MPI-I-92-104
Circuits and multi-party protocols
Grolmusz, Vince
January 1992, 16 pages.
.
Status: available - back from printing
We present a multi--party protocol for computing certain functions of
an $n\times k$ $0-1$ matrix $A$. The protocol is for $k$ players, where
player $i$ knows every column of $A$, except column $i$. {\it Babai,
Nisan}
and {\it Szegedy} proved that to compute $GIP(A)$ needs $\Omega (n/4^k)$
bits to communicate. We show that players can count those rows of matrix $A$
which sum is divisible by $m$, with communicating only $O(mk\log n)$ bits,
while counting the rows with sum congruent to 1 $\pmod m$ needs
$\Omega (n/4^k)$ bits of communication (with an odd $m$ and $k\equiv m\pmod
{2m}$). $\Omega(n/4^k)$ communication is needed also to count the rows
of $A$ with sum in any congruence class
modulo an {\it even} $m$.
The exponential gap in communication complexities allows us to prove
exponential lower bounds for the sizes of some bounded--depth circuits with
MAJORITY, SYMMETRIC and MOD$_m$ gates, where $m$ is an odd
-- prime or composite -- number.
URL to this document: https://domino.mpi-inf.mpg.de/internet/reports.nsf/NumberView/1992-104
BibTeX
@TECHREPORT{Grolmusz92a,
AUTHOR = {Grolmusz, Vince},
TITLE = {Circuits and multi-party protocols},
TYPE = {Research Report},
INSTITUTION = {Max-Planck-Institut f{\"u}r Informatik},
ADDRESS = {Im Stadtwald, D-66123 Saarbr{\"u}cken, Germany},
NUMBER = {MPI-I-92-104},
MONTH = {January},
YEAR = {1992},
ISSN = {0946-011X},
}