<s>
EncFS	B-Application
is	O
a	O
Free	B-Application
(	O
LGPL	B-Application
)	O
FUSE-based	O
cryptographic	B-Application
filesystem	I-Application
.	O
</s>
<s>
Two	O
directories	O
are	O
involved	O
in	O
mounting	B-Application
an	O
EncFS	B-Application
filesystem	B-Application
:	O
the	O
source	O
directory	O
,	O
and	O
the	O
mountpoint	O
.	O
</s>
<s>
In	O
Linux	B-Application
,	O
allows	O
encryption	O
of	O
home	O
folders	O
as	O
an	O
alternative	O
to	O
eCryptfs	O
.	O
</s>
<s>
Allows	O
encryption	O
of	O
files	O
and	O
folders	O
saved	O
to	O
cloud	O
storage	O
(	O
Dropbox	B-Application
,	O
Google	B-Application
Drive	I-Application
,	O
OneDrive	B-Application
,	O
etc	O
.	O
</s>
<s>
Available	O
as	O
a	O
cross-platform	O
folder	B-Application
encryption	I-Application
mechanism	O
.	O
</s>
<s>
When	O
the	O
EncFS	B-Application
volume	O
key	O
is	O
stored	O
outside	O
the	O
encrypted	O
source	O
directory	O
and	O
into	O
a	O
physically	O
separated	O
location	O
from	O
the	O
actual	O
encrypted	O
data	O
,	O
it	O
significantly	O
increases	O
security	O
by	O
adding	O
a	O
two-factor	O
authentication	O
(	O
2FA	O
)	O
.	O
</s>
<s>
For	O
example	O
,	O
EncFS	B-Application
is	O
able	O
to	O
store	O
each	O
unique	O
volume	O
key	O
anywhere	O
else	O
than	O
the	O
actual	O
encrypted	O
data	O
,	O
such	O
as	O
on	O
a	O
USB	O
flash	O
drive	O
,	O
network	B-Application
mount	I-Application
,	O
optical	B-Device
disc	I-Device
or	O
cloud	O
.	O
</s>
<s>
EncFS	B-Application
offers	O
several	O
advantages	O
over	O
other	O
disk	O
encryption	O
software	O
simply	O
because	O
each	O
file	O
is	O
stored	O
individually	O
as	O
an	O
encrypted	O
file	O
elsewhere	O
in	O
the	O
host	O
's	O
directory	O
tree	O
.	O
</s>
<s>
EncFS	B-Application
's	O
encrypted	O
directory	O
can	O
be	O
located	O
on	O
a	O
normal	O
file	O
server	O
(	O
via	O
NFS	B-Protocol
,	O
SSHFS	B-Application
,	O
etc	O
.	O
)	O
</s>
<s>
Corruption	O
of	O
filedata	O
is	O
local	O
to	O
a	O
single	O
file	O
,	O
and	O
data	O
corruption	O
of	O
the	O
filesystem	B-Application
can	O
be	O
corrected	O
with	O
a	O
reliable	O
filesystem	B-Application
repair	O
utility	O
like	O
fsck	B-Device
.	O
</s>
<s>
Since	O
file	O
modifications	O
shine	O
through	O
to	O
the	O
underlying	O
file	B-Application
system	I-Application
,	O
various	O
optimizations	O
by	O
the	O
operating	O
system	O
are	O
still	O
possible	O
unlike	O
with	O
full-disk	O
encryption	O
.	O
</s>
<s>
For	O
example	O
,	O
passing	O
information	O
about	O
released	O
space	O
(	O
TRIM	O
)	O
can	O
improve	O
performance	O
of	O
SSD	B-Device
drives	I-Device
.	O
</s>
<s>
There	O
are	O
some	O
drawbacks	O
to	O
using	O
EncFS	B-Application
.	O
</s>
<s>
Mounted	O
EncFS	B-Application
directories	O
share	O
the	O
same	O
features	O
and	O
restrictions	O
as	O
the	O
filesystem	B-Application
containing	O
the	O
source	O
directory	O
.	O
</s>
<s>
Due	O
to	O
encryption	O
,	O
the	O
filenames	O
for	O
encrypted	O
files	O
produced	O
by	O
EncFS	B-Application
are	O
longer	O
than	O
the	O
original	O
filenames	O
.	O
</s>
<s>
Therefore	O
,	O
filenames	O
whose	O
length	O
is	O
close	O
to	O
the	O
maximum	O
supported	O
by	O
the	O
filesystem	B-Application
cannot	O
be	O
stored	O
by	O
EncFS	B-Application
,	O
since	O
they	O
will	O
exceed	O
the	O
length	O
limit	O
after	O
encryption	O
.	O
</s>
<s>
Most	O
filesystems	B-Application
limit	O
filenames	O
to	O
255	O
bytes	O
;	O
in	O
that	O
case	O
,	O
EncFS	B-Application
only	O
supports	O
filenames	O
up	O
to	O
190	O
bytes	O
.	O
</s>
<s>
Anyone	O
having	O
access	O
to	O
the	O
source	O
directory	O
is	O
able	O
to	O
see	O
how	O
many	O
files	O
are	O
in	O
the	O
encrypted	O
filesystem	B-Application
,	O
what	O
permissions	O
they	O
have	O
,	O
their	O
approximate	O
size	O
,	O
and	O
the	O
last	O
time	O
they	O
were	O
accessed	O
or	O
modified	O
,	O
though	O
the	O
file	O
names	O
and	O
file	O
data	O
are	O
encrypted	O
.	O
</s>
<s>
The	O
announcement	O
of	O
EncFS	B-Application
1.8	O
included	O
several	O
underlying	O
design	O
changes	O
,	O
acknowledging	O
the	O
security	O
concerns	O
raised	O
in	O
the	O
previous	O
audit	O
.	O
</s>
<s>
When	O
creating	O
a	O
new	O
EncFS	B-Application
volume	O
,	O
several	O
different	O
options	O
are	O
available	O
to	O
customize	O
the	O
filesystem	B-Application
to	O
suit	O
various	O
needs	O
.	O
</s>
<s>
EncFS	B-Application
uses	O
whatever	O
ciphers	O
it	O
is	O
able	O
to	O
locate	O
in	O
various	O
encryption	O
libraries	O
on	O
the	O
system	O
.	O
</s>
<s>
Blowfish	B-Algorithm
and	O
AES	B-Algorithm
are	O
typically	O
available	O
.	O
</s>
<s>
Block	O
mode	O
obscures	O
the	O
filename	O
length	O
somewhat	O
,	O
while	O
stream	O
mode	O
keeps	O
them	O
as	O
short	O
as	O
possible	O
,	O
which	O
might	O
save	O
space	O
on	O
the	O
source	O
directory	O
's	O
filesystem	B-Application
depending	O
on	O
how	O
that	O
filesystem	B-Application
manages	O
the	O
directory	O
tree	O
.	O
</s>
<s>
When	O
enabled	O
,	O
the	O
initialization	B-Algorithm
vector	I-Algorithm
for	O
filename	O
encryption	O
is	O
derived	O
from	O
the	O
file	O
's	O
parent	O
directories	O
,	O
causing	O
two	O
files	O
with	O
the	O
same	O
name	O
but	O
in	O
different	O
directories	O
to	O
have	O
different	O
encrypted	O
filenames	O
.	O
</s>
<s>
When	O
enabled	O
,	O
each	O
file	O
is	O
encrypted	O
with	O
a	O
random	O
8-byte	O
initialization	B-Algorithm
vector	I-Algorithm
,	O
which	O
is	O
stored	O
within	O
the	O
encrypted	O
file	O
in	O
the	O
source	O
directory	O
.	O
</s>
<s>
If	O
this	O
option	O
is	O
disabled	O
,	O
each	O
file	O
is	O
encrypted	O
with	O
the	O
same	O
initialization	B-Algorithm
vector	I-Algorithm
,	O
which	O
can	O
make	O
the	O
volume	O
key	O
easier	O
to	O
break	O
.	O
</s>
<s>
Enabling	O
this	O
option	O
makes	O
the	O
filesystem	B-Application
more	O
secure	O
at	O
the	O
cost	O
of	O
an	O
additional	O
8	O
bytes	O
per	O
file	O
.	O
</s>
<s>
Causes	O
the	O
file	O
data	O
initialization	B-Algorithm
vector	I-Algorithm
to	O
be	O
derived	O
from	O
the	O
filename	O
's	O
initialization	B-Algorithm
vector	I-Algorithm
chain	O
.	O
</s>
<s>
Consequently	O
,	O
renaming	O
a	O
file	O
when	O
this	O
mode	O
is	O
enabled	O
requires	O
that	O
either	O
the	O
file	O
's	O
random	O
initialization	B-Algorithm
vector	I-Algorithm
be	O
offset	O
by	O
the	O
change	O
in	O
the	O
filename	O
initialization	B-Algorithm
vector	I-Algorithm
chain	O
,	O
or	O
the	O
data	O
be	O
re-encoded	O
.	O
</s>
<s>
The	O
authors	O
of	O
EncFS	B-Application
have	O
chosen	O
the	O
former	O
route	O
as	O
it	O
is	O
considerably	O
faster	O
,	O
especially	O
for	O
large	O
files	O
.	O
</s>
<s>
Stores	O
a	O
checksum	O
with	O
each	O
encrypted	O
block	O
,	O
causing	O
corruption	O
or	O
modification	O
of	O
the	O
encrypted	O
files	O
to	O
be	O
detected	O
by	O
EncFS	B-Application
.	O
</s>
<s>
This	O
option	O
creates	O
a	O
large	O
amount	O
of	O
CPU	B-General_Concept
overhead	O
,	O
as	O
each	O
block	O
's	O
checksum	O
must	O
be	O
calculated	O
when	O
data	O
is	O
read	O
(	O
to	O
verify	O
integrity	O
)	O
or	O
written	O
(	O
to	O
update	O
the	O
checksum	O
)	O
.	O
</s>
