<s>
Cloud	B-General_Concept
computing	I-General_Concept
security	I-General_Concept
or	O
,	O
more	O
simply	O
,	O
cloud	B-General_Concept
security	I-General_Concept
refers	O
to	O
a	O
broad	O
set	O
of	O
policies	O
,	O
technologies	O
,	O
applications	O
,	O
and	O
controls	O
utilized	O
to	O
protect	O
virtualized	B-General_Concept
IP	O
,	O
data	O
,	O
applications	O
,	O
services	O
,	O
and	O
the	O
associated	O
infrastructure	O
of	O
cloud	B-Architecture
computing	I-Architecture
.	O
</s>
<s>
Cloud	B-Architecture
computing	I-Architecture
and	O
storage	O
provide	O
users	O
with	O
capabilities	O
to	O
store	O
and	O
process	O
their	O
data	O
in	O
third-party	O
data	B-Operating_System
centers	I-Operating_System
.	O
</s>
<s>
Organizations	O
use	O
the	O
cloud	O
in	O
a	O
variety	O
of	O
different	O
service	O
models	O
(	O
with	O
acronyms	O
such	O
as	O
SaaS	B-Architecture
,	O
PaaS	B-Application
,	O
and	O
IaaS	B-General_Concept
)	O
and	O
deployment	O
models	O
(	O
private	O
,	O
public	O
,	O
hybrid	O
,	O
and	O
community	B-General_Concept
)	O
.	O
</s>
<s>
Security	O
concerns	O
associated	O
with	O
cloud	B-Architecture
computing	I-Architecture
are	O
typically	O
categorized	O
in	O
two	O
ways	O
:	O
as	O
security	O
issues	O
faced	O
by	O
cloud	O
providers	O
(	O
organizations	O
providing	O
software-	O
,	O
platform-	O
,	O
or	O
infrastructure-as-a-service	B-General_Concept
via	O
the	O
cloud	O
)	O
and	O
security	O
issues	O
faced	O
by	O
their	O
customers	O
(	O
companies	O
or	O
organizations	O
who	O
host	O
applications	O
or	O
store	O
data	O
on	O
the	O
cloud	O
)	O
.	O
</s>
<s>
According	O
to	O
a	O
2010	O
Cloud	B-General_Concept
Security	I-General_Concept
Alliance	O
report	O
,	O
insider	O
attacks	O
are	O
one	O
of	O
the	O
top	O
seven	O
biggest	O
threats	O
in	O
cloud	B-Architecture
computing	I-Architecture
.	O
</s>
<s>
Therefore	O
,	O
cloud	B-Architecture
service	I-Architecture
providers	I-Architecture
must	O
ensure	O
that	O
thorough	O
background	O
checks	O
are	O
conducted	O
for	O
employees	O
who	O
have	O
physical	O
access	O
to	O
the	O
servers	O
in	O
the	O
data	B-Operating_System
center	I-Operating_System
.	O
</s>
<s>
Additionally	O
,	O
data	B-Operating_System
centers	I-Operating_System
are	O
recommended	O
to	O
be	O
frequently	O
monitored	O
for	O
suspicious	O
activity	O
.	O
</s>
<s>
In	O
order	O
to	O
conserve	O
resources	O
,	O
cut	O
costs	O
,	O
and	O
maintain	O
efficiency	O
,	O
cloud	B-Architecture
service	I-Architecture
providers	I-Architecture
often	O
store	O
more	O
than	O
one	O
customer	O
's	O
data	O
on	O
the	O
same	O
server	O
.	O
</s>
<s>
To	O
handle	O
such	O
sensitive	O
situations	O
,	O
cloud	B-Architecture
service	I-Architecture
providers	I-Architecture
should	O
ensure	O
proper	O
data	B-General_Concept
isolation	I-General_Concept
and	O
logical	O
storage	O
segregation	O
.	O
</s>
<s>
The	O
extensive	O
use	O
of	O
virtualization	B-General_Concept
in	O
implementing	O
cloud	O
infrastructure	O
brings	O
unique	O
security	O
concerns	O
for	O
customers	O
or	O
tenants	O
of	O
a	O
public	O
cloud	B-Architecture
service	I-Architecture
.	O
</s>
<s>
Virtualization	B-General_Concept
alters	O
the	O
relationship	O
between	O
the	O
OS	O
and	O
underlying	O
hardware	B-Architecture
–	O
be	O
it	O
computing	O
,	O
storage	O
or	O
even	O
networking	O
.	O
</s>
<s>
This	O
introduces	O
an	O
additional	O
layer	O
–	O
virtualization	B-General_Concept
–	O
that	O
itself	O
must	O
be	O
properly	O
configured	O
,	O
managed	O
and	O
secured	O
.	O
</s>
<s>
Specific	O
concerns	O
include	O
the	O
potential	O
to	O
compromise	O
the	O
virtualization	B-General_Concept
software	O
,	O
or	O
"	O
hypervisor	B-Operating_System
"	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
breach	O
in	O
the	O
administrator	O
workstation	O
with	O
the	O
management	O
software	O
of	O
the	O
virtualization	B-General_Concept
software	O
can	O
cause	O
the	O
whole	O
data	B-Operating_System
center	I-Operating_System
to	O
go	O
down	O
or	O
be	O
reconfigured	O
to	O
an	O
attacker	O
's	O
liking	O
.	O
</s>
<s>
Cloud	B-General_Concept
security	I-General_Concept
architecture	O
is	O
effective	O
only	O
if	O
the	O
correct	O
defensive	O
implementations	O
are	O
in	O
place	O
.	O
</s>
<s>
An	O
efficient	O
cloud	B-General_Concept
security	I-General_Concept
architecture	O
should	O
recognize	O
the	O
issues	O
that	O
will	O
arise	O
with	O
security	O
management	O
and	O
follow	O
all	O
of	O
the	O
best	O
practices	O
,	O
procedures	O
,	O
and	O
guidelines	O
to	O
ensure	O
a	O
secure	O
cloud	O
environment	O
.	O
</s>
<s>
While	O
there	O
are	O
many	O
types	O
of	O
controls	O
behind	O
a	O
cloud	B-General_Concept
security	I-General_Concept
architecture	O
,	O
they	O
can	O
usually	O
be	O
found	O
in	O
one	O
of	O
the	O
following	O
categories	O
:	O
</s>
<s>
This	O
could	O
be	O
achieved	O
by	O
either	O
adding	O
software	O
or	O
feature	O
implementations	O
(	O
such	O
as	O
firewall	O
protection	O
,	O
endpoint	O
protection	O
,	O
and	O
multi-factor	O
authentication	O
)	O
,	O
or	O
removing	O
unneeded	O
functionalities	O
so	O
that	O
the	O
attack	O
surface	O
is	O
minimized	O
(	O
as	O
in	O
unikernel	B-Operating_System
applications	O
)	O
.	O
</s>
<s>
Strong	O
authentication	O
of	O
cloud	B-Architecture
users	I-Architecture
,	O
for	O
instance	O
,	O
makes	O
it	O
less	O
likely	O
that	O
unauthorized	O
users	O
can	O
access	O
cloud	O
systems	O
,	O
and	O
more	O
likely	O
that	O
cloud	B-Architecture
users	I-Architecture
are	O
positively	O
identified	O
.	O
</s>
<s>
Cloud	B-General_Concept
security	I-General_Concept
engineering	O
is	O
characterized	O
by	O
the	O
security	O
layers	O
,	O
plan	O
,	O
design	O
,	O
programming	O
,	O
and	O
best	O
practices	O
that	O
exist	O
inside	O
a	O
cloud	B-General_Concept
security	I-General_Concept
arrangement	O
.	O
</s>
<s>
Cloud	B-General_Concept
security	I-General_Concept
engineering	O
requires	O
the	O
composed	O
and	O
visual	O
model	O
(	O
design	O
and	O
UI	O
)	O
to	O
be	O
characterized	O
by	O
the	O
tasks	O
inside	O
the	O
Cloud	O
.	O
</s>
<s>
This	O
cloud	B-General_Concept
security	I-General_Concept
engineering	O
process	O
includes	O
such	O
things	O
as	O
access	O
to	O
the	O
executives	O
,	O
techniques	O
,	O
and	O
controls	O
to	O
ensure	O
applications	O
and	O
information	O
.	O
</s>
<s>
These	O
interests	O
may	O
include	O
investments	O
in	O
cloud	B-Architecture
computing	I-Architecture
and	O
security	O
,	O
for	O
example	O
.	O
</s>
<s>
Though	O
the	O
idea	O
of	O
cloud	B-Architecture
computing	I-Architecture
is	O
n't	O
new	O
,	O
associations	O
are	O
increasingly	O
enforcing	O
it	O
because	O
of	O
its	O
flexible	O
scalability	O
,	O
relative	O
trustability	O
,	O
and	O
cost	O
frugality	O
of	O
services	O
.	O
</s>
<s>
Cloud	B-General_Concept
security	I-General_Concept
concerns	O
can	O
be	O
grouped	O
in	O
various	O
ways	O
;	O
Gartner	O
named	O
seven	O
while	O
the	O
Cloud	B-General_Concept
Security	I-General_Concept
Alliance	O
identified	O
twelve	O
areas	O
of	O
concern	O
.	O
</s>
<s>
Cloud	B-Application
access	I-Application
security	I-Application
brokers	I-Application
(	O
CASBs	O
)	O
are	O
software	O
that	O
sits	O
between	O
cloud	B-Architecture
users	I-Architecture
and	O
cloud	B-Architecture
applications	I-Architecture
to	O
provide	O
visibility	O
into	O
cloud	B-Architecture
application	I-Architecture
usage	O
,	O
data	O
protection	O
and	O
governance	O
to	O
monitor	O
all	O
activity	O
and	O
enforce	O
security	O
policies	O
.	O
</s>
<s>
Virtual	O
servers	O
should	O
be	O
protected	O
just	O
like	O
a	O
physical	O
server	O
against	O
data	B-Application
leakage	I-Application
,	O
malware	O
,	O
and	O
exploited	O
vulnerabilities	O
.	O
</s>
<s>
CloudID	O
,	O
for	O
instance	O
,	O
provides	O
privacy-preserving	O
cloud-based	B-Architecture
and	O
cross-enterprise	O
biometric	O
identification	O
.	O
</s>
<s>
Cloud	B-Architecture
service	I-Architecture
providers	I-Architecture
physically	O
secure	O
the	O
IT	O
hardware	B-Architecture
(	O
servers	O
,	O
routers	O
,	O
cables	O
etc	O
.	O
)	O
</s>
<s>
This	O
is	O
normally	O
achieved	O
by	O
serving	O
cloud	B-Architecture
applications	I-Architecture
from	O
professionally	O
specified	O
,	O
designed	O
,	O
constructed	O
,	O
managed	O
,	O
monitored	O
and	O
maintained	O
data	B-Operating_System
centers	I-Operating_System
.	O
</s>
<s>
Various	O
information	O
security	O
concerns	O
relating	O
to	O
the	O
IT	O
and	O
other	O
professionals	O
associated	O
with	O
cloud	B-Architecture
services	I-Architecture
are	O
typically	O
handled	O
through	O
pre-	O
,	O
para	O
-	O
and	O
post-employment	O
activities	O
such	O
as	O
security	O
screening	O
potential	O
recruits	O
,	O
security	O
awareness	O
and	O
training	O
programs	O
,	O
and	O
proactive	O
.	O
</s>
<s>
Providers	O
ensure	O
that	O
all	O
critical	O
data	O
(	O
credit	O
card	O
numbers	O
,	O
for	O
example	O
)	O
are	O
masked	B-General_Concept
or	O
encrypted	O
and	O
that	O
only	O
authorized	O
users	O
have	O
access	O
to	O
data	O
in	O
its	O
entirety	O
.	O
</s>
<s>
Moreover	O
,	O
digital	O
identities	O
and	O
credentials	O
must	O
be	O
protected	O
as	O
should	O
any	O
data	O
that	O
the	O
provider	O
collects	O
or	O
produces	O
about	O
customer	O
activity	O
in	B-Architecture
the	I-Architecture
cloud	I-Architecture
.	O
</s>
<s>
Penetration	O
testing	O
is	O
the	O
process	O
of	O
performing	O
offensive	O
security	O
tests	O
on	O
a	O
system	O
,	O
service	O
,	O
or	O
computer	B-Architecture
network	I-Architecture
to	O
find	O
security	O
weaknesses	O
in	O
it	O
.	O
</s>
<s>
Virtual	O
servers	O
should	O
be	O
hardened	O
just	O
like	O
a	O
physical	O
server	O
against	O
data	B-Application
leakage	I-Application
,	O
malware	O
,	O
and	O
exploited	O
vulnerabilities	O
.	O
</s>
<s>
Traditional	O
threats	O
include	O
:	O
network	B-Protocol
eavesdropping	I-Protocol
,	O
illegal	O
invasion	O
,	O
and	O
denial	O
of	O
service	O
attacks	O
,	O
but	O
also	O
specific	O
cloud	B-Architecture
computing	I-Architecture
threats	O
,	O
such	O
as	O
side	O
channel	O
attacks	O
,	O
virtualization	B-General_Concept
vulnerabilities	O
,	O
and	O
abuse	O
of	O
cloud	B-Architecture
services	I-Architecture
.	O
</s>
<s>
Meanwhile	O
,	O
data	O
owners	O
expect	O
to	O
fully	O
utilize	O
cloud	O
data	O
services	O
,	O
e.g.	O
,	O
data	O
search	O
,	O
data	O
computation	O
,	O
and	O
data	B-Application
sharing	I-Application
,	O
without	O
the	O
leakage	O
of	O
the	O
data	O
contents	O
to	O
CSPs	O
or	O
other	O
adversaries	O
.	O
</s>
<s>
Symmetric	O
or	O
asymmetric	B-Application
key	I-Application
paradigm	O
can	O
be	O
used	O
for	O
encryption	O
.	O
</s>
<s>
While	O
cloud	B-Architecture
computing	I-Architecture
is	O
on	O
the	O
cutting	O
edge	O
of	O
information	O
technology	O
there	O
are	O
risks	O
and	O
vulnerabilities	O
to	O
consider	O
before	O
investing	O
fully	O
in	O
it	O
.	O
</s>
<s>
Cloud	B-Architecture
computing	I-Architecture
is	O
still	O
an	O
emerging	O
technology	O
and	O
thus	O
is	O
developing	O
in	O
relatively	O
new	O
technological	O
structures	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
all	O
cloud	B-Architecture
services	I-Architecture
must	O
undertake	O
Privacy	O
Impact	O
Assessments	O
or	O
PIAs	O
before	O
releasing	O
their	O
platform	O
.	O
</s>
<s>
There	O
are	O
several	O
different	O
types	O
of	O
attacks	O
on	O
cloud	B-Architecture
computing	I-Architecture
,	O
one	O
that	O
is	O
still	O
very	O
much	O
untapped	O
is	O
infrastructure	O
compromise	O
.	O
</s>
<s>
Since	O
cloud	B-Architecture
computing	I-Architecture
software	O
is	O
used	O
by	O
large	O
numbers	O
of	O
people	O
,	O
resolving	O
these	O
attacks	O
is	O
increasingly	O
difficult	O
.	O
</s>
<s>
Now	O
with	O
cloud	B-Architecture
computing	I-Architecture
on	O
the	O
rise	O
,	O
this	O
has	O
left	O
new	O
opportunities	O
for	O
attacks	O
because	O
of	O
the	O
virtualization	B-General_Concept
of	O
data	B-Operating_System
centers	I-Operating_System
and	O
cloud	B-Architecture
services	I-Architecture
being	O
utilized	O
more	O
.	O
</s>
<s>
Some	O
advanced	O
encryption	O
algorithms	O
which	O
have	O
been	O
applied	O
to	O
cloud	B-Architecture
computing	I-Architecture
increase	O
the	O
protection	O
of	O
privacy	O
.	O
</s>
<s>
Attribute-based	O
encryption	O
is	O
a	O
type	O
of	O
public-key	B-Application
encryption	I-Application
in	O
which	O
the	O
secret	O
key	O
of	O
a	O
user	O
and	O
the	O
ciphertext	O
are	O
dependent	O
upon	O
attributes	O
(	O
e.g.	O
</s>
<s>
Some	O
of	O
the	O
strengths	O
of	O
Attribute-based	O
encryption	O
are	O
that	O
it	O
attempts	O
to	O
solve	O
issues	O
that	O
exist	O
in	O
current	O
public-key	B-Application
infrastructure(PKI )	O
and	O
identity-based	O
encryption(IBE )	O
implementations	O
.	O
</s>
<s>
Ciphertext-policy	O
ABE	O
(	O
CP-ABE	O
)	O
is	O
a	O
type	O
of	O
public-key	B-Application
encryption	I-Application
.	O
</s>
<s>
The	O
KeyGen	O
algorithm	O
then	O
takes	O
the	O
master	O
key	O
and	O
the	O
user	O
's	O
attributes	O
to	O
develop	O
a	O
private	B-Application
key	I-Application
.	O
</s>
<s>
Finally	O
,	O
the	O
Decrypt	O
algorithm	O
takes	O
the	O
public	O
parameters	O
,	O
the	O
ciphertext	O
,	O
the	O
private	B-Application
key	I-Application
,	O
and	O
user	O
attributes	O
as	O
input	O
.	O
</s>
<s>
In	O
a	O
KP-ABE	O
system	O
,	O
ciphertexts	O
,	O
or	O
the	O
encrypted	O
messages	O
,	O
are	O
tagged	O
by	O
the	O
creators	O
with	O
a	O
set	O
of	O
attributes	O
,	O
while	O
the	O
user	O
's	O
private	B-Application
keys	I-Application
are	O
issued	O
that	O
specify	O
which	O
type	O
of	O
ciphertexts	O
the	O
key	O
can	O
decrypt	O
.	O
</s>
<s>
The	O
private	B-Application
keys	I-Application
control	O
which	O
ciphertexts	O
a	O
user	O
is	O
able	O
to	O
decrypt	O
.	O
</s>
<s>
In	O
KP-ABE	O
,	O
the	O
attribute	O
sets	O
are	O
used	O
to	O
describe	O
the	O
encrypted	O
texts	O
and	O
the	O
private	B-Application
keys	I-Application
are	O
associated	O
to	O
the	O
specified	O
policy	O
that	O
users	O
will	O
have	O
for	O
the	O
decryption	O
of	O
the	O
ciphertexts	O
.	O
</s>
<s>
FHE	O
has	O
been	O
linked	O
not	O
only	O
to	O
cloud	B-Architecture
computing	I-Architecture
but	O
to	O
electronic	O
voting	O
as	O
well	O
.	O
</s>
<s>
Fully	O
Homomorphic	O
Encryption	O
has	O
been	O
especially	O
helpful	O
with	O
the	O
development	O
of	O
cloud	B-Architecture
computing	I-Architecture
and	O
computing	O
technologies	O
.	O
</s>
<s>
However	O
,	O
as	O
these	O
systems	O
are	O
developing	O
the	O
need	O
for	O
cloud	B-General_Concept
security	I-General_Concept
has	O
also	O
increased	O
.	O
</s>
<s>
FHE	O
aims	O
to	O
secure	O
data	O
transmission	O
as	O
well	O
as	O
cloud	B-Architecture
computing	I-Architecture
storage	O
with	O
its	O
encryption	O
algorithms	O
.	O
</s>
<s>
SE	O
schemes	O
can	O
be	O
classified	O
into	O
two	O
categories	O
:	O
SE	O
based	O
on	O
secret-key	B-Application
(	O
or	O
symmetric-key	O
)	O
cryptography	O
,	O
and	O
SE	O
based	O
on	O
public-key	B-Application
cryptography	I-Application
.	O
</s>
<s>
Singapore	O
's	O
Multi-Tier	O
Cloud	B-General_Concept
Security	I-General_Concept
Standard	O
.	O
</s>
<s>
Cloud	B-Architecture
service	I-Architecture
users	O
may	O
often	O
need	O
to	O
be	O
aware	O
of	O
the	O
legal	O
and	O
regulatory	O
differences	O
between	O
the	O
jurisdictions	O
.	O
</s>
<s>
For	O
example	O
,	O
data	O
stored	O
by	O
a	O
cloud	B-Architecture
service	I-Architecture
provider	I-Architecture
may	O
be	O
located	O
in	O
,	O
say	O
,	O
Singapore	O
and	O
mirrored	O
in	O
the	O
US	O
.	O
</s>
<s>
Cloud	O
providers	O
have	O
business	O
continuity	O
and	O
data	B-Application
recovery	I-Application
plans	O
in	O
place	O
to	O
ensure	O
that	O
service	O
can	O
be	O
maintained	O
in	O
case	O
of	O
a	O
disaster	O
or	O
an	O
emergency	O
and	O
that	O
any	O
data	O
loss	O
will	O
be	O
recovered	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
requirements	O
to	O
which	O
customers	O
are	O
subject	O
,	O
the	O
data	B-Operating_System
centers	I-Operating_System
used	O
by	O
cloud	O
providers	O
may	O
also	O
be	O
subject	O
to	O
compliance	O
requirements	O
.	O
</s>
<s>
Using	O
a	O
cloud	B-Architecture
service	I-Architecture
provider	I-Architecture
(	O
CSP	O
)	O
can	O
lead	O
to	O
additional	O
security	O
concerns	O
around	O
data	O
jurisdiction	O
since	O
customer	O
or	O
tenant	O
data	O
may	O
not	O
remain	O
on	O
the	O
same	O
system	O
,	O
in	O
the	O
same	O
data	B-Operating_System
center	I-Operating_System
,	O
or	O
even	O
within	O
the	O
same	O
provider	O
's	O
cloud	O
.	O
</s>
<s>
Public	O
agencies	O
using	O
cloud	B-Architecture
computing	I-Architecture
and	O
storage	O
must	O
take	O
these	O
concerns	O
into	O
account	O
.	O
</s>
