<s>
The	O
Secure	B-Protocol
Remote	I-Protocol
Password	I-Protocol
protocol	I-Protocol
(	O
SRP	O
)	O
is	O
an	O
augmented	O
password-authenticated	B-Protocol
key	I-Protocol
exchange	I-Protocol
(	O
PAKE	B-Protocol
)	O
protocol	O
,	O
specifically	O
designed	O
to	O
work	O
around	O
existing	O
patents	O
.	O
</s>
<s>
Like	O
all	O
PAKE	B-Protocol
protocols	O
,	O
an	O
eavesdropper	O
or	O
man	O
in	O
the	O
middle	O
cannot	O
obtain	O
enough	O
information	O
to	O
be	O
able	O
to	O
brute-force	O
guess	O
a	O
password	O
or	O
apply	O
a	O
dictionary	O
attack	O
without	O
further	O
interactions	O
with	O
the	O
parties	O
for	O
each	O
guess	O
.	O
</s>
<s>
Furthermore	O
,	O
being	O
an	O
augmented	O
PAKE	B-Protocol
protocol	O
,	O
the	O
server	O
does	O
not	O
store	O
password-equivalent	O
data	O
.	O
</s>
<s>
In	O
layman	O
's	O
terms	O
,	O
during	O
SRP	O
(	O
or	O
any	O
other	O
PAKE	B-Protocol
protocol	O
)	O
authentication	O
,	O
one	O
party	O
(	O
the	O
"	O
client	O
"	O
or	O
"	O
user	O
"	O
)	O
demonstrates	O
to	O
another	O
party	O
(	O
the	O
"	O
server	O
"	O
)	O
that	O
they	O
know	O
the	O
password	O
,	O
without	O
sending	O
the	O
password	O
itself	O
nor	O
any	O
other	O
information	O
from	O
which	O
the	O
password	O
can	O
be	O
derived	O
.	O
</s>
<s>
The	O
SRP	B-Protocol
protocol	I-Protocol
has	O
a	O
number	O
of	O
desirable	O
properties	O
:	O
it	O
allows	O
a	O
user	O
to	O
authenticate	O
themselves	O
to	O
a	O
server	O
,	O
it	O
is	O
resistant	O
to	O
dictionary	O
attacks	O
mounted	O
by	O
an	O
eavesdropper	O
,	O
and	O
it	O
does	O
not	O
require	O
a	O
trusted	O
third	O
party	O
.	O
</s>
<s>
It	O
effectively	O
conveys	O
a	O
zero-knowledge	B-General_Concept
password	I-General_Concept
proof	I-General_Concept
from	O
the	O
user	O
to	O
the	O
server	O
.	O
</s>
<s>
The	O
SRP	B-Protocol
protocol	I-Protocol
has	O
been	O
revised	O
several	O
times	O
,	O
and	O
is	O
currently	O
at	O
revision	O
6a	O
.	O
</s>
<s>
The	O
SRP	B-Protocol
protocol	I-Protocol
creates	O
a	O
large	O
private	O
key	O
shared	O
between	O
the	O
two	O
parties	O
in	O
a	O
manner	O
similar	O
to	O
Diffie	B-Protocol
–	I-Protocol
Hellman	I-Protocol
key	I-Protocol
exchange	I-Protocol
based	O
on	O
the	O
client	O
side	O
having	O
the	O
user	O
password	O
and	O
the	O
server	O
side	O
having	O
a	O
cryptographic	O
verifier	O
derived	O
from	O
the	O
password	O
.	O
</s>
<s>
In	O
cases	O
where	O
encrypted	O
communications	O
as	O
well	O
as	O
authentication	O
are	O
required	O
,	O
the	O
SRP	B-Protocol
protocol	I-Protocol
is	O
more	O
secure	O
than	O
the	O
alternative	O
SSH	B-Protocol
protocol	O
and	O
faster	O
than	O
using	O
Diffie	B-Protocol
–	I-Protocol
Hellman	I-Protocol
key	I-Protocol
exchange	I-Protocol
with	O
signed	O
messages	O
.	O
</s>
<s>
It	O
is	O
also	O
independent	O
of	O
third	O
parties	O
,	O
unlike	O
Kerberos	B-Protocol
.	O
</s>
<s>
The	O
SRP	B-Protocol
protocol	I-Protocol
,	O
version	O
3	O
is	O
described	O
in	O
RFC	O
2945	O
.	O
</s>
<s>
SRP	O
version	O
6	O
is	O
also	O
used	O
for	O
strong	O
password	O
authentication	O
in	O
SSL/TLS	B-Protocol
(	O
in	O
TLS-SRP	B-Protocol
)	O
and	O
other	O
standards	O
such	O
as	O
EAP	B-Protocol
and	O
SAML	O
,	O
and	O
is	O
being	O
standardized	O
in	O
IEEE	O
P1363	O
and	O
ISO/IEC	O
11770-4	O
.	O
</s>
<s>
H( )	O
is	O
a	O
hash	B-Algorithm
function	I-Algorithm
;	O
e.g.	O
,	O
SHA-256	O
.	O
</s>
<s>
While	O
most	O
of	O
the	O
additional	O
state	O
is	O
public	O
,	O
private	O
information	O
could	O
safely	O
be	O
added	O
to	O
the	O
inputs	O
to	O
the	O
hash	B-Algorithm
function	I-Algorithm
,	O
like	O
the	O
server	O
private	O
key	O
.	O
</s>
<s>
A	O
Java	B-Language
library	O
of	O
cryptographic	O
primitives	O
required	O
to	O
implement	O
the	O
SRP-6	O
protocol	O
.	O
</s>
<s>
OpenSSL	B-Language
version	O
1.0.1	O
or	O
later	O
.	O
</s>
<s>
TLS-SRP	B-Protocol
is	O
a	O
set	O
of	O
ciphersuites	O
for	O
transport	B-Protocol
layer	I-Protocol
security	I-Protocol
that	O
uses	O
SRP	O
.	O
</s>
<s>
SRP-6a	O
implementation	O
in	O
JavaScript	B-Language
(	O
compatible	O
with	O
RFC	O
5054	O
)	O
,	O
open	O
source	O
,	O
Mozilla	B-License
Public	I-License
License	I-License
(	O
MPL	O
)	O
licensed	O
.	O
</s>
<s>
The	O
includes	O
a	O
JavaScript	B-Language
implementation	O
of	O
the	O
SRP	B-Protocol
protocol	I-Protocol
,	O
open	O
source	O
,	O
BSD	B-Operating_System
licensed	O
.	O
</s>
<s>
provide	O
a	O
Java	B-Language
implementation	O
licensed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
with	O
the	O
"	O
library	O
exception	O
"	O
,	O
which	O
permits	O
its	O
use	O
as	O
a	O
library	O
in	O
conjunction	O
with	O
non-Free	O
software	O
.	O
</s>
<s>
The	B-Language
Legion	I-Language
of	I-Language
the	I-Language
Bouncy	I-Language
Castle	I-Language
provides	O
Java	B-Language
and	O
C#	B-Application
implementations	O
under	O
the	B-License
MIT	I-License
License	I-License
.	O
</s>
<s>
is	O
a	O
Java	B-Language
library	O
providing	O
a	O
verifier	O
generator	O
,	O
client	O
and	O
server-side	O
sessions	O
.	O
</s>
<s>
Released	O
under	O
the	O
Apache	B-Application
2.0	I-Application
license	I-Application
.	O
</s>
<s>
is	O
a	O
C++	O
modular	O
implementation	O
currently	O
works	O
with	O
OpenSSL	B-Language
.	O
</s>
<s>
Json2Ldap	B-Language
provides	O
SRP-6a	O
authentication	O
to	O
LDAP	B-Protocol
directory	O
servers	O
.	O
</s>
<s>
SRP-6a	O
implementation	O
in	O
Perl	B-Language
.	O
</s>
<s>
SRP-6a	O
implementation	O
in	O
Python	B-Language
(	O
compatible	O
with	O
)	O
.	O
</s>
<s>
SRP-6a	O
implementation	O
in	O
pure	O
Python3	B-Language
.	O
</s>
<s>
Tools	O
to	O
implement	O
Secure	B-Protocol
Remote	I-Protocol
Password	I-Protocol
(	O
SRP	O
)	O
authentication	O
in	O
Python	B-Language
.	O
</s>
<s>
SRP-6a	O
implementation	O
in	O
Ruby	B-Language
.	O
</s>
<s>
implementation	O
of	O
the	O
Stanford	O
SRP	B-Protocol
Protocol	I-Protocol
Design	O
in	O
JavaScript	B-Language
and	O
PHP	B-Application
under	O
the	B-License
MIT	I-License
License	I-License
.	O
</s>
<s>
SRP-6a	O
implementation	O
in	O
PHP	B-Application
and	O
JavaScript	B-Language
.	O
</s>
<s>
SRP-6a	O
implementation	O
in	O
JavaScript	B-Language
.	O
</s>
<s>
Comes	O
with	O
compatible	O
Java	B-Language
classes	O
which	O
use	O
a	O
demonstration	O
app	O
using	O
Spring	B-Language
Security	I-Language
.	O
</s>
<s>
There	O
is	O
also	O
a	O
demonstration	O
application	O
performing	O
authentication	O
to	O
a	O
PHP	B-Application
server	O
.	O
</s>
<s>
Released	O
under	O
the	O
Apache	B-Application
License	I-Application
.	O
</s>
<s>
is	O
a	O
JavaScript	B-Language
client	O
and	O
server	O
(	O
node.js	O
)	O
implementation	O
of	O
SRP	O
.	O
</s>
<s>
implementation	O
in	O
C#	B-Application
and	O
Java	B-Language
.	O
</s>
<s>
Java	B-Language
library	O
to	O
develop	O
cryptography-based	O
Spring	O
Boot	O
applications	O
.	O
</s>
<s>
Under	O
Apache	B-Application
License	I-Application
.	O
</s>
