I A Signcryption Approach Based on Rabin Digital Signature Schemes التوقيع والتشفير القائم على التوقيع الرقمى رابين Prepared By Ali Mohammad Alzeinat Supervisor Dr. Ahmad Abu-Shareha Thesis Submitted In Partial Fulfillment of the Requirements for the Degree of Master of Computer Science Department of Computer Science Faculty of Information Technology Middle East University June- 2017 II III IV V Acknowledgments First, I give thanks, praise to Allah for his mercy, and reconcile and for granting me knowledge, confidence, patience to pass this Master thesis successfully. Also, I would like to express my thank to my thesis advisor. DR. Ahmed Adel Abu-Shareha for the complete guidance throughout the thesis stages, and for the critical assistance in designing and proceeding the methodology of my research. Finally, I would like to acknowledge my friends Mustafa Awad Farhan and Qasem Abu Jabal who have supported me through entire process. I will be grateful forever for your love. VI Dedication VII Table of Content COVER Page................................................................................................................... I AUTHORIZATION STATEMENT .................................................................................................................... I .ERROR! BOOKMARK NOT DEFINED ........................................................................................... إقرار تفويض EXAMINATION COMMITTEE DECISION ................................................... ERROR! BOOKMARK NOT DEFINED. ACKNOWLEDGMENTS .............................................................................................................................. IV DEDICATION ............................................................................................................................................ VI TABLE OF CONTENT................................................................................................................................. VII LIST OF TABLES ......................................................................................................................................... X LIST OF FIGURES ........................................................................................................................................ X LIST OF SYMBOLS ...................................................................................................................................... X LIST OF ABBREVIATIONS ........................................................................................................................ XIII ABSTRACT ............................................................................................................................................... XV XVII ................................................................................................................................................. ال ُملخص CHAPTER ONE: INTRODUCTION ................................................................................................................. 1 1.1 INTRODUCTION ................................................................................................................................................... 2 1.2 CRYPTOGRAPHY .................................................................................................................................................. 3 1.3 DIGITAL SIGNATURE (DS) ..................................................................................................................................... 4 1.3.1 RSA Digital Signature .................................................................................................................................. 5 1.3.2 Rabin Digital Signature ................................................................................................................................ 6 1.3.3 Hash Function H(.) ....................................................................................................................................... 7 1.4 SIGNCRYPTION .................................................................................................................................................. 10 1.4.1 Signature-Then-Encryption ....................................................................................................................... 10 1.4.2 Signcryption Technique ............................................................................................................................ 12 1.4.3 Signcryption and Security Concerns ......................................................................................................... 14 1.5 PROBLEM STATEMENT ....................................................................................................................................... 16 1.6 RESEARCH QUESTIONS .......................................................................................................................... 16 1.7 GOAL AND OBJECTIVES.......................................................................................................................... 16 VIII 8.1MOTIVATION ............................................................................................................................................. 17 1.9 CONTRIBUTION AND SIGNIFICANCE OF THE RESEARCH .............................................................................................. 18 1.10 SCOPE OF THE STUDY ....................................................................................................................................... 18 1.11 THESIS OUTLINES ............................................................................................................................................ 18 CHAPTER TWO: THEORETICAL BACKGROUND AND RELATED WORK ......................................................... 20 2.1 OVERVIEW ....................................................................................................................................................... 21 2.2 INTRODUCTION ................................................................................................................................................. 21 2.3 BACKGROUND .................................................................................................................................................. 22 2.3.1 Public Key Algorithms ............................................................................................................................... 22 2.3.2 Digital Signature Algorithms (DSA) ........................................................................................................... 24 2.4 RELATED WORK ................................................................................................................................................ 27 2.4.1 El-Gamal-Based Signcryption .................................................................................................................... 27 2.4.2 Bao and Deng Signcryption Scheme ......................................................................................................... 31 2.4.3 Elliptic Curve-based Signcryption Scheme ................................................................................................ 33 2.4.4 RSA-based Signcryption ............................................................................................................................ 37 2.4.5 Diffie-Hellman Based Signcryption Scheme.............................................................................................. 38 2.4.6 Proxy Signcryption .................................................................................................................................... 38 2.4.7 ID-Based Signcryption ............................................................................................................................... 40 2.4.8 Hybrid Signcryption Scheme ..................................................................................................................... 41 2.4.9 Schnoor Based Syncryption ...................................................................................................................... 42 0.14. 2Comparison ............................................................................................................................. 44 2.5 RABIN CRYPTOSYSTEM ....................................................................................................................................... 46 2.6 SUMMARY ....................................................................................................................................................... 49 CHAPTER THREE: PROPOSED WORK ........................................................................................................ 51 3.1 OVERVIEW ....................................................................................................................................................... 52 3.2INTRODUCTION .................................................................................................................................................. 52 3.3SOLVING RABIN CRYPTOSYSTEM PROBLEM .............................................................................................................. 53 3.4 RABIN CRYPTOSYSTEM ANALYSIS FOR SIGNCRYPTION ............................................................................................... 55 5.3THE PROPOSED SIGNCRYPTION BASED ON RABIN CRYPTOSYSTEM .......................................................................