1. KERBEROS

2. CONTENTS
Introduction
What is Kerberos?
Where does the name Kerberos came from?
Why Kerberos?
What does Kerberos do?
Kerberos software components
How Kerberos works?
Kerberos names
Kerberos database
Kerberos from the outside looking in
Kerberos issue and open problems
Effectiveness of Kerberos
Kerberos status
How widespread is deployment?
Advantages and Disadvantages
Commercial support for Kerberos
MIT Kerberos team
Conclusion
References

3. INTRODUCTION WHAT IS KERBEROS?
A NETWORK AUTHENTICATION PROTOCOL
WHAT IS KERBEROS?
KERBEROS IS A TRUSTED THIRD-PARTY
AUTHENTICATION SERVICE BASED ON THE MODEL
PRESENTED BY NEEDHAM AND_SCHROEDER.

4. Where does the name “Kerberos” came from?
The name Kerberos comes from Greek mythology; it is the three-headed dog that guarded the entrance to Hades.
“CERBERUS” is the Latin spelling of the Greek “Kerberos”, and according to the OED is pronounced like “Serberus”, but that is quite at odds with the Greek, as the initial consonant is a “k”.MIT project Athena chose to use the Greek spelling and pronunciation.

5. WHY KERBEROS? SECURE THE DATA RELIABLE SERVICE TRANSPERANCY
SCALABILITY

6. WHAT DOES KERBEROS DO?
Kerberos keeps a database of its clients and their private keys.
Kerberos provides three distinct levels of protection.
Kerberos provides safe messages.

7. KERBEROS SOFTWARE COMPONENTS
KERBEROS APPLICATION LIBRARY
ENCRYPTION LIBRARY
DATABASE LIBRARY
DATABASE ADMINISTRATION PROGRAMS
ADMINISTRATION SERVER
AUTHENTICATION SERVER
DB PROPOGATION SOFTWARE
USER PROGRAMS

8. Requesting a Kerberos Service
Getting the Initial Kerberos Ticket
Getting Kerberos Server Tickets
HOW KERBEROS WORKS

9. Flow of Authentication Information
Logging on to the workstation
P W
A O
S R
S D
ENTRY 3
1 User name
TGT,TGS 2
Authentication
Server
Workstation

10. 4 TGT 5 Session key requested S E I O N key TICKET User name
NT address
Service name
Time stamp
Session key 4
TGS Session key
TGT
Ticket, 2 copies
of session key
Workstation 5
Ticket Granting
Server
Application
Server

11. 8 Workstation Application Server Verifying the request 6 Ticket
Session Key 6
Ticket
7 Random number
Random Number 8
Workstation
Application
Server
Session Key

13. KERBEROS NAMES Key referral between Domains
Key referral between Trusted Domains

16. KERBEROS DATABASE The KDBM Server The kadmin and kpasswd Programs
Kerberos Database Replication

17. Kerberos from the Outside Looking In Kerberos User's Eye View
Kerberos From the Programmer's Viewpoint
The Kerberos Administrator's Job

18. Kerberos Issues and open Problems
How to decide the correct lifetime for a ticket?
How to allow proxies?
How to guarantee workstation integrity?

19. HOW EFFECTIVE IS KERBEROS?

20. KERBEROS STATUS
A prototype version of Kerberos went into production in September of Since January of 1987, Kerberos has been Project Athena's sole means of authenticating its 5,000 users, 650 workstations, and 65 servers. In addition, Kerberos is now being used in place of .rhosts files for controlling access in several of Athena's timesharing systems.

21. HOW WIDESPREAD IS DEPLOYMENT?

22. ADVANTAGES AND DISADVANTAGES

23. COMMERCIAL SUPPORT FOR KERBEROS
CyberSafe Corporation
InterSoft International, Inc.

24. THE MIT KERBEROS TEAM Jeff Schiller ('79) Ted Ts'o ('90) Tom Yu ('96)
MIT Team Members
Jeff Schiller ('79)
Ted Ts'o ('90)
Tom Yu ('96)
Ken Raeburn ('88)
Paul Hill
Marshall Vale
Miroslav Jurisic
Alexis Ellwood
Danilo Almeida

25. CONCLUSION

26. REFERENCES www.krbcore@mit.edu http://web.mit.edu/kerberos
The Kerberos newsgroup
Kerberos on the Macintosh
comp.protocols.kerberosFAQ

28. THANK 'U'