Dealer's random bits in perfect secret sharing schemes
Dealer's random bits in perfect secret sharing schemes
L. Csirmaz:
A triangle inequality for polymatroids
A matroid is a submodular and monotome function f
from a lattice L to the non-negative real numbers.
The conditional rank, coming from entrophy theory,
is defined as
f(x|y)=f(xy)-f(y).
Finally, we can define the distance of two lattice
elements by
f(x|y)+f(y|x)
d(x,y) = -------------.
f(xy)
We show that this satisfies the triangle inequality in all
polymatroids.