6 The osi model 7-Application 7-Application 6-Presentation 6-Presentation 5-Session 5-Session 4-Transport 4-Transport 3-Network 3-Network 2Data link 2Data Link 1-Physical 1-Physical From Security in Computing, Fifth Edition, by Charles P Pfleeger, et aL. (ISBN: 9780134085043) Copyright 2015 by Pearson Education, Inc. All rights reserved
The OSI Model 6 From Security in Computing, Fifth Edition, by Charles P. Pfleeger, et al. (ISBN: 9780134085043). Copyright 2015 by Pearson Education, Inc. All rights reserved
7 Threats to network communications Interception, or unauthorized viewing Modification, or unauthorized change Fabrication, or unauthorized creation Interruption, or preventing authorized access From Security in Computing, Fifth Edition, by Charles P Pfleeger, et aL. (ISBN: 9780134085043) Copyright 2015 by Pearson Education, Inc. All rights reserved
Threats to Network Communications • Interception, or unauthorized viewing • Modification, or unauthorized change •Fabrication, or unauthorized creation • Interruption, or preventing authorized access 7 From Security in Computing, Fifth Edition, by Charles P. Pfleeger, et al. (ISBN: 9780134085043). Copyright 2015 by Pearson Education, Inc. All rights reserved
8 Security Perimeters Security perimeter 国田 From Security in Computing, Fifth Edition, by Charles P Pfleeger, et aL. (ISBN: 9780134085043) Copyright 2015 by Pearson Education, Inc. All rights reserved
Security Perimeters 8 From Security in Computing, Fifth Edition, by Charles P. Pfleeger, et al. (ISBN: 9780134085043). Copyright 2015 by Pearson Education, Inc. All rights reserved
9 What makes a network vulnerable to interception? Anonymity An attacker can attempt many attacks, anonymously, from thousands of miles away Many points of attack Large networks mean many points of potential entry Sharing Networked systems open up potential access to more users than do single computers System complexity One system is very complex and hard to protect; networks of many different systems, with disparate OSs, vulnerabilities, and purposes are that much more complex Unknown perimeter Networks, especially large ones, change all the time, so it can be hard to tell which systems belong and are behaving, and impossible to tell which systems bridge networks Unknown path There may be many paths, including untrustworthy ones, from one host to another From Security in Computing, Fifth Edition, by Charles P Pfleeger, et aL. (ISBN: 9780134085043) Copyright 2015 by Pearson Education, Inc. All rights reserved
What Makes a Network Vulnerable to Interception? • Anonymity • An attacker can attempt many attacks, anonymously, from thousands of miles away • Many points of attack • Large networks mean many points of potential entry • Sharing • Networked systems open up potential access to more users than do single computers • System complexity • One system is very complex and hard to protect; networks of many different systems, with disparate OSs, vulnerabilities, and purposes are that much more complex • Unknown perimeter • Networks, especially large ones, change all the time, so it can be hard to tell which systems belong and are behaving, and impossible to tell which systems bridge networks • Unknown path • There may be many paths, including untrustworthy ones, from one host to another 9 From Security in Computing, Fifth Edition, by Charles P. Pfleeger, et al. (ISBN: 9780134085043). Copyright 2015 by Pearson Education, Inc. All rights reserved
Unknown Perimeter Network c Network a Network B Network D Network E From Security in Computing, Fifth Edition, by Charles P Pfleeger, et aL. (ISBN: 9780134085043) Copyright 2015 by Pearson Education, Inc. All rights reserved
Unknown Perimeter 10 From Security in Computing, Fifth Edition, by Charles P. Pfleeger, et al. (ISBN: 9780134085043). Copyright 2015 by Pearson Education, Inc. All rights reserved