Enhancing Survivability of Security Services using Redundancy

1. Enhancing Survivability of Security Services using Redundancy Presented by: Zijian Cao Joe Ondercin Based on a paper by Matti Hiltunen, Richard D. Schlichting, and Carlos A. Ugarte

2. Overview • Traditional security services • Single method to guarantee security attributes • Single point of vulnerability • Use redundancy to increase survivability • Implement using multiple methods • Implement in ways that can vary unpredictably

3. Requirements • Appropriate techniques • System support

4. Techniques • Use multiple methods to enforce security attribute • If one method remains intact, attribute remains uncompromised • Methods need to be independent • Use of same key by different methods can result in both being defeated

5. Example - Secure Messaging • Encrypt messages with different methods • Use DES, then IDEA • Alternate the sequence of applying DES and IDEA for different messages • Apply different methods to different parts of message • Both methods would have to be identified and broken to compromise data

6. System Support • Simplifies redundancy based survivability techniques using the appropriate software customization framework. • Automation of techniques

7. Example - SecComm • SecComm • A highly configurable secure communicate service • Implemented using Cactus • Cactus • A framework for software customization • Constructs configurable network protocols and services • Implements each service property as a separate software module (called a micro-protocol)

8. Basic Authenticity Privacy Integrity Non-repudiation Attack Specific Replay prevention Known plain text attack prevention Security Properties

9. Basic Security Micro-protocols (MPs) • Individual methods that can be utilized • Addresses security properties • Allows different abstract service properties and their variants to be implemented as independent modules

10. Meta-security MP’s • Applying multiple or alternating basic security micro-protocols • Selected based on the desired properties • Creates a complex protocol • Key feature to enabling redundancy for survivability

11. Examples of Meta-security MP’s • MultiSecurity • Applies multiple basic security MP’s to a message in sequence • AltSecurity • Applies one MP to each message, sequentially from a predetermined list • RandomAltSecurity • Randomly chooses the method for each message

12. Trade-offs • Performance • Configuration constraints

13. Why is this important? • Needs to be considered when designing architecture • Can reduce the potential for compromise • Security through obscurity • Use of available technology

14. Questions