Optik
125 (2014) 1361–
1365
Contents
lists
available
at
ScienceDirect
Optik
jou
rn
al
homepage:
www.elsevier.de/ijleo
A
novel
encryption
scheme
based
on
timestamp
in
gigabit
Ethernet
passive
optical
network
using
AES-128
Aihan
Yin
∗
,
Shengkai
Wang
School
of
Information
Engineering,
East
China
Jiaotong
University,
Nanchang
330013,
China
a
r
t
i
c
l
e
i
n
f
o
Article
history:
Received
10
April
2013
Accepted
15
August
2013
Keywords:
GEPON
Timestamp
AES-128
Encryption
Key
expansion
a
b
s
t
r
a
c
t
Recently,
Li
et
al.
proposed
an
encryption
scheme
in
gigabit
Ethernet
passive
optical
network
(GEPON)
based
on
timestamp.
We
have
shown
that
Li’s
encryption
scheme
is
not
advisable,
since
it
cannot
decrypt.
In
this
paper,
we
proposed
a
novel
encryption
scheme
based
on
timestamp
in
GEPON
using
AES-128,
aiming
at
solving
the
security
problem
of
a
transmission
in
downstream
of
GEPON.
In
this
scheme,
the
keys
formed
by
combining
AES-128
algorithm
with
timestamp
in
the
process
of
key
expansion
are
used
for
encrypting
the
downstream
data.
Furthermore,
accompanying
the
dynamic
update
and
synchronization
of
keys,
the
extraction
and
synchronization
of
timestamp
are
released.
Then,
the
timestamp
used
in
ONUs’
ranging
to
generate
time-related
keys
and
realize
the
secure
update
and
synchronization
of
keys.
The
simulation
results
indicate
that
this
scheme
is
more
suitable
for
GEPON
to
solve
the
potential
safety
threats
than
other
traditional
algorithms.
© 2013 Elsevier GmbH. All rights reserved.
1.
Introduction
EPON,
as
a
typical
optical
access
network,
has
many
advantages
such
as
high
speed,
simple
topology
and
favorable
compatibility
with
Ethernet.
Therefore,
it
has
gained
support
from
the
equip-
ment
manufacturers
and
has
been
widely
deployed.
However,
the
telecommunications
operators
are
not
so
interesting
in
it
for
the
inevitable
security
threats
caused
by
its
topology,
such
as
eaves-
dropping
and
masquerading
[1,2].
What
is
even
worse
is
these
threats
are
still
unsolved
in
the
next
generation
GEPON
[3].
The
topology
of
GEPON
is
simple
point-to-multi-point
(P2MP)
structure.
All
downstreams
are
broadcast
to
ONUs
by
OLT.
With
the
help
of
the
logical
link
identifier
(LLID)
filtering
rule,
ONU
could
extract
its
own
data
and
discard
the
data
belonging
to
other
ONUs
[4].
Nevertheless,
malicious
user
could
easily
obtain
all
the
data
flow
without
restriction
by
simply
abandoning
the
LLID
filter-
ing
rule.
What
makes
the
situation
worse,
in
this
case,
is
that
the
eavesdropping
is
completely
passive
and
undetectable
[5].
After
collecting
enough
identity
related
information,
malicious
user
can
pretend
to
be
a
legal
user
to
join
the
network
and
launch
attack.
Thus,
the
encryption
for
traffic
in
GEPON
is
needed
to
avoid
being
monitored
[6].
In
recent
years,
several
precepts
have
been
proposed
to
encrypt
the
downstream
data
to
solve
the
secure
problems
in
GEPON.
Pedro
et
al.
[7]
,
in
2006,
proposed
encrypting
the
preamble
of
data
units;
Marek
et
al.
[8],
in
2007,
proposed
a
scheme
combining
advanced
∗
Corresponding
author.
E-mail
address:
ecjtu5102@126.com
(A.
Yin).
encryption
standard
(AES)
with
Rivest–Shamir–Adleman
(RSA);
Cheng
et
al.
[9],
in
2007,
proposed
encrypting
the
downstream
data
only
with
triple
churning
algorithm;
Aihan
et
al.
[10],
in
2010,
pro-
posed
a
scheme
combining
advanced
encryption
standard
(AES)
with
elliptic
curve
cryptography
(ECC);
Sarwarul
et
al.
[11],
in
2010,
proposed
encrypting
the
downstream
data
only
with
advanced
encryption
standard
counter
mode
(AES-CTR).
However,
all
solutions
mentioned
above
cannot
satisfy
the
requirement
of
secure
and
real-time
multiservice.
Also
there
are
potential
safety
threats
during
the
transmission
of
keys.
In
order
to
solve
the
problem,
Li
et
al.
[12]
proposed
a
scheme
by
combining
AES
algorithm
with
timestamp
in
the
process
of
MixColumns
shift
to
encrypt
the
downstream
data.
In
this
paper
we
have
shown
that
Li’s
encryption
scheme
could
not
be
achieved,
since
it
is
impossible
to
reverse
the
data
after
the
timestamp
combines
with
AES
in
the
process
of
MixColumns
shift.
To
solve
the
problem
in
GEPON
any
further,
a
novel
encryption
scheme
is
proposed.
The
rest
of
the
paper
is
organized
as
follows.
Section
2
describes
the
necessary
technical
backgrounds
of
the
proposed
work.
In
Sec-
tion
3,
Li
et
al.’s
scheme
is
revisited
and
inaccuracy
of
it
is
introduced
in
Section
4.
Section
5
expounds
the
proposed
scheme
and
the
secu-
rity
and
performance
analysis
of
the
proposed
scheme
are
given
in
Section
6.
The
concluding
remarks
are
provided
in
Section
7.
2.
Preliminaries
In
this
section,
we
first
introduce
the
basic
concept
of
AES
and
the
round
trip
time
(RTT)
of
ranging
in
GEPON,
and
the
inverse
of
the
polynomial
is
also
given.
0030-4026/$
–
see
front
matter ©
2013 Elsevier GmbH. All rights reserved.
http://dx.doi.org/10.1016/j.ijleo.2013.08.030