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CRYPTOGRAPHY AND INFORMATION SECURITY. Lecturer: Dr. Nguyen Nam Hong Tel.: 048781437. Mobi.: 0912312816. Email: nguyennamhong2003@yahoo.com.au Website: www.freewebs.com/namhongthanhloc. COURSE CONTENTS (1/4). 1. Introduction 2. Classical Encryption Techniques 3. Block Cipher
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CRYPTOGRAPHY AND INFORMATION SECURITY Lecturer: Dr. Nguyen Nam Hong Tel.: 048781437. Mobi.: 0912312816. Email: nguyennamhong2003@yahoo.com.au Website: www.freewebs.com/namhongthanhloc
COURSE CONTENTS (1/4) 1. Introduction 2. Classical Encryption Techniques 3. Block Cipher 4. Data Encryption Standard (DES) 5. Finite Fields 6. Advanced Encryption Standards 7. Contemporary Symmetric Cipher Dr. Nguyen Nam Hong, Le Quy Don Technical University
COURSE CONTENTS (2/4) 8. Confidentiality Using Symmetric Encryption 9. Introduction to Number Theory 10. Public Key Cryptography and RSA 11. Key Management – Other Public Key CryptoSystems 12. Message Authentication and Hash Functions Dr. Nguyen Nam Hong, Le Quy Don Technical University
COURSE CONTENTS (3/4) 13. Hash Algorithms 14.Digital Signatures and Authentication Protocols 15. Authentication Applications 16. Electronic Mail Security 17. IP Security 18. Web Security Dr. Nguyen Nam Hong, Le Quy Don Technical University
COURSE CONTENTS (4/4) 19. Intruders 20. Malicious Software 21. Firewall Dr. Nguyen Nam Hong, Le Quy Don Technical University
REFERENCES (1/2) 1. W. Stallings, “Cryptography and Network Security”, CRC Press, 1996. 2. Stinson D.R.: Cryptography Theory and Practice, CRC Press, 1995. 3. D. R. Stinson: Mật mã Lý thuyết và Thực hành, Nguyễn Bình dịch, Học viện Mật mã, 1995 Dr. Nguyen Nam Hong, Le Quy Don Technical University
REFERENCES (2/2) 4. A. Menezes, P. van Oorschot, S. Vanstone: Handbook of Applied Cryptography, CRC Press, 1996. 5. Electronic Book about Computer Secutity and Cryptography version V4.0, 2005 6. Lawrie Brown: Computer Security Course. And other resources on the Internet. Dr. Nguyen Nam Hong, Le Quy Don Technical University
CHAPTER 1. INTRODUCTION (1/2) 1.1. Background 1.2. Definitions 1.3. Aim of the Course 1.4. Services, Mechanisms, Attacks 1.5. Security Service 1.6. Security Mechanism 1.7. Security Attack Dr. Nguyen Nam Hong, Le Quy Don Technical University
CHAPTER 1. INTRODUCTION (2/2) 1.8. OSI Security Architechture 1.9. Security Services 1.10. Security Services (X.800) 1.11. Security Mechanisms (X.800) 1.12. Classify Security Attacks 1.13. Model for Network Security 1.14. Model for Network Access Security Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.1. Background • Information Security requirements have changed in recent times • traditionally provided by physical and administrative mechanisms • computer use requires automated tools to protect files and other stored information • use of networks and communications links requires measures to protect data during transmission Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.2. Definitions • Computer Security - generic name for the collection of tools designed to protect data and to thwart hackers • Network Security - measures to protect data during their transmission • Internet Security - measures to protect data during their transmission over a collection of interconnected networks Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.3. Aim of Course • our focus is on Internet Security • consists of measures to deter, prevent, detect, and correct security violations that involve the transmission of information Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.4. Services, Mechanisms, Attacks • need systematic way to define requirements • consider three aspects of information security: • security attack • security mechanism • security service • consider in reverse order Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.5. Security Service • is something that enhances the security of the data processing systems and the information transfers of an organization • intended to counter security attacks • make use of one or more security mechanisms to provide the service Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.5. Security Service • replicate functions normally associated with physical documents • eg have signatures, dates; • need protection from disclosure, tampering, or destruction; • be notarized or witnessed; be recorded or licensed Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.6. Security Mechanism • a mechanism that is designed to detect, prevent, or recover from a security attack • no single mechanism that will support all functions required • however one particular element underlies many of the security mechanisms in use: cryptographic techniques • hence our focus on this area Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.7. Security Attack • any action that compromises the security of information owned by an organization • information security is about how to prevent attacks, or failing that, to detect attacks on information-based systems • have a wide range of attacks • can focus of generic types of attacks • note: often threat or attack mean same Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.8. OSI Security Architecture • ITU-T X.800 Security Architecture for OSI • defines a systematic way of defining and providing security requirements • for us it provides a useful, if abstract, overview of concepts we will study Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.9. Security Services • X.800 defines it as: a service provided by a protocol layer of communicating open systems, which ensures adequate security of the systems or of data transfers • RFC 2828 defines it as: a processing or communication service provided by a system to give a specific kind of protection to system resources • X.800 defines it in 5 major categories Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.10. Security Services (X.800) (1/2) • Authentication - assurance that the communicating entity is the one claimed • Access Control - prevention of the unauthorized use of a resource • Data Confidentiality –protection of data from unauthorized disclosure Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.10. Security Services (X.800) (2/2) • Data Integrity - assurance that data received is as sent by an authorized entity • Non-Repudiation - protection against denial by one of the parties in a communication Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.11. Security Mechanisms (X.800) (1/2) • specific security mechanisms: • encipherment, digital signatures, access controls, data integrity, authentication exchange, traffic padding, routing control, notarization Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.11. Security Mechanisms (X.800) (2/2) • pervasive security mechanisms: • trusted functionality, security labels, event detection, security audit trails, security recovery Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.12. Classify Security Attacks (1/2) • passive attacks eavesdropping on, or monitoring of, transmissions to: • obtain message contents, or • monitor traffic flows Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.12. Classify Security Attacks (2/2) • active attacks modification of data stream to: • masquerade of one entity as some other • replay previous messages • modify messages in transit • denial of service Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.13. Model for Network Security (1/3) Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.13. Model for Network Security (2/3) • using this model requires us to (1/2): • design a suitable algorithm for the security transformation • generate the secret information (keys) used by the algorithm Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.13. Model for Network Security (3/3) • using this model requires us to (2/2): • develop methods to distribute and share the secret information • specify a protocol enabling the principals to use the transformation and secret information for a security service Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.14. Model for Network Access Security (1/3) Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.14. Model for Network Access Security (2/3) • using this model requires us to: • select appropriate gatekeeper functions to identify users • implement security controls to ensure only authorised users access designated information or resources Dr. Nguyen Nam Hong, Le Quy Don Technical University
1.14. Model for Network Access Security (3/3) • trusted computer systems can be used to implement this model Dr. Nguyen Nam Hong, Le Quy Don Technical University
Summary • have considered: • computer, network, internet security definitions • security services, mechanisms, attacks • X.800 standard • models for network security • models for network access security Dr. Nguyen Nam Hong, Le Quy Don Technical University