<s>
The	O
Open	O
eXchange	O
Data	O
Format	O
,	O
or	O
OpenXDF	B-Algorithm
,	O
is	O
an	O
open	O
,	O
XML-based	O
standard	O
for	O
the	O
digital	O
storage	O
and	O
exchange	O
of	O
time-series	O
physiological	O
signals	O
and	O
metadata	O
.	O
</s>
<s>
OpenXDF	B-Algorithm
primarily	O
focuses	O
on	O
electroencephalography	B-Application
and	O
polysomnography	O
.	O
</s>
<s>
Neurotronics	O
began	O
work	O
on	O
OpenXDF	B-Algorithm
in	O
2003	O
with	O
the	O
goal	O
of	O
providing	O
a	O
modern	O
,	O
open	O
,	O
and	O
extensible	O
file	O
format	O
with	O
which	O
clinicians	O
and	O
researchers	O
can	O
share	O
physiological	O
data	O
and	O
metadata	O
,	O
such	O
as	O
signal	O
data	O
,	O
signal	O
montages	O
,	O
patient	O
demographics	O
,	O
and	O
event	O
logs	O
.	O
</s>
<s>
Neurotronics	O
released	O
the	O
first	O
draft	O
of	O
the	O
OpenXDF	B-Algorithm
Specification	O
just	O
before	O
the	O
18th	O
meeting	O
of	O
the	O
Associated	O
Professional	O
Sleep	O
Societies	O
in	O
2004	O
.	O
</s>
<s>
Neurotronics	O
has	O
since	O
relinquished	O
control	O
of	O
the	O
format	O
to	O
the	O
OpenXDF	B-Algorithm
Consortium	O
.	O
</s>
<s>
As	O
of	O
version	O
1.0	O
,	O
OpenXDF	B-Algorithm
is	O
100%	O
backward	O
compatible	O
with	O
the	O
European	B-Algorithm
Data	I-Algorithm
Format	I-Algorithm
(	O
EDF	O
)	O
,	O
the	O
current	O
de	O
facto	O
standard	O
format	O
for	O
physiological	O
data	O
exchange	O
.	O
</s>
<s>
OpenXDF	B-Algorithm
is	O
a	O
tiered	O
framework	O
designed	O
to	O
allow	O
standardized	O
and	O
custom	O
specializations	O
of	O
the	O
format	O
while	O
enforcing	O
a	O
common	O
foundation	O
that	O
provides	O
a	O
high-level	O
of	O
compatibility	O
between	O
unrelated	O
systems	O
.	O
</s>
<s>
OpenXDF	B-Algorithm
expands	O
on	O
EDF	O
by	O
providing	O
standardized	O
support	O
for	O
extensive	O
patient	O
information	O
,	O
display	O
montages	O
,	O
annotations	O
,	O
and	O
scoring	O
information	O
.	O
</s>
<s>
OpenXDF	B-Algorithm
requires	O
the	O
use	O
of	O
a	O
XML	B-Protocol
1.0	O
compliant	O
parser	O
that	O
supports	O
UTF-8	O
and	O
UTF-16	O
.	O
</s>
<s>
OpenXDF	B-Algorithm
supports	O
fully	O
and	O
independently	O
configurable	O
data	O
signals	O
.	O
</s>
<s>
OpenXDF	B-Algorithm
supports	O
encryption	O
of	O
the	O
XML	B-Protocol
file	O
using	O
TwoFish	B-Algorithm
in	O
Cipher	O
Feedback	O
(	O
CFB	O
)	O
mode	O
with	O
a	O
256-bit	O
key	O
created	O
from	O
a	O
UTF-8	O
encoded	O
password	O
hashed	O
with	O
SHA-256	B-Algorithm
.	O
</s>
<s>
In	O
addition	O
,	O
OpenXDF	B-Algorithm
supports	O
integrity	O
verification	O
using	O
a	O
SHA-512	B-Algorithm
hash	O
of	O
the	O
original	O
XML	B-Protocol
file	O
.	O
</s>
