<s>
Wireless	B-Protocol
Transport	I-Protocol
Layer	I-Protocol
Security	I-Protocol
(	O
WTLS	O
)	O
is	O
a	O
security	O
protocol	O
,	O
part	O
of	O
the	O
Wireless	B-Protocol
Application	I-Protocol
Protocol	I-Protocol
(	O
WAP	O
)	O
stack	O
.	O
</s>
<s>
It	O
sits	O
between	O
the	O
WTP	B-Protocol
and	O
WDP	B-Protocol
layers	O
in	O
the	O
WAP	B-Protocol
communications	I-Protocol
stack	I-Protocol
.	O
</s>
<s>
WTLS	O
is	O
derived	O
from	O
TLS	B-Protocol
.	O
</s>
<s>
Packet	O
based	O
design	O
—	O
TLS	B-Protocol
is	O
designed	O
for	O
use	O
over	O
a	O
data	O
stream	O
.	O
</s>
<s>
WTLS	O
has	O
been	O
superseded	O
in	O
the	O
WAP	O
Wireless	B-Protocol
Application	I-Protocol
Protocol	I-Protocol
2.0	O
standard	O
by	O
the	O
End-to-end	O
Transport	B-Protocol
Layer	I-Protocol
Security	I-Protocol
Specification	O
.	O
</s>
<s>
WTLS	O
uses	O
cryptographic	O
algorithms	O
and	O
in	O
common	O
with	O
TLS	B-Protocol
allows	O
negotiation	O
of	O
cryptographic	O
suites	O
between	O
client	O
and	O
server	O
.	O
</s>
<s>
Encryption/Decryption	O
at	O
the	O
gateway	O
—	O
in	O
the	O
WAP	O
architecture	O
the	O
content	O
is	O
typically	O
stored	O
on	O
the	O
server	O
as	O
uncompressed	O
WML	B-General_Concept
(	O
an	O
XML	B-Protocol
DTD	O
)	O
.	O
</s>
<s>
That	O
content	O
is	O
retrieved	O
by	O
the	O
gateway	O
using	O
HTTP	B-Protocol
and	O
compressed	O
into	O
WBXML	B-Protocol
,	O
in	O
order	O
to	O
perform	O
that	O
compression	O
the	O
gateway	O
must	O
be	O
able	O
to	O
handle	O
the	O
WML	B-General_Concept
in	O
cleartext	O
,	O
so	O
even	O
if	O
there	O
is	O
encryption	O
between	O
the	O
client	O
and	O
the	O
gateway	O
(	O
using	O
WTLS	O
)	O
and	O
between	O
the	O
gateway	O
and	O
the	O
originating	O
server	O
(	O
using	O
HTTPS	B-Protocol
)	O
the	O
gateway	O
acts	O
as	O
a	O
man-in-the-middle	O
.	O
</s>
<s>
Digest	O
truncation	O
—	O
HMAC	B-Algorithm
message	O
digests	O
are	O
truncated	O
to	O
reduce	O
transmission	O
overhead	O
,	O
this	O
reduces	O
the	O
theoretical	O
effectiveness	O
of	O
the	O
HMAC	B-Algorithm
potentially	O
reducing	O
the	O
data	O
integrity	O
protection	O
.	O
</s>
<s>
Inadequate	O
review	O
—	O
WTLS	O
is	O
significantly	O
different	O
from	O
TLS	B-Protocol
,	O
it	O
is	O
not	O
clear	O
that	O
the	O
changes	O
made	O
to	O
WTLS	O
have	O
not	O
in	O
some	O
way	O
weakened	O
the	O
security	O
.	O
</s>
