<s>
The	O
LOCKSS	B-Application
(	O
"	O
Lots	B-Application
of	I-Application
Copies	I-Application
Keep	I-Application
Stuff	I-Application
Safe	I-Application
"	O
)	O
project	O
,	O
under	O
the	O
auspices	O
of	O
Stanford	O
University	O
,	O
is	O
a	O
peer-to-peer	O
network	O
that	O
develops	O
and	O
supports	O
an	O
open	B-Application
source	I-Application
system	O
allowing	O
libraries	O
to	O
collect	O
,	O
preserve	O
and	O
provide	O
their	O
readers	O
with	O
access	O
to	O
material	O
published	O
on	O
the	O
Web	O
.	O
</s>
<s>
A	O
similar	O
project	O
called	O
CLOCKSS	B-Application
(	O
Controlled	O
LOCKSS	B-Application
)	O
"	O
is	O
a	O
tax-exempt	O
,	O
501(c )	O
3	O
,	O
not-for-profit	O
organization	O
,	O
governed	O
by	O
a	O
Board	O
of	O
Directors	O
made	O
up	O
of	O
librarians	O
and	O
publishers.	O
"	O
</s>
<s>
CLOCKSS	B-Application
runs	O
on	O
LOCKSS	B-Application
technology	O
.	O
</s>
<s>
The	O
LOCKSS	B-Application
system	O
allows	O
a	O
library	O
,	O
with	O
permission	O
from	O
the	O
publisher	O
,	O
to	O
collect	O
,	O
preserve	O
and	O
disseminate	O
to	O
its	O
patrons	O
a	O
copy	O
of	O
the	O
materials	O
to	O
which	O
it	O
has	O
subscribed	O
as	O
well	O
as	O
open	O
access	O
material	O
(	O
perhaps	O
published	O
under	O
a	O
Creative	O
Commons	O
license	O
)	O
.	O
</s>
<s>
Each	O
library	O
's	O
system	O
collects	O
a	O
copy	O
using	O
a	O
specialized	O
web	B-Application
crawler	I-Application
that	O
verifies	O
that	O
the	O
publisher	O
has	O
granted	O
suitable	O
permission	O
.	O
</s>
<s>
The	O
system	O
is	O
format-agnostic	O
,	O
collecting	O
whatever	O
formats	O
the	O
publisher	O
delivers	O
via	O
HTTP	B-Protocol
.	I-Protocol
</s>
<s>
Peers	O
in	O
the	O
network	O
vote	O
on	O
cryptographic	B-Algorithm
hash	I-Algorithm
functions	I-Algorithm
of	O
preserved	O
content	O
and	O
a	O
nonce	O
;	O
a	O
peer	O
that	O
is	O
outvoted	O
regards	O
its	O
copy	O
as	O
damaged	O
and	O
repairs	O
it	O
from	O
the	O
publisher	O
or	O
other	O
peers	O
.	O
</s>
<s>
The	O
LOCKSS	B-Application
license	O
used	O
by	O
most	O
publishers	O
allows	O
a	O
library	O
's	O
readers	O
access	O
to	O
its	O
own	O
copy	O
,	O
but	O
does	O
not	O
allow	O
similar	O
access	O
to	O
other	O
libraries	O
or	O
unaffiliated	O
readers	O
;	O
the	O
system	O
does	O
not	O
support	O
file	O
sharing	O
.	O
</s>
<s>
The	O
LOCKSS	B-Application
approach	O
of	O
selective	O
collection	O
with	O
permission	O
from	O
the	O
publisher	O
,	O
distributed	O
storage	O
,	O
and	O
restricted	O
dissemination	O
contrasts	O
with	O
,	O
for	O
example	O
,	O
the	O
Internet	O
Archive	O
's	O
approach	O
of	O
omnivorous	O
collection	O
without	O
permission	O
from	O
the	O
publisher	O
,	O
centralized	O
storage	O
,	O
and	O
unrestricted	O
dissemination	O
.	O
</s>
<s>
The	O
LOCKSS	B-Application
system	O
is	O
far	O
smaller	O
,	O
but	O
it	O
can	O
preserve	O
subscription	O
materials	O
to	O
which	O
the	O
Internet	O
Archive	O
has	O
no	O
access	O
.	O
</s>
<s>
Since	O
each	O
library	O
administers	O
its	O
own	O
LOCKSS	B-Application
peer	O
and	O
maintains	O
its	O
own	O
copy	O
of	O
preserved	O
material	O
,	O
and	O
since	O
there	O
are	O
libraries	O
doing	O
so	O
worldwide	O
(	O
see	O
the	O
list	O
of	O
participating	O
libraries	O
below	O
)	O
,	O
the	O
system	O
provides	O
a	O
much	O
higher	O
degree	O
of	O
replication	B-Architecture
than	O
is	O
usual	O
in	O
a	O
fault-tolerant	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
voting	O
process	O
makes	O
use	O
of	O
this	O
high	O
degree	O
of	O
replication	B-Architecture
to	O
eliminate	O
the	O
need	O
for	O
backups	B-Protocol
to	O
off-line	O
media	O
,	O
and	O
to	O
provide	O
robust	O
defenses	O
against	O
attacks	O
aimed	O
at	O
corrupting	O
preserved	O
content	O
.	O
</s>
<s>
By	O
preserving	O
many	O
copies	O
under	O
diverse	O
administration	O
,	O
by	O
automatically	O
auditing	O
the	O
copies	O
at	O
intervals	O
against	O
each	O
other	O
(	O
and	O
,	O
in	O
the	O
future	O
,	O
against	O
the	O
publisher	O
's	O
copy	O
)	O
,	O
and	O
by	O
alerting	O
libraries	O
when	O
changes	O
are	O
detected	O
,	O
the	O
LOCKSS	B-Application
system	O
attempts	O
to	O
restore	O
many	O
of	O
these	O
safeguards	O
in	O
the	O
now	O
digital	O
world	O
of	O
publication	O
.	O
</s>
<s>
Prior	O
to	O
implementing	O
a	O
LOCKSS	B-Application
system	O
,	O
some	O
questions	O
need	O
to	O
be	O
considered	O
carefully	O
in	O
order	O
to	O
make	O
sure	O
the	O
content	O
is	O
verified	O
,	O
evaluated	O
,	O
and	O
auditable	O
by	O
users	O
.	O
</s>
<s>
The	O
source	O
code	O
for	O
the	O
entire	O
LOCKSS	B-Application
system	O
carries	O
BSD-style	O
open-source	B-Application
licenses	O
and	O
is	O
available	O
from	O
GitHub	B-Application
.	O
</s>
<s>
LOCKSS	B-Application
is	O
a	O
trademark	O
of	O
Stanford	O
University	O
.	O
</s>
