<s>
Remote	B-Protocol
Audio	I-Protocol
Output	I-Protocol
Protocol	I-Protocol
(	O
RAOP	B-Protocol
)	O
is	O
an	O
Internet	O
streaming	O
protocol	O
based	O
on	O
RTSP	B-Protocol
/	O
RTP	B-Protocol
authored	O
by	O
Apple	O
Inc	O
.	O
</s>
<s>
It	O
powers	O
the	O
AirPlay	O
technology	O
built	O
into	O
AirPort	O
Express	O
wireless	O
(	O
802.11b/g/n	O
)	O
access	O
point	O
as	O
well	O
as	O
the	O
Apple	B-Device
TV	I-Device
.	O
</s>
<s>
The	O
major	O
difference	O
from	O
RTSP	B-Protocol
is	O
an	O
initial	O
asymmetric	B-Application
key	I-Application
verification	O
made	O
by	O
iTunes	B-Operating_System
to	O
verify	O
it	O
is	O
communicating	O
with	O
an	O
AirPort	O
Express	O
or	O
an	O
Apple	B-Device
TV	I-Device
(	O
as	O
opposed	O
to	O
a	O
simulation	O
)	O
,	O
and	O
vice	O
versa	O
.	O
</s>
<s>
The	O
data	O
channel	O
is	O
also	O
encrypted	O
by	O
AES	B-Algorithm
,	O
with	O
a	O
random	O
key	O
protected	O
by	O
the	O
asymmetric	B-Application
key	I-Application
mentioned	O
above	O
.	O
</s>
<s>
The	O
RSA	O
public	B-Application
key	I-Application
stored	O
in	O
iTunes	B-Operating_System
was	O
extracted	O
by	O
Jon	O
Lech	O
Johansen	O
,	O
enabling	O
third-party	O
software	O
to	O
stream	O
music	O
to	O
an	O
Airport	O
Express	O
.	O
</s>
<s>
The	O
RSA	O
private	B-Application
key	I-Application
stored	O
in	O
the	O
AirPort	O
Express	O
was	O
extracted	O
by	O
James	O
Laird	O
,	O
enabling	O
simulation	O
of	O
an	O
Airport	O
Express	O
.	O
</s>
