4.3.3 Security
In normal situations the main focus of security is to protect access to data systems and the information they contain. When dealing with automated systems security issues could lead to major economic losses through damaged equipment, or even loss of life!
Security violations normally come from disgruntled employees, but recently anonymous crackers (incorrectly called hackers in the press) have become a significant threat. Modern operating systems and software are often designed with some security features. Most assume that there is limited physical access to the computer. The most elaborate security system doesn’t work if the the hard drive is stolen. The best strategy to keep a system safe is to understand how hackers can break into a computer. What follows are the most common type of attacks.
Social engineering involves the use of people and trust to get access to a computer. This often involves understanding the psychology of trust and exploiting it to get passwords and other information. A common ruse to get an employee password is as follows. Call an employee in a company likely to have a high level of software access, such as a secretary of a high level executive. Claim to be from the IT (Information Technology) department, talk for a while and then ask for help solving a problem with the password account. When agreement is obtained, ask the secretary to change the account password, and let you know what the new one is.
Crackers will also practice ’surfing’. Shoulder surfing involves peeking over the shoulder of users as they enter passwords. Garbage surfing involves taking a garbage can before being emptied and searching the contents for useful information, such as credit card numbers. Cubicle surfing involves checking for posted passwords around computers. Some users hate to remember passwords and will post them for all to see (or sometimes taped to the bottom of the keyboard). To protect against these types of problems the following strategies help,
• inform users that their passwords are to be given to NOBODY, especially unseen.
- 1.3 PRACTICE PROBLEMS
- 2. AN INTRODUCTION TO LINUX/UNIX
- 2.1 OVERVIEW
- 2.1.1 What is it?
- 2.1.7 Distributions
- 2.1.8 Installing
- 2.2 USING LINUX
- 2.2.1 Some Terminology
- 2.2.4 Processes
- 2.3 NETWORKING
- 2.3.1 Security
- 2.4 INTERMEDIATE CONCEPTS
- 2.4.1 Shells
- 2.4.4 Desktop Tools
- 2.5 LABORATORY - A LINUX SERVER
- 2.8 REFERENCES
- 3.7 ARCHITECTURE OF ‘C’ PROGRAMS (TOP-DOWN)
- 3.9 CASE STUDY - THE BEAMCAD PROGRAM
- 3.9.1 Objectives:
- 3.9.2 Problem Definition:
- 3.9.3 User Interface:
- 3.9.3.1 - Screen Layout (also see figure):
- 3.9.7 Documentation
- 3.9.7.1 - Users Manual:
- 3.9.7.2 - Programmers Manual:
- 3.10 PRACTICE PROBLEMS
- 3.11 LABORATORY - C PROGRAMMING
- 4. NETWORK COMMUNICATION
- 4.1 INTRODUCTION
- 4.2 NETWORKS
- 4.2.1 Topology
- 4.2.3 Networking Hardware
- 4.2.6 SLIP and PPP
- 4.3 INTERNET
- 4.3.2 Computer Ports
- 4.3.3 Security
- 4.4 FORMATS
- 4.4.1 HTML
- 4.4.5 Java
- 4.4.6 Javascript
- 4.6 DESIGN CASES
- 4.9 LABORATORY - NETWORKING
- 5. DATABASES
- 5.2 DATABASE ISSUES
- 6. COMMUNICATIONS
- 6.1 SERIAL COMMUNICATIONS
- 6.2 SERIAL COMMUNICATIONS UNDER LINUX
- 6.3 PARALLEL COMMUNICATIONS
- 7. PROGRAMMABLE LOGIC CONTROLLERS (PLCs)
- 7.12.1 Data Files
- 7.12.1.4 - PLC Status Bits (for PLC-5s)
- 7.12.1.5 - User Function Memory
- 7.13 INSTRUCTION TYPES
- 7.13.1 Program Control Structures
- 7.13.2 Branching and Looping
- 7.13.3 Basic Data Handling
- 7.13.3.1 - Move Functions
- 7.15 LOGICAL FUNCTIONS
- 7.20 DESIGN TECHNIQUES
- 7.20.1 State Diagrams
- 7.23.1 SWITCHED INPUTS AND OUTPUTS
- 7.25 PRACTICE PROBLEMS
- 8.2 PROPRIETARY NETWORKS
- 8.2.0.1 - Data Highway
- 8.4 LABORATORY - DEVICENET
- 8.5 TUTORIAL - SOFTPLC AND DEVICENET
- 9. INDUSTRIAL ROBOTICS
- 9.1 INTRODUCTION
- 9.1.1 Basic Terms
- 9.2.2 Types of Robots
- 9.2.2.1 - Robotic Arms
- 9.3 MECHANISMS
- 9.5.2 Movemaster Programs
- 9.5.2.0.1 - Language Examples
- 9.5.3 Command Summary
- 9.6 PRACTICE PROBLEMS
- 9.7 LABORATORY - MITSUBISHI RV-M1 ROBOT
- 10. OTHER INDUSTRIAL ROBOTS
- 10.1 SEIKO RT 3000 MANIPULATOR
- 10.1.1.2 - Commands Summary
- 10.2 IBM 7535 MANIPULATOR
- 10.2.1 AML Programs
- 10.3 ASEA IRB-1000
- 10.6 LABORATORY - SEIKO RT-3000 ROBOT
- 11. ROBOT APPLICATIONS
- 11.0.1 Overview
- 11.1 END OF ARM TOOLING (EOAT)
- 11.1.1 EOAT Design
- 11.1.2 Gripper Mechanisms
- 11.1.3 Magnetic Grippers
- 11.1.3.1 - Adhesive Grippers
- 11.1.4 Expanding Grippers
- 11.3 INTERFACING
- 12. SPATIAL KINEMATICS
- 12.1 BASICS
- 12.2.1 Denavit-Hartenberg Transformation (D-H)
- 12.3 SPATIAL DYNAMICS
- 12.3.1 Moments of Inertia About Arbitrary Axes
- 12.4 DYNAMICS FOR KINEMATICS CHAINS
- 12.4.1 Euler-Lagrange
- 12.4.2 Newton-Euler
- 13.1.3 Modeling the Robot
- 13.2.2 Computer Control of Robot Paths (Incremental Interpolation)
- 13.4 LABORATORY - AXIS AND MOTION CONTROL
- 14. CNC MACHINES
- 14.1 MACHINE AXES
- 14.2 NUMERICAL CONTROL (NC)
- 14.3 EXAMPLES OF EQUIPMENT
- 14.3.1 EMCO PC Turn 50
- 14.4 PRACTICE PROBLEMS
- 14.5 TUTORIAL - EMCO MAIER PCTURN 50 LATHE (OLD)
- 14.6.1 LABORATORY - CNC MACHINING
- 15.3 PROPRIETARY NC CODES
- 16.5 DISCRETE IO
- 16.6 COUNTERS AND TIMERS
- 16.7 ACCESSING DAQ CARDS FROM LINUX
- 16.8 SUMMARY
- 16.9 PRACTICE PROBLEMS
- 17. VISIONS SYSTEMS
- 17.1 OVERVIEW
- 17.11 PRACTICE PROBLEMS
- 18. INTEGRATION ISSUES
- 18.1 CORPORATE STRUCTURES
- 18.2 CORPORATE COMMUNICATIONS
- 19. MATERIAL HANDLING
- 19.1 INTRODUCTION
- 19.3 PRACTICE QUESTIONS
- 19.4 LABORATORY - MATERIAL HANDLING SYSTEM
- 19.4.1 System Assembly and Simple Controls
- 19.5 AN EXAMPLE OF AN FMS CELL
- 19.5.1 Overview
- 19.6 THE NEED FOR CONCURRENT PROCESSING
- 20. PETRI NETS
- 20.1 INTRODUCTION
- 20.2 A BRIEF OUTLINE OF PETRI NET THEORY
- 20.4.3 An Exclusive OR Transition:
- 20.4.5 RELATIONAL NETS
- 20.7 PRACTICE PROBLEMS
- 21. PRODUCTION PLANNING AND CONTROL
- 21.1 OVERVIEW
- 21.2 SCHEDULING
- 21.3 SHOP FLOOR CONTROL
- 21.3.1 Shop Floor Scheduling - Priority Scheduling
- 22. SIMULATION
- 22.3 DESIGN OF EXPERIMENTS
- 23. PLANNING AND ANALYSIS
- 23.1 FACTORS TO CONSIDER
- 24. REFERENCES
- 25. APPENDIX A - PROJECTS
- 25.1 TOPIC SELECTION
- 25.1.1 Previous Project Topics
- 25.2 CURRENT PROJECT DESCRIPTIONS