<s>
is	O
a	O
computer	B-Application
program	I-Application
that	O
calculates	O
and	O
verifies	O
128-bit	O
MD5	B-Algorithm
hashes	I-Algorithm
,	O
as	O
described	O
in	O
RFC	O
1321	O
.	O
</s>
<s>
The	O
MD5	B-Algorithm
hash	I-Algorithm
functions	O
as	O
a	O
compact	O
digital	O
fingerprint	O
of	O
a	O
file	O
.	O
</s>
<s>
As	O
with	O
all	O
such	O
hashing	O
algorithms	O
,	O
there	O
is	O
theoretically	O
an	O
unlimited	O
number	O
of	O
files	O
that	O
will	O
have	O
any	O
given	O
MD5	B-Algorithm
hash	I-Algorithm
.	O
</s>
<s>
However	O
,	O
it	O
is	O
very	O
unlikely	O
that	O
any	O
two	O
non-identical	O
files	O
in	O
the	O
real	O
world	O
will	O
have	O
the	O
same	O
MD5	B-Algorithm
hash	I-Algorithm
,	O
unless	O
they	O
have	O
been	O
specifically	O
created	O
to	O
have	O
the	O
same	O
hash	B-Algorithm
.	O
</s>
<s>
The	O
underlying	O
MD5	B-Algorithm
algorithm	O
is	O
no	O
longer	O
deemed	O
secure	O
.	O
</s>
<s>
is	O
used	O
to	O
verify	O
the	O
integrity	O
of	O
files	O
,	O
as	O
virtually	O
any	O
change	O
to	O
a	O
file	O
will	O
cause	O
its	O
MD5	B-Algorithm
hash	I-Algorithm
to	O
change	O
.	O
</s>
<s>
The	O
program	O
is	O
included	O
in	O
most	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
or	O
compatibility	B-General_Concept
layers	I-General_Concept
such	O
as	O
Cygwin	B-Language
.	O
</s>
<s>
File	O
contains	O
hash	B-Algorithm
and	O
filename	O
pairs	O
:	O
</s>
<s>
After	O
the	O
value	O
there	O
must	O
be	O
a	O
space	O
followed	O
by	O
either	O
a	O
second	O
space	O
(	O
for	O
text	O
mode	O
)	O
or	O
an	O
asterisk	O
(	O
for	O
binary	O
mode	O
)	O
;	O
otherwise	O
,	O
the	O
following	O
error	O
will	O
result	O
:	O
no	O
properly	O
formatted	O
MD5	B-Algorithm
checksum	O
lines	O
found	O
.	O
</s>
<s>
The	O
file	O
must	O
also	O
be	O
UNIX	B-Application
line	O
ending	O
formatted	O
,	O
otherwise	O
this	O
will	O
be	O
seen	O
:	O
md5sum	B-Device
:	O
WARNING	O
:	O
x	O
listed	O
files	O
could	O
not	O
be	O
read	O
.	O
</s>
<s>
is	O
specific	O
to	O
systems	O
that	O
use	O
GNU	B-Application
coreutils	I-Application
or	O
a	O
clone	O
such	O
as	O
BusyBox	B-Application
.	O
</s>
<s>
On	O
FreeBSD	B-Operating_System
and	O
OpenBSD	B-Operating_System
the	O
utilities	O
are	O
called	O
,	O
,	O
,	O
and	O
.	O
</s>
<s>
Additionally	O
,	O
FreeBSD	B-Operating_System
offers	O
the	O
"	O
SKEIN	O
"	O
family	O
of	O
message	B-Algorithm
digests	I-Algorithm
.	O
</s>
