of decrypted Message via ‘SHA-256’ hashing algorithm. Compare the generated ‘SHA-256’ Message Digest to the one received from other party and recovered. Message authenticated if both the message digests match.

Achieving Security while sending and receiving a chat message

Demonstration

Achieving Security while sending and receiving a chat message AES Symmetric Key Encryption provides data confidentiality. Hash Code of Message encrypted with sender’s Private Key providing a digital signature.. (since only the sender could have produced the encrypted hash code). Even if the attacker came to know of the symmetric key, in order to alter the message and get away with it, he would have to know the sender’s private key. Generation of (hash code + digital signature) provides a mechanism to provide secure message authentication. Stronger the symmetric key encryption process, greater the achievement of data integrity.

Benefits of the Cryptographic Algorithms used Benefits of RSA : – Public Key encryption. (Public key encrypted text can only be decrypted by the intended recipient, by using the private key, (private key known only to intended recipient)). – AES Symmetric Key securely exchanged between 2 parties using this procedure. Benefits of AES algorithm over other encryption algorithms : – High Efficiency. – Not Complex. – High Security. Benefits of using SHA-256 : – Fast Hashing Algorithm – Secure