<s>
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
(	O
"	O
SP	O
"	O
stands	O
for	O
"	O
special	O
publication	O
"	O
)	O
is	O
a	O
publication	O
by	O
the	O
National	O
Institute	O
of	O
Standards	O
and	O
Technology	O
with	O
the	O
title	O
Recommendation	O
for	O
Random	O
Number	O
Generation	O
Using	O
Deterministic	O
Random	O
Bit	O
Generators	O
.	O
</s>
<s>
The	O
publication	O
contains	O
the	O
specification	O
for	O
three	O
allegedly	O
cryptographically	B-Algorithm
secure	I-Algorithm
pseudorandom	I-Algorithm
number	I-Algorithm
generators	I-Algorithm
for	O
use	O
in	O
cryptography	O
:	O
Hash	B-Error_Name
DRBG	O
(	O
based	O
on	O
hash	B-Error_Name
functions	I-Error_Name
)	O
,	O
HMAC	B-Algorithm
DRBG	O
(	O
based	O
on	O
HMAC	B-Algorithm
)	O
,	O
and	O
CTR	O
DRBG	O
(	O
based	O
on	O
block	O
ciphers	O
in	O
counter	O
mode	O
)	O
.	O
</s>
<s>
As	O
a	O
work	O
of	O
the	O
US	O
Federal	O
Government	O
,	O
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
is	O
in	O
the	O
public	O
domain	O
and	O
freely	O
available	O
.	O
</s>
<s>
In	O
getting	O
Dual_EC_DRBG	O
accepted	O
into	O
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
,	O
NSA	O
cited	O
prominent	O
security	O
firm	O
RSA	O
Security	O
's	O
usage	O
of	O
Dual_EC_DRBG	O
in	O
their	O
products	O
.	O
</s>
<s>
As	O
the	O
$10	O
million	O
contract	O
to	O
get	O
RSA	O
Security	O
to	O
use	O
Dual_EC_DRBG	O
was	O
described	O
by	O
Reuters	O
as	O
secret	O
,	O
the	O
people	O
involved	O
in	O
the	O
process	O
of	O
accepting	O
Dual_EC_DRBG	O
into	O
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
were	O
presumably	O
not	O
made	O
aware	O
of	O
this	O
obvious	O
conflict	O
of	O
interest	O
.	O
</s>
<s>
This	O
might	O
help	O
explain	O
how	O
a	O
random	O
number	O
generator	O
later	O
shown	O
to	O
be	O
inferior	O
to	O
the	O
alternatives	O
(	O
in	O
addition	O
to	O
the	O
back	O
door	O
)	O
made	O
it	O
into	O
the	O
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
standard	O
.	O
</s>
<s>
Following	O
the	O
NSA	O
backdoor	O
revelation	O
,	O
NIST	O
has	O
reopened	O
the	O
public	O
vetting	O
process	O
for	O
the	O
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
standard	O
.	O
</s>
<s>
A	O
revised	O
version	O
of	O
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
that	O
removes	O
Dual_EC_DRBG	O
was	O
published	O
in	O
June	O
2015	O
.	O
</s>
<s>
The	O
paper	O
proving	O
the	O
security	O
of	O
Hash_DRBG	O
and	O
HMAC_DRBG	O
does	O
cite	O
the	O
attempted	O
security	O
proof	O
for	O
Dual_EC_DRBG	O
used	O
in	O
the	O
previous	O
paragraph	O
as	O
a	O
security	O
proof	O
to	O
say	O
that	O
one	O
should	O
not	O
use	O
CTR_DRBG	O
because	O
it	O
is	O
the	O
only	O
DRBG	O
in	O
NIST	B-Algorithm
SP	I-Algorithm
800-90A	I-Algorithm
that	O
lacks	O
a	O
security	O
proof	O
.	O
</s>
<s>
CTR_DRBG	O
is	O
also	O
shown	O
to	O
fail	O
to	O
deliver	O
the	O
expected	O
security	O
level	O
whenever	O
Triple	B-Algorithm
DES	I-Algorithm
is	O
used	O
because	O
its	O
64-bit	O
block	O
size	O
is	O
much	O
less	O
than	O
the	O
112-bit	O
key	O
size	O
used	O
for	O
Triple	B-Algorithm
DES	I-Algorithm
.	O
</s>
