<s>
FreeOTFE	B-Application
is	O
a	O
discontinued	O
open	B-Application
source	I-Application
computer	O
program	O
for	O
on-the-fly	O
disk	O
encryption	O
(	O
OTFE	O
)	O
.	O
</s>
<s>
On	O
Microsoft	B-Application
Windows	I-Application
,	O
and	O
Windows	B-Operating_System
Mobile	I-Operating_System
(	O
using	O
FreeOTFE4PDA	B-Application
)	O
,	O
it	O
can	O
create	O
a	O
virtual	B-Application
drive	I-Application
within	O
a	O
file	O
or	O
partition	B-Application
,	O
to	O
which	O
anything	O
written	O
is	O
automatically	O
encrypted	O
before	O
being	O
stored	O
on	O
a	O
computer	O
's	O
hard	B-Device
or	O
USB	O
drive	O
.	O
</s>
<s>
It	O
is	O
similar	O
in	O
function	O
to	O
other	O
disk	O
encryption	O
programs	O
including	O
TrueCrypt	B-Application
and	O
Microsoft	O
's	O
BitLocker	O
.	O
</s>
<s>
The	O
FreeOTFE	B-Application
website	O
is	O
unreachable	O
as	O
of	O
June	O
2013	O
and	O
the	O
domain	O
name	O
is	O
now	O
registered	O
by	O
a	O
domain	O
squatter	O
.	O
</s>
<s>
In	O
June	O
2014	O
,	O
a	O
fork	B-Application
of	O
the	O
project	O
now	O
named	O
LibreCrypt	B-Application
appeared	O
on	O
GitHub	B-Application
.	O
</s>
<s>
FreeOTFE	B-Application
was	O
initially	O
released	O
by	O
Sarah	O
Dean	O
in	O
2004	O
,	O
and	O
was	O
the	O
first	O
open	B-Application
source	I-Application
code	I-Application
disk	O
encryption	O
system	O
that	O
provided	O
a	O
modular	O
architecture	O
allowing	O
3rd	O
parties	O
to	O
implement	O
additional	O
algorithms	O
if	O
needed	O
.	O
</s>
<s>
Older	O
FreeOTFE	B-Application
licensing	O
required	O
that	O
any	O
modification	O
to	O
the	O
program	O
be	O
placed	O
in	O
the	O
public	O
domain	O
.	O
</s>
<s>
This	O
does	O
not	O
conform	O
technically	O
to	O
section	O
3	O
of	O
the	B-License
Open	I-License
Source	I-License
definition	I-License
.	O
</s>
<s>
The	O
FreeOTFE	B-Application
license	O
has	O
not	O
been	O
approved	O
by	O
the	O
and	O
is	O
not	O
certified	O
to	O
be	O
labeled	O
with	O
the	O
open-source	B-Application
certification	O
mark	O
.	O
</s>
<s>
LUKS	O
,	O
cryptoloop	B-Application
,	O
dm-crypt	O
)	O
,	O
allowing	O
data	O
encrypted	O
under	O
Linux	O
to	O
be	O
read	O
(	O
and	O
written	O
)	O
freely	O
.	O
</s>
<s>
It	O
was	O
the	O
first	O
open	B-Application
source	I-Application
transparent	O
disk	O
encryption	O
system	O
to	O
support	O
Windows	B-Application
Vista	I-Application
and	O
PDAs	O
.	O
</s>
<s>
FreeOTFE	B-Application
also	O
allows	O
any	O
number	O
of	O
"	O
hidden	O
volumes	O
"	O
to	O
be	O
created	O
,	O
giving	O
plausible	O
deniability	O
and	O
deniable	O
encryption	O
,	O
and	O
also	O
has	O
the	O
option	O
of	O
encrypting	O
full	O
partitions	B-Application
or	O
disks	O
(	O
but	O
not	O
the	O
system	O
partition	B-Application
)	O
.	O
</s>
<s>
FreeOTFE	B-Application
can	O
be	O
used	O
in	O
"	O
portable	O
"	O
(	O
or	O
"	O
traveller	O
"	O
)	O
mode	O
,	O
which	O
allows	O
it	O
to	O
be	O
kept	O
on	O
a	O
USB	O
drive	O
or	O
other	O
portable	O
media	O
,	O
together	O
with	O
its	O
encrypted	O
data	O
,	O
and	O
carried	O
around	O
.	O
</s>
<s>
This	O
allows	O
it	O
to	O
be	O
used	O
under	O
Microsoft	B-Application
Windows	I-Application
without	O
installation	O
of	O
the	O
complete	O
program	O
to	O
"	O
mount	O
"	O
and	O
access	O
the	O
encrypted	O
data	O
through	O
a	O
virtual	O
disk	O
.	O
</s>
<s>
The	O
use	O
of	O
this	O
mode	O
requires	O
installing	O
device	B-Application
drivers	I-Application
(	O
at	O
least	O
temporarily	O
)	O
to	O
create	O
virtual	O
disks	O
,	O
and	O
as	O
a	O
consequence	O
administrator	O
rights	O
are	O
needed	O
to	O
start	O
this	O
traveller	O
mode	O
.	O
</s>
<s>
As	O
with	O
most	O
open	B-Application
source	I-Application
software	I-Application
that	O
uses	O
device	B-Application
drivers	I-Application
,	O
the	O
user	O
must	O
enable	O
test	O
signing	O
when	O
running	O
Windows	B-Application
Vista	I-Application
x64	O
and	O
Windows	O
7	O
x64	O
systems	O
.	O
</s>
<s>
Packaged	O
with	O
FreeOTFE	B-Application
is	O
another	O
program	O
called	O
"	O
FreeOTFE	B-Application
Explorer	I-Application
"	O
,	O
which	O
provides	O
a	O
driverless	O
system	O
that	O
allows	O
encrypted	O
disks	O
to	O
be	O
used	O
without	O
administrator	O
rights	O
.	O
</s>
<s>
This	O
allows	O
FreeOTFE	B-Application
encrypted	O
data	O
to	O
be	O
used	O
on	O
(	O
for	O
example	O
)	O
public	O
computers	O
found	O
in	O
libraries	O
or	O
computer	O
kiosks	O
(	O
interactive	O
kiosks	O
)	O
,	O
where	O
administrator	O
rights	O
are	O
unavailable	O
.	O
</s>
<s>
Unlike	O
FreeOTFE	B-Application
,	O
FreeOTFE	B-Application
Explorer	I-Application
does	O
not	O
provide	O
on-the-fly	O
encryption	O
through	O
a	O
virtual	B-Application
drive	I-Application
.	O
</s>
<s>
Instead	O
it	O
lets	O
files	O
be	O
stored	O
and	O
extracted	O
from	O
encrypted	O
disk	O
images	O
,	O
in	O
a	O
similar	O
manner	O
as	O
ZIP	B-General_Concept
and	O
RAR	O
archives	O
,	O
by	O
using	O
a	O
Windows	B-Protocol
Explorer	I-Protocol
like	O
interface	O
.	O
</s>
<s>
Due	O
to	O
its	O
architecture	O
,	O
FreeOTFE	B-Application
provides	O
great	O
flexibility	O
to	O
the	O
user	O
with	O
its	O
encryption	O
options	O
.	O
</s>
<s>
FreeOTFE	B-Application
implements	O
several	O
ciphers	O
,	O
including	O
:	O
</s>
<s>
It	O
includes	O
all	O
National	O
Institute	O
of	O
Standards	O
and	O
Technology	O
(	O
NIST	O
)	O
Advanced	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
(	O
AES	B-Algorithm
)	O
finalists	O
,	O
and	O
all	O
ciphers	O
can	O
be	O
used	O
with	O
multiple	O
different	O
keylengths	O
.	O
</s>
<s>
FreeOTFE	B-Application
originally	O
offered	O
encryption	O
using	O
cipher-block	O
chaining	O
(	O
CBC	O
)	O
with	O
encrypted	O
salt-sector	O
initialization	O
vector	O
(	O
ESSIV	O
)	O
,	O
though	O
from	O
v3.00	O
introduced	O
LRW	O
and	O
also	O
the	O
more	O
secure	O
XTS	O
mode	O
,	O
which	O
supersedes	O
LRW	O
in	O
the	O
IEEE	O
P1619	O
standard	O
for	O
disk	O
encryption	O
.	O
</s>
<s>
As	O
with	O
its	O
cipher	O
options	O
,	O
FreeOTFE	B-Application
offers	O
many	O
different	O
hash	O
algorithms	O
:	O
</s>
