Abstract
It was recently shown by Michael Rabin that a sequence of random 0-1 values, prepared and distributed by a trusted "dealer,"can be used to achieve Byzantine agreement in constant expected time in a network of processors. A natural question is whether it is possible to generate these values uniformly at random within the network. In this paper we present a cryptography based protocol for agreement on a 0-1 random value, if less than half of the processors are faulty. In fact the protocol allows uniform sampling from any finite set, and thus solves the problem of choosing a network leader uniformly at random. The protocol is usable both when all the communication is via "broadcast,"in which case it needs three rounds of information exchange, and when each pair of processors communicate on a private line, in which case it, needs 3t + 3 rounds, where t is the number of faulty processors. The protocol remains valid even if passive eavesdropping is allowed. On the other hand we show that no (probabilistic) protocol can achieve agreement on a fair coin in fewer phases then necessary for Byzantine agreement, and hence the "pre-dealt"nature of the random sequence required for Rabin's algorithm is crucial.
Original language | English |
---|---|
Title of host publication | 25th Annual Symposium on Foundations of Computer Science, FOCS 1984 |
Publisher | IEEE Computer Society |
Pages | 157-170 |
Number of pages | 14 |
ISBN (Electronic) | 081860591X |
State | Published - 1984 |
Event | 25th Annual Symposium on Foundations of Computer Science, FOCS 1984 - Singer Island, United States Duration: 24 Oct 1984 → 26 Oct 1984 |
Publication series
Name | Proceedings - Annual IEEE Symposium on Foundations of Computer Science, FOCS |
---|---|
Volume | 1984-October |
ISSN (Print) | 0272-5428 |
Conference
Conference | 25th Annual Symposium on Foundations of Computer Science, FOCS 1984 |
---|---|
Country/Territory | United States |
City | Singer Island |
Period | 24/10/84 → 26/10/84 |
Bibliographical note
Publisher Copyright:© 1984 IEEE.