Upcoming SlideShare
×

# Byzantine General Problem - Siddharth Chaudhry

1,382 views
1,100 views

Published on

Byzantine General Problem Reliable computer system must be able to deal with failure of one or more of its components. Whenever a failed component exhibits a type of behavior it is generally referred as Byzantine General Problem. This type of behavior is often overlooked and involves mainly sending conflicting information to different parts of system.

Published in: Education
0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total views
1,382
On SlideShare
0
From Embeds
0
Number of Embeds
16
Actions
Shares
0
16
0
Likes
0
Embeds 0
No embeds

No notes for slide

### Byzantine General Problem - Siddharth Chaudhry

1. 1. Course Name: Computer Networking – Class of 2006Professor: Dr. Gertrude LevineName: Chaudhry SiddharthEmail: siddchaudhry@fdu.eduSub: Regarding the Byzantine General Problem--------------------------------------------------------------------------------- Reliable computer system must be able to deal with failure of one ormore of its components. Whenever a failed component exhibits atype of behavior it is generally referred as Byzantine GeneralProblem. This type of behavior is often overlooked and involvesmainly sending conflicting information to different parts of system.This research was supported in part by NASA and the ArmyResearch office and Ballistic Missile Defense.Basic Goals of BGP 1) All loyal generals decide on same plan of action 2) A small number of traitors cannot cause a bad plan to be adopted.To satisfy condition first all general use the same method of combinginformation to come up with a plan.Consider the formal definition with an army exampleAssume that we have one commanding general and his subordinategeneralsConditions to be assumed All loyal subordinate generals obey the same order. If the commanding general is loyal then every subordinate generalfollows the order.
2. 2. Problem1) Oral message can be easily changed.2) No Solution works unless more than 2/3rd of general are loyal3) Even with 3 generals one traitor makes the protocol fail.Understanding the Problem through Figures.
3. 3. Solution for Oral Messages
4. 4. We have assume the following conditions for Oral Messaging:1) Every message which is sent is delivered correctly. We assume that traitor is not capable to interfere communicationbetween two generals2) Receiver has knowledge of who have sent the message.Traitors are not capable to confuse the message by sending extramessage3) Absence can be detected Default message is “Retreat”The ALGORITHM for Oral message is as follows:
5. 5. What if we are not fully connected?What are Practical Implications of this algorithm?
6. 6. The Conclusion is as Follows Reference:“http://homes.cerias.purdue.edu/~crisn/courses/cs590T/cs590T_lect4_byzantine_generals.pdf”