A Tight Lower Bound for k-Set Agreement

: Weprove tight bounds on the time needed to solve k-set agreement, a natural generalization of consensus. We analyze this problem in a synchronous, message-passing model where processors fail by crashing. We prove a lower bound of bf=kc+1 rounds of communication for solutions to k-set agreement that tolerate f failures. This bound is tight, and shows that there is an inherent tradeo between the running time, the degree of coordination required, and the number of faults tolerated, even in idealized models like the synchronous model. The proof of this result is interesting because it is a geometric combination of other well-known proof techniques.

• Type: Conference
• Year: 1993
• Where: FOCS
• Authors: Soma Chaudhuri, Maurice Herlihy, Nancy A. Lynch, Mark R. Tuttle
• Keywords: FOCS 1993, K-set Agreement, Theoretical Computer Science, Tight Bounds, Well-known Proof Techniques