<s>
Private	B-Protocol
Communications	I-Protocol
Technology	I-Protocol
(	O
PCT	O
)	O
1.0	O
was	O
a	O
protocol	O
developed	O
by	O
Microsoft	O
in	O
the	O
mid-1990s	O
.	O
</s>
<s>
PCT	O
was	O
designed	O
to	O
address	O
security	O
flaws	O
in	O
version	O
2.0	O
of	O
Netscape	O
's	O
Secure	B-Protocol
Sockets	I-Protocol
Layer	I-Protocol
protocol	O
and	O
to	O
force	O
Netscape	O
to	O
hand	O
control	O
of	O
the	O
then-proprietary	O
SSL	O
protocol	O
to	O
an	O
open	O
standards	O
body	O
.	O
</s>
<s>
PCT	O
has	O
since	O
been	O
superseded	O
by	O
SSLv3	O
and	O
Transport	B-Protocol
Layer	I-Protocol
Security	I-Protocol
.	O
</s>
<s>
For	O
a	O
while	O
it	O
was	O
still	O
supported	O
by	O
Internet	O
Explorer	O
,	O
but	O
PCT	O
1.0	O
has	O
been	O
disabled	O
by	O
default	O
since	O
IE	B-Protocol
5	I-Protocol
and	O
the	O
option	O
was	O
removed	O
in	O
IE6	O
.	O
</s>
<s>
It	O
is	O
still	O
found	O
in	O
IIS	B-Application
and	O
in	O
the	O
Windows	O
operating	O
system	O
libraries	O
,	O
although	O
in	O
Windows	B-Application
Server	I-Application
2003	I-Application
it	O
is	O
disabled	O
by	O
default	O
.	O
</s>
<s>
It	O
is	O
used	O
by	O
old	O
versions	O
of	O
MSMQ	B-Application
as	O
the	O
only	O
choice	O
.	O
</s>
