<s>
In	O
cryptography	O
,	O
rekeying	B-General_Concept
refers	O
to	O
the	O
process	O
of	O
changing	O
the	O
session	O
key	O
—	O
the	O
encryption	O
key	O
of	O
an	O
ongoing	O
communication	O
—	O
in	O
order	O
to	O
limit	O
the	O
amount	O
of	O
data	O
encrypted	O
with	O
the	O
same	O
key	O
.	O
</s>
<s>
In	O
contemporary	O
systems	O
,	O
rekeying	B-General_Concept
is	O
implemented	O
by	O
forcing	O
a	O
new	O
key	O
exchange	O
,	O
typically	O
through	O
a	O
separate	O
protocol	O
like	O
Internet	B-Protocol
key	I-Protocol
exchange	I-Protocol
(	O
IKE	O
)	O
.	O
</s>
<s>
A	O
prominent	O
application	O
is	O
Wi-Fi	O
Protected	O
Access	O
(	O
WPA	O
)	O
,	O
the	O
extended	O
security	O
protocol	O
for	O
wireless	O
networks	O
that	O
addresses	O
the	O
shortcomings	O
of	O
its	O
predecessor	O
,	O
WEP	B-Protocol
,	O
by	O
frequently	O
replacing	O
session	O
keys	O
through	O
the	O
Temporal	B-Protocol
Key	I-Protocol
Integrity	I-Protocol
Protocol	I-Protocol
(	O
TKIP	O
)	O
,	O
thus	O
defeating	O
some	O
well-known	O
key	O
recovery	O
attacks	O
.	O
</s>
<s>
In	O
public	B-Architecture
key	I-Architecture
infrastructure	I-Architecture
,	O
rekeying	B-General_Concept
(	O
or	O
"	O
re-keying	O
"	O
)	O
leads	O
to	O
issuance	O
of	O
new	O
certificate	O
(	O
in	O
contrast	O
to	O
certificate	O
renewal	O
-	O
issuance	O
of	O
new	O
certificate	O
for	O
the	O
same	O
key	O
,	O
which	O
is	O
usually	O
not	O
allowed	O
by	O
CAs	O
)	O
.	O
</s>
