<s>
Nettle	B-Application
is	O
a	O
cryptographic	O
library	O
designed	O
to	O
fit	O
easily	O
in	O
a	O
wide	O
range	O
of	O
toolkits	O
and	O
applications	O
.	O
</s>
<s>
It	O
began	O
as	O
a	O
collection	O
of	O
low-level	O
cryptography	O
functions	O
from	O
lsh	B-Algorithm
in	O
2001	O
.	O
</s>
<s>
Since	O
June	O
2009	O
(	O
version	O
2.0	O
)	O
Nettle	B-Application
is	O
a	O
GNU	O
package	O
.	O
</s>
<s>
Since	O
version	O
3	O
,	O
nettle	B-Application
provides	O
the	O
AES	B-Algorithm
block	O
cipher	O
(	O
a	O
subset	O
of	O
Rijndael	B-Algorithm
)	O
(	O
with	O
assembly	O
optimizations	O
for	O
x86	O
and	O
sparc	O
)	O
,	O
the	O
ARCFOUR	B-Algorithm
(	O
also	O
known	O
as	O
RC4	B-Algorithm
)	O
stream	B-Algorithm
cipher	I-Algorithm
(	O
with	O
x86	O
and	O
sparc	O
assembly	O
)	O
,	O
the	O
ARCTWO	B-Algorithm
(	O
also	O
known	O
as	O
RC2	B-Algorithm
)	O
stream	B-Algorithm
cipher	I-Algorithm
,	O
BLOWFISH	B-Algorithm
,	O
CAMELLIA	B-Algorithm
(	O
with	O
x86	O
and	O
x86_64	O
assembly	O
optimizations	O
)	O
,	O
CAST-128	B-Algorithm
,	O
DES	B-Algorithm
and	O
3DES	B-Algorithm
block	O
ciphers	O
,	O
the	O
ChaCha	O
stream	B-Algorithm
cipher	I-Algorithm
(	O
with	O
assembly	O
for	O
x86_64	O
)	O
,	O
GOSTHASH94	B-Algorithm
,	O
the	O
MD2	B-Algorithm
,	O
MD4	B-Algorithm
,	O
and	O
MD5	B-Algorithm
(	O
with	O
x86	O
assembly	O
)	O
digests	B-Algorithm
,	O
the	O
PBKDF2	O
key	B-Algorithm
derivation	I-Algorithm
function	I-Algorithm
,	O
the	O
POLY1305	B-Algorithm
(	O
with	O
assembly	O
for	O
x86_64	O
)	O
and	O
UMAC	B-Algorithm
message	B-Algorithm
authentication	I-Algorithm
codes	I-Algorithm
,	O
RIPEMD160	B-Algorithm
,	O
the	O
Salsa20	B-Algorithm
stream	B-Algorithm
cipher	I-Algorithm
(	O
with	O
assembly	O
for	O
x86_64	O
and	O
ARM	O
)	O
,	O
the	O
SERPENT	B-Algorithm
block	O
cipher	O
(	O
with	O
assembly	O
for	O
x86_64	O
)	O
,	O
SHA-1	B-Algorithm
(	O
with	O
x86	O
,	O
x86_64	O
and	O
ARM	O
assembly	O
)	O
,	O
the	O
SHA-2	B-Algorithm
(	O
SHA-224	B-Algorithm
,	O
SHA-256	B-Algorithm
,	O
SHA-384	B-Algorithm
,	O
and	O
SHA-512	B-Algorithm
)	O
digests	B-Algorithm
,	O
SHA-3	B-Algorithm
(	O
a	O
subset	O
of	O
the	O
Keccak	B-Algorithm
digest	O
family	O
)	O
,	O
the	O
TWOFISH	B-Algorithm
block	O
cipher	O
,	O
RSA	B-Architecture
,	O
DSA	O
and	O
ECDSA	O
public-key	B-Application
algorithms	I-Application
,	O
the	O
Yarrow	B-Algorithm
pRNG	B-Algorithm
.	O
</s>
<s>
Version	O
3.1	O
introduced	O
support	O
for	O
Curve25519	O
and	O
EdDSA	B-Algorithm
operations	O
.	O
</s>
<s>
The	O
public-key	B-Application
algorithms	I-Application
use	O
GMP	B-Application
.	O
</s>
<s>
Nettle	B-Application
is	O
used	O
by	O
GnuTLS	B-Application
.	O
</s>
<s>
Nettle	B-Application
is	O
an	O
attempt	O
to	O
avoid	O
this	O
problem	O
by	O
doing	O
one	O
thing	O
(	O
the	O
low-level	O
cryptography	O
)	O
and	O
providing	O
a	O
simple	O
and	O
general	O
interface	O
to	O
it	O
.	O
</s>
<s>
In	O
particular	O
,	O
Nettle	B-Application
does	O
n't	O
do	O
algorithm	O
selection	O
,	O
memory	O
allocation	O
or	O
any	O
I/O	O
.	O
</s>
<s>
Thus	O
Nettle	B-Application
is	O
intended	O
to	O
provide	O
a	O
core	O
cryptography	O
library	O
upon	O
which	O
numerous	O
application	O
and	O
context	O
specific	O
interfaces	O
can	O
be	O
built	O
.	O
</s>
<s>
of	O
these	O
interfaces	O
can	O
then	O
be	O
shared	O
without	O
having	O
to	O
replicate	O
Nettle	B-Application
's	O
cryptographic	O
code	O
.	O
</s>
<s>
Nettle	B-Application
is	O
primarily	O
licensed	O
under	O
a	O
dual	O
licence	O
scheme	O
comprising	O
The	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
version	O
2	O
or	O
later	O
and	O
The	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
version	O
3	O
or	O
later	O
.	O
</s>
<s>
A	O
few	O
individual	O
files	O
are	O
licensed	O
under	O
more	O
permissive	B-License
licences	I-License
or	O
in	O
the	O
public	O
domain	O
.	O
</s>
<s>
The	O
Nettle	B-Application
manual	O
"	O
is	O
in	O
the	O
public	O
domain	O
"	O
and	O
may	O
be	O
used	O
and	O
reproduced	O
freely	O
.	O
</s>
