<s>
Key	B-General_Concept
distribution	I-General_Concept
is	O
an	O
important	O
issue	O
in	O
wireless	B-Architecture
sensor	I-Architecture
network	I-Architecture
(	O
WSN	B-Architecture
)	O
design	O
.	O
</s>
<s>
WSNs	B-Architecture
are	O
networks	O
of	O
small	O
,	O
battery-powered	O
,	O
memory-constraint	O
devices	O
named	O
sensor	B-Device
nodes	I-Device
,	O
which	O
have	O
the	O
capability	O
of	O
wireless	O
communication	O
over	O
a	O
restricted	O
area	O
.	O
</s>
<s>
Key	O
predistribution	O
schemes	O
are	O
various	O
methods	O
that	O
have	O
been	O
developed	O
by	O
academicians	O
for	O
a	O
better	O
maintenance	O
of	O
PEA	O
management	O
in	O
WSNs	B-Architecture
.	O
</s>
<s>
During	O
these	O
phases	O
,	O
secret	O
keys	O
are	O
generated	O
,	O
placed	O
in	O
sensor	B-Device
nodes	I-Device
,	O
and	O
each	O
sensor	B-Device
node	I-Device
searches	O
the	O
area	O
in	O
its	O
communication	O
range	O
to	O
find	O
another	O
node	O
to	O
communicate	O
.	O
</s>
<s>
There	O
are	O
a	O
number	O
of	O
aspects	O
of	O
WSNs	B-Architecture
on	O
which	O
key	O
predistribution	O
schemes	O
are	O
competing	O
to	O
achieve	O
a	O
better	O
result	O
.	O
</s>
<s>
Local	O
connectivity	O
means	O
the	O
probability	O
that	O
any	O
two	O
sensor	B-Device
nodes	I-Device
have	O
a	O
common	O
key	O
with	O
which	O
they	O
can	O
establish	O
a	O
secure	O
link	O
to	O
communicate	O
.	O
</s>
<s>
Apart	O
from	O
these	O
,	O
two	O
other	O
critical	O
issues	O
in	O
WSN	B-Architecture
design	O
are	O
computational	O
cost	O
and	O
hardware	O
cost	O
.	O
</s>
