1 2 Prof. Sead Muftic Matei Ciobanu Morogan Lecture 1: Introduction to Computer s Security Introduction to Computer s Security 4. security services and mechanisms 3 Approach 4 Introduction to Computer s Security 4. security services and mechanisms 1. Based on the textbook 2. Based on Internet standards (RFCs) 3. Mixture of theoretical overview and practical approach (examples) 4. From basic components towards an integrated global network security system 5. Some advanced aspects 5 DES algorithm in Previous Courses DES algorithm in IV2020 6 IV Input file 8 8 8 8 DES DES DES K K K K DES 8 8 8 8 Output file Page 1 1
7 8 Certificate in Previous Courses Certificate in IV2020 Certificate: Serial number Validity period (from, to) Issuer (CA) Subject () Public key Algorithm ID CA signature 30 82 01 F3 30 82 01 9D -- SEQUENCE 02 01 00 -- Serial Number 30 0D -- Signature Algorithm 06 09 2A 86 48 86 F7 0D 01 01 02 05 00 30 64 31 32 -- Issuer s X.500 DN 30 09 06 03 55 04 06 13 02 73 65 30 25 06 03 55 04 0A... 17 0D -- Time Validity 39 34 30 36 32 32 32 31 39 35 30 36 32 32 32 31... 9 Normal flow of messages 10 Introduction to Computer s Security 4. security services and mechanisms Interruption 11 Interception 12 Page 2 2
Modification 13 Fabrication 14 Classification of threats 15 Additional aspects 16 1. Simple client/server model 2. Mainly communication services 3. Static allocation of code Multi party transactions 17 Application requirements 18 1. Simple client/server model 2. Mainly communication services 3. Static allocation 1. of code Multiple senders 2. Multiple recipients 3. Chained transactions 1. Simple client/server model 2. Mainly communication services 3. Static allocation 1. of code Non repudiation 2. e Commerce services 3. Privacy Page 3 3
19 20 Mobile agents security 1. Simple client/server model 2. Mainly communication services 3. Static allocation 1. of code Mobile agents security 2. Applets security 3. Small footprint code Introduction to Computer s Security 4. security services and mechanisms OSI Security Services 21 Additional Services 22 1. Authentication 2. Access control 3. Data confidentiality 4. Data integrity 5. Non - repudiation 1. Availability 2. Authorization 3. Registration (directory) 4. Security management 5. Mobile agents security Security Architecture 23 Not covered 24 1. Key exchange protocols 2. Security platform and APIs 3. Documents encapsulation 4. Integration 5. Smart cards 1. Secure payment transactions 2. Distributed system security 3. Verification and evaluation 4. Java security 5. Generic security objects Page 4 4
25 Simple client/server model 26 Introduction to Computer s Security 4. security services and mechanisms Trusted third party 27 Communication / socket level security 28 Unprotected Protected Unprotected Applications/document level security 29 Smart cards: level security 30 Page 5 5
Additional features 31 Trusted third party 32 1. Non repudiation 2. Storage of secrets 3. mobility 4. Mobile code Functions 33 Security infrastructure 34 TTP TTP TTP TTP A B access security model 35 Firewalls packet filtering 36 Page 6 6
Firewalls application filtering 37 System resources access control 38 39 40 s and application level Reference monitor Application Apache Authorization 41 In closed environments 42 Apache? Security Administration Application Page 7 7
In open networks 43 s security model 44 TCA HCA PCA Certification Infrastructure PCA HCA UCA UCA App client Secure Transactions App server Smart card Crypto modules Certification client Security Platform 45 Questions 46 Introduction to Computer s Security 4. security services and mechanisms? Page 8 8