<s>
Surespot	B-Protocol
was	O
a	O
free	O
open-source	B-Application
instant	B-Application
messaging	I-Application
application	O
for	O
Android	B-Application
and	O
iOS	B-Application
with	O
a	O
focus	O
on	O
privacy	O
and	O
security	O
.	O
</s>
<s>
The	O
application	O
supported	O
the	O
sending	O
of	O
text	O
,	O
pictures	O
,	O
audio	O
messages	O
(	O
in	O
the	O
past	O
only	O
after	O
an	O
in-app	O
purchase	O
)	O
,	O
and	O
Emoji	B-Application
icons	O
.	O
</s>
<s>
Surespot	B-Protocol
provided	O
offline	O
backup	O
via	O
iTunes	B-Operating_System
(	O
PC	O
or	O
Mac	O
)	O
on	O
the	O
iOS	B-Application
version	O
,	O
or	O
to	O
local	O
device	O
storage	O
on	O
the	O
Android	B-Application
version	O
.	O
</s>
<s>
For	O
secure	O
communication	O
,	O
Surespot	B-Protocol
used	O
end-to-end	O
encryption	O
by	O
default	O
.	O
</s>
<s>
256-bit	O
AES-GCM	B-Algorithm
encryption	O
was	O
used	O
,	O
with	O
keys	O
created	O
with	O
512-bit	O
ECDH	B-Protocol
.	O
</s>
<s>
Surespot	B-Protocol
was	O
donationware	B-License
.	O
</s>
<s>
As	O
of	O
November	O
4	O
,	O
2014	O
,	O
Surespot	B-Protocol
had	O
a	O
score	O
of	O
5	O
out	O
of	O
7	O
points	O
on	O
the	O
Electronic	O
Frontier	O
Foundation	O
secure	O
messaging	O
scorecard	O
.	O
</s>
<s>
It	O
had	O
received	O
points	O
for	O
having	O
communications	O
encrypted	O
in	O
transit	O
,	O
having	O
communications	O
encrypted	O
with	O
keys	O
the	O
provider	O
does	O
n't	O
have	O
access	O
to	O
(	O
end-to-end	O
encryption	O
)	O
,	O
making	O
it	O
possible	O
for	O
users	O
to	O
independently	O
verify	O
their	O
correspondent	O
's	O
identities	O
,	O
having	O
its	O
code	O
open	O
to	O
independent	O
review	O
(	O
open-source	B-Application
)	O
,	O
and	O
for	O
having	O
its	O
security	O
design	O
well-documented	O
.	O
</s>
<s>
In	O
May	O
2015	O
,	O
Channel	O
4	O
News	O
published	O
an	O
investigation	O
in	O
which	O
they	O
alleged	O
that	O
"	O
at	O
least	O
115	O
ISIS-linked	O
people	O
"	O
appeared	O
to	O
have	O
used	O
Surespot	B-Protocol
between	O
November	O
2014	O
and	O
May	O
2015	O
.	O
</s>
<s>
In	O
June	O
2015	O
,	O
a	O
Surespot	B-Protocol
user	O
wrote	O
a	O
blog	O
post	O
about	O
how	O
the	O
Surespot	B-Protocol
developers	O
had	O
stopped	O
responding	O
to	O
his	O
repeated	O
questions	O
regarding	O
"	O
governmental	O
demands	O
for	O
information	O
"	O
,	O
leading	O
to	O
the	O
user	O
alleging	O
that	O
the	O
Surespot	B-Protocol
developers	O
were	O
"	O
under	O
a	O
gag	O
order	O
"	O
.	O
</s>
<s>
Surespot	B-Protocol
was	O
specifically	O
mentioned	O
in	O
a	O
plea	O
agreement	O
in	O
which	O
a	O
17-year-old	O
US	O
citizen	O
was	O
charged	O
with	O
providing	O
material	O
support	O
to	O
ISIS	O
.	O
</s>
