Wireless Network Security Still Has no Clothes.

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112 International Arab Journal of e-Technology, Vol. 2, No. 2, June 2011
Wireless Network Security Still Has no Clothes
Diaa Salama1, Hatem Abdual Kader2, and Mohiy Hadhoud2
1Jazan University , Kingdom of Saudi Arabia
2Minufiya University, Egypt
Abstract:As the popularity of wireless networks increases, so does the need to protect them. Encryption algorithms play a
main role in information security systems. On the other side, those algorithms consume a significant amount of computing
resources such as CPU time, memory, and battery power. This paper illustrates the key concepts of security, wireless
networks, and security over wireless networks. Wireless security is demonstrated by applying the common security standards
like (802.11 WEP and 802.11i WPA,WPA2) and provides evaluation of six of the most common encryption algorithms on
power consumption for wireless devices namely: AES (Rijndael), DES, 3DES, RC2, Blowfish, and RC6. A comparison has
been conducted for those encryption algorithms at different settings for each algorithm such as different sizes of data blocks,
different data types, battery power consumption, date transmission through wireless network and finally encryption/decryption
speed. Experimental results are given to demonstrate the effectiveness of each algorithm.
Keywords: Encryption techniques, Computer security, wireless network, ad hoc wireless LANs, Basic Service Set (BBS)
Received November 25, 2009; Accepted September 19, 2010
1. Introduction
Data Security was found many years before the
beginning of wireless communication. Both security
and wireless communication will remain an interesting
subject for years to come. Wireless networks fall into
several categories, depending on the size of the
physical area that they are capable of covering. The
following types of wireless networks satisfy different
user requirements: Wireless Personal-Area Network
(PAN), Wireless Local-Area Network (LAN), Wireless
Metropolitan-Area Network (MAN) and Wireless
Wide Area Network (WAN).
Many encryption algorithms are widely available and
used in information security. They can be categorized
into Symmetric (private) and Asymmetric (public)
keys encryption. In Symmetric keys encryption or
secret key encryption, only one key is used to encrypt
and decrypt data. DES uses one 64-bits key. Triple
DES (3DES) uses three 64-bits keys [6, 12, 23, 27]
while AES uses various (128,192,256) bits keys [7,
20]. Blowfish uses various (32-448); default 128bits
[7] while RC6 is used various (128,192,256) bits keys
[8].
In Asymmetric keys encryption, two keys are used;
private and public keys. Public key is used for
encryption and private key is used for decryption (E.g.
RSA and ECC). Public key encryption is based on
mathematical functions, computationally intensive and
is not very efficient for small mobile devices [12, 23].
Strength of Symmetric key encryption depends on the
size of key used. There are many examples of strong
and weak keys of cryptography algorithms like RC2,
DES, 3DES, RC6, Blowfish, and AES. RC2 uses one
64-bit key .DES
This paper examines a method for evaluating
performance of selected symmetric encryption of
various algorithms on power consumption for wireless
devices. A wireless device is limited in resources such
as less memory, less processing power and limited
power supply (battery). Battery power is subjected to
the problem of energy consumption due to encryption
algorithms. Battery technology is increasing at a
slower rate than other technologies. This causes a
“battery gap” [17, 19, 5].We need a way to make
decisions about energy consumption and security to
reduce the consumption of battery powered devices.
This study evaluates six different encryption
algorithms used or suggested for wireless local area
network (WLANs) namely; AES, DES, 3DES, RC6,
Blowfish, and RC2. The performance measure of
encryption schemes will be conducted in terms of
energy for wireless devices, changing data types -such
as text or document, and Video files on power
consumption, changing packet size for the selected
cryptographic algorithms on wireless devices.
This paper is organized as follows. A wireless
network overview is explained in section 2.Related
work is described in Section 3. A view of experimental
design is given in section 4. Experimental results are
shown in section 5. Finally the conclusions are drawn
section 6.
2. Wireless Overview
The primary difference between wireless and wired
networks lies in the communications medium. Wired
networks utilize cabling to transfer electrical current
that represents information. With wireless networks,

Wireless Network Security Still Has no Clothes 113
radio frequency (RF) and light signals have the job of carrying information invisibly through the air.
2.1. Wireless LANs
Wireless LANs supply high performance within and
around office buildings, factories, and homes[4]. Table
1 provides some key characteristics at a glance.
Table 1. Key Characteristics of 802.11 Wireless LANs.
Characteristic
Description
Physical Layer
Direct Sequence Spread Spectrum (DSSS),
Frequency Hopping Spread Spectrum (FHSS),
Orthogonal Frequency Division Multiplexing
(OFDM), infrared (IR).
Frequency Band
2.4 GHz (ISM band) and 5 GHz.
Data Rates
1 Mbps, 2 Mbps, 5.5 Mbps (11b), 11 Mbps
(11b), 54 Mbps (11a)
Data &Network
Security
RC4-based stream encryption algorithm for
confidentiality, authentication, and integrity.
Limited key management. (AES is being
considered for IEEE 802.11i.)
Operating Range
Up to 150 feet indoors and 1500 feet
outdoors.9
Negative
Aspects
Poor security in native mode; throughput
decrease with distance and load.
Wireless LANs consist mainly of two entities:
clients or end-user devices and Access Points. The
basic structure of a Wireless LAN is called
infrastructure WLAN or BSS (Basic Service Set)
shown infigure 1, in which the network consists of an
access point and several wireless devices. When these
devices try to communicate among themselves they
propagate their data through the access point device.
Figure 1. Wireless LANs (BBS structure).
If the BSS did not have an access point device, and
the wireless devices were communicating with each
other directly, this BSS is called an Independent BSS
and works in mode called "ad hoc mode" (shown in
figure2). Ad hoc networks are also commonly referred
to as peer-to-peer networks [1].
Figure. 2. Ad hoc Wireless LANs.
The two architectures of wireless LAN is applied in
our experiment
2.1.1. Security in WLANs (IEEE 802.11 Standards)
The IEEE 802.11 standard specifies a common
medium access control (MAC) and several physical
layers for wireless LANs. The 802.11 IEEE standards
were standardized in 1997. It consists of three layers:
Physical layer, MAC (Medium Access Control) layer,
and LLC (Logical Link Control) layer.
To allow clients to access the network they must be go
through two steps: getting authenticated by the access
point, then getting associated. There are two types of
authentications used in IEEE 802.11 standard: Shared
Key Authentication and Open System Authentication
[18].
Open system authentication is mandatory (Figure 3),
and it's a two-step process. A radio NIC initiates the
process by sending an authentication request frame to
the access point. The access point replies with an
authentication response frame containing approval or
disapproval of authentication indicated in the status
code field in the frame body [15].
Figure 3. Open System authentication.
Shared key authentication is an optional four-step
process that bases authentication on whether the
authenticating device has the correct WEP key. The
radio NIC starts by sending an authentication request
frame to the access point. The access point then places
challenge text into the frame body of a response frame
and sends it to the radio NIC. The radio NIC uses its
WEP key to encrypt the challenge text and then sends
it back to the access point in another authentication
frame. The access point decrypts the challenge text and
compares it to the initial text. If the text is equivalent,
the access point assumes that the radio NIC has the
correct key. The access point finishes the sequence by
sending an authentication frame to the radio NIC with
the approval or disapproval. Figure4 shows how
Shared Key Authentication works.

114 International Arab Journal of e-Technology, Vol. 2, No. 2, June 2011
Figure 4. Shared Key Authentication.
2.1.2. Data Encryption and Authentication Protocol
The first data encryption and authentication protocol
used in WLANs was called Wired Equivalent Privacy
(WEP). WEP doesn't provide enough security for most
enterprise wireless LAN applications. Because of static
key usage, it's fairly easy to crack WEP with off-the-
shelf tools [16, 24]. Wireless Fidelity (Wi-Fi) alliance,
released a new Security protocol standard in 2002, and
called Wi-Fi Protected Access (WPA), which aims to
fix the flaws [9]. A year later, another version of the
WPA standard, WPA version 2 (WPA2) [10], was
released to provide advanced security services. The
802.11i standard provides two data encryption services
called Temporal Key Integrity Protocol (TKIP) and
Counter Mode (CTR) Encryption with AES Cipher
(CTR-AES), and two data authentication services
called Michael and Cipher Block Chaining Message
Authentication Code (CBC-MAC) [25]. The WPA
standard is composed of the use of TKIP and Michael
together to provide data encryption and authentication
services while WPA2 is composed of CTR-AES and
CBC-MAC. Together with CBC-MAC and CTR-AES,
it is called CCMP (Counter Mode CBC-MAC
Protocol).
802.11i specifies three protocols: TKIP, CCMP and
WRAP. TKIP (Temporal Key Integrity Management)
was introduced as a "band-aid" solution to WEP
problems. One of the major advantages of
implementing TKIP is that you do not need to update
the hardware of the devices to run it. Unlike WEP,
TKIP provides per-packet key mixing, a message
integrity check and a re-keying mechanism. TKIP
ensures that every data packet is sent with its own
unique encryption key. TKIP is included in 802.11i
mainly for backward compatibility. WRAP (Wireless
Robust Authenticated Protocol) is the LAN
implementation of the AES encryption standard
introduced earlier. It was ported to wireless to get the
benefits of AES encryption. WRAP has academic
property issues [2]. CCMP (Counter with Cipher Block
Chaining Message Authentication Code Protocol) is
considered the optimal solution for secure data transfer
under 802.11i. CCMP uses AES for encryption. The
use of AES will require a hardware upgrade to support
the new encryption algorithm. HiperLAN/2 is a
European-based standard that is unlikely to compete
heavily with 802.11.
3. Related Work
To give more prospective about the performance of the
compared algorithms, this section discusses the results
obtained from other resources.
It was shown in [23] that energy consumption of
different common symmetric key encryptions on
handheld devices. It is found that after only 600
encryptions of a 5 MB file using Triple-DES the
remaining battery power is 45% and subsequent
encryptions are not possible as the battery dies rapidly.
It was concluded in [13] that AES is faster and more
efficient than other encryption algorithms. When the
transmission of data is considered there is insignificant
difference in performance of different symmetric key
schemes. Increasing the key size by 64 bits of AES
leads to increase in energy consumption about 8%
without any data transfer. The difference is not
noticeable.
A study in [22] is conducted for different secret key
algorithms such as DES, 3DES, AES, and Blowfish.
They were implemented, and their performance was
compared by encrypting input files of varying contents
and sizes. The algorithms were tested on two different
hardware platforms, to compare their performance.
They had conducted it on two different machines: P-II
266 MHz and P-4 2.4 GHz. The results showed that
Blowfish had a very good performance compared to
other algorithms. Also it showed that AES had a better
performance than 3DES and DES. It also shows that
3DES has almost 1/3 throughput of DES, or in other
words it needs 3 times than DES to process the same
amount of data.
In [14] a study of security measure level has been
proposed for a web programming language to analyze
four Web browsers. This study consider of measuring
the performances of encryption process at the
programming language’s script with the Web
browsers. This is followed by conducting tests
simulation in order to obtain the best encryption
algorithm versus Web browser.
A study in [11] is conducted for different popular
secret key algorithms such as RC4, AES, and XOR.
They were implemented, and their performance was
compared by encrypting for real time video streaming
of varying contents. The results showed; encryption
delay overhead using AES is less than the overhead
using RC4 and XOR algorithm. Therefore, AES is a
feasible solution to secure real time video
transmissions.

Wireless Network Security Still Has no Clothes 115
4. Experimental Design
The setup for the proposed experiment is shown in figure
2.Two laptops are used in the experiment. The two
laptops (sender and receiver) had windows XP
professional installed on it. The first laptop (sender) is
connected to access point.
Figure 5. Configuration of the Experiment setup.
In the experiments, the first laptop encrypts a
different file size for different data types ranges from
321 Kilobytes to 7.139Megabytes for text data (.DOC
files), from 33 Kbytes to 8,262 Kbytes for audio data
(.WAV files), from 28 Kbytes to 131 Kbytes for
pictures and Images (.GIF and GPG files) using .NET
environment. Six encryption algorithm that are
selected in the experiment are AES (key size:256
bits),DES(key size:64 bits),RC2(key size:64
bits),RC6(key size:256 bits),Blowfish(key size:256
bits),and 3DES(key size:192 bits) . These
implementations are thoroughly tested and are
optimized to give the maximum performance for each
algorithm. The results are checked and tested for AES
that supposed to be the best encryption algorithms by a
different implementations program to give the
maximum performance for the algorithms and make
sure the results are the same using multiple platforms.
Then for transmission of data, the two laptops are
connected wirelessly. Data is transmitted from the first
laptop to the second one through the wireless link
using TCP/IP protocol. the experiment are applied in
two mode of wireless LANs connection (BSS and ad
hoc mode).Using IEEE 802.11 standard, data is
transmitted using the two different types of
authentication. First, data is transmitted using Open
System Authentication (no encryption). Second case,
data is transmitted using Shared Key Authentication
(WEP encryption). Using IEEE 802.11i, data is
transmitted using Open System Authentication (no
encryption) and data is transmitted using WPA. The
effects of different signal to noise conditions and its
effect on transmission of data (under excellent signals
and poor signals) are studied. Several performance
metrics are measured:
•Encryption time.
•Throughput.
•Battery power.
•Transmission time in many cases.
The encryption time is considered the time that an
encryption algorithm takes to produce a cipher text
from a plaintext. Encryption time is used to calculate
the throughput of an encryption scheme. It indicates
the speed of encryption.
The throughput of the encryption scheme is calculated
as in equation (1).
Throughput of encryption =
)( )(
SecondEt BytesTp
where Tp: total plain text (bytes)
Et: encryption time (second)
The CPU process time is the time that a CPU is
committed only to the particular process of
calculations. It reflects the load of the CPU.
The CPU clock cycles are a metric, reflecting the
energy consumption of the CPU while operating on
encryption operations. Each cycle of CPU will
consume a small amount of energy.
The road map for experiment steps are explained in
sections 4.1., 4.2. and 4.3.
4.1. Results Comparison
A comparison is conducted between the results of
selected different encryption algorithms using different
setting such as different and data types, different
packet size, different key size
•In case of changing packet size, (throughput, power
consumption in µJoule/Byte and power
consumption by calculating difference in battery
percentage were calculated) in case of encryption
processes to calculate the performance of each
encryption algorithms.
•In case of changing data types such as audio, ,(
throughput ,power consumption in µJoule/Byte and
power consumption by calculating difference in
battery percentage were calculated)in case of
encryption processes to calculate the performance
of each encryption algorithms.
These results lead to second step in section 4.2.
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116 International Arab Journal of e-Technology, Vol. 2, No. 2, June 2011
4.2. Calculating With Data Transmission
A comparison is conducted between the results in case
of data transmission using BSS and ah hoc wireless
network. The main difference between BSS mode and
Ad-hoc mode that Ad-hoc mode hasn't access point
between sender and receiver
4.2.1. Ad-Hoc Structure
In case of Ad-hoc structure with excellent signals
(distance between two laptops less than 4 meters and
there are any application running except data
transmission) and poor signals (distance between two
laptops is greater than 50 meters contains walls in the
distance between two laptops).
•In case excellent signals, comparison is conducted
using two different types of authentication (Open
Key Authentication (no encryption), and Shared
Key Authentication (WEP)).For each type of
authentication, the transmission time, and power
consumption for encryption are calculated for
different packet size and different data types. So
that, the performance for each cryptographic
algorithms in case of data transmission and with out
data transmission for two different type of
authentication in Ad-hoc structure using excellent
signals between sender and receiver can be
calculated.
•In case poor signals, comparison is conducted using
(WEP) .The transmission time and power
consumption of encryption are calculated for
different packet size and different data types. So
that, the performance for each cryptographic
algorithms in case of data transmission and with out
data transmission in Ad-hoc structure using poor
signals between source and destination can be
calculated.
4.2.2. BSS Mode
In case of BSS mode, comparison is conducted with
excellent signal between sender and receiver the
studying the effects of transmitted data using IEEE
802.11i (Open Key Authentication (no encryption),
and WPA/TKIP) by calculating transmission time and
power consumed for transmission between the two
entities for different packet size and different data
types.
The battery and computational trade-off of
encryption schemes under different scenarios are
considered in various experimental setups but the
original setup remains the same.
Processing in experiment for encryption without
data transmission is to read data from the file encrypt
the data and put it in another file. In case of encryption
with data transmission the data is read from the file
encrypted and the send to the second laptop. This is
done till the battery drains to 30% of the lifetime left.
We stop at 30% because after that the systems alarm
and data recovery mechanisms become active and the
performance of the schemes change. After a few runs
of processing on the file the battery life left and the
system time is recorded. The average battery life
consumed per run and the time taken to do so is the
calculated for the results. It is expected that the
computation time would be closely related to the
battery requirements; however, since the CPU
utilization of power depends on parameters like
voltage supply and capacitive load. The capacitive load
on the CPU depends on the switching demand, which
again depends on the instructions being executed.
Hence, measurements for both the parameters are
considered.
4.3. Measurement of Energy Consumption
Energy consumption for encryption and decryption can
be measured in many ways. These methods as follows:
The First method used to measure energy
consumption is to assume that an average amount of
energy is consumed by normal operations and to test
the extra energy consumed by an encryption
algorithms. This method simply monitors the level of
the percentage of remaining battery that can computed
by equations (2) and (3).
The battery life consumed in percentage for one run =
runsofnumberthe lifebatteryinChange
Average battery Consumed per iteration=
N
IterationsumedPerBatteryCon
N
∑
1
The second method of security primitives can also be
measured by counting the amount of computing cycles
which are used in computations related to
cryptographic operations. For computation of the
energy cost of encryption, we use the same techniques
as described in [20, 22] using the following equations.
Bcost_encryption (ampere-cycle) = τ * I
Tenergy_cost (ampere-seconds) =
ec)F(cycles/s cycle)-(ampereB ptioncost_encry
Ecost (Joule) = Tenergy_cost (ampere-seconds)*V
where Bcost_encryption: a basic cost of encryption
(ampere-cycle).
τ: the total number of clock cycles.
I: the average current drawn by each CPU
clock cycle.
(2)
(3)
(4)
(5)
(6)

Wireless Network Security Still Has no Clothes 117
Tenergy_cost: the total energy cost (ampere-
seconds).
F: clock frequency (cycles/sec).
Ecost (Joule): the energy cost (consumed).
By using the cycles, the operating voltage of the CPU,
and the average current drawn for each cycle, we can
calculate the energy consumption of cryptographic
functions. For example, on average, each cycle
consumes approximately 270 mA on an Intel 486DX2
processor [20] or 180 mA on Intel Strong ARM [26].
For a sample calculation, with a 700 MHz CPU
operating at 1.35 Volt, an encryption with 20,000
cycles would consume about 5.71 x 10-3 mA-second
or 7.7 μ Joule.
So, the amount of energy consumed by program P
to achieve its goal (encryption or decryption) is given
by
E= VCC × I × N × τ
Where N: the number of clock cycles.
τ: the clock period.
VCC: the supply voltage of the system
I: the average current in amperes drawn from
the power source for T seconds.
Since for a given hardware, both VCC and τ are fixed,
E α I × N. However, at the application level, it is more
meaningful to talk about T than N, and therefore, we
express energy as E α I × T. Since for a given hardware
Vcc are fixed [22]. The Scand and third methods were
used in this work.
5. Experimental Results
5.1. The Effect of Cryptographic Algorithms on
Power Consumption (Text Files)
5.1.1. Encryption of Different Packet Size
Encryption time is used to calculate the throughput of
an encryption scheme. In this section, Encryption
throughput (Megabytes/Sec) and power consumption
by using two different methods (µJoule/Byte, and
Average battery Consumed per iteration) are calculated
for encrypting text files (.doc files) without
transmission to show which encryption is more
powerful than others. The results are shown in (figure
6, figure 7 and figure 8) respectively.
•Encryption Throughput. Throughput of each
encryption algorithm to encrypt different text data
(Megabytes/Sec) without data transmission is shown
in figure 6.
•Power Consumption (µJoule/Byte). The Power
consumption to encrypt different text data (.doc
files) with a different data block size in micro
joule/bytes are shown in figure 7.
•Power Consumption (Percentage of Battery
Consumed).
The Power consumption by calculating change in
battery left for encryption process for text data (.doc
files) with a different data block size are shown in
figure 8.
Figure 6. Throughput of each encryption algorithm to encrypt
different text data (Megabytes/Sec) without data transmission.
Figure 7. Power consumption (µJoule/Byte) for encrypting
different Text document Files without data transmission.
Figure. 8. Power consumption for encrypting different Text
document Files without data transmission.
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118 International Arab Journal of e-Technology, Vol. 2, No. 2, June 2011
5.1.2. Decryption of Different Packet Size (.doc
files)
•Decryption Throughput: The throughput of each
encryption algorithm to decrypt different text data
(Megabytes/Sec) without data transmission is
calculated. Experimental results for this comparison
point are shown in figure 9.
Figure 9. Throughput of each decryption algorithm (Megabyte/Sec)
for text data without data transmission.
•Power Consumption (µJoule/Byte) .The Power
consumption (µJoule/Byte) for decrypting different
Text document Files without data transmission are
calculated. Experimental results for this comparison
point are shown figure 10.
Figure. 10. Power consumption for Decrypting different Text
document Files in µJoule/Byte without data transmission.
5.1.3. Wireless Environment
The effect of changes when transmission of data is
taken in consideration under different scenario such as
transmission of data by using two different
architectures (BSS, and ad hoc mode) are calculated.
The results are shown in (table 2 and in figure 11).
Table 2. Comparative execution times for transmission of text data
using different encryption algorithms.
Text Data
Data to be transmitted
ad hoc
mod(802.11standard)
BBS mod
Excellent
signals
Poor
Excellent
signals
WLANs Security Protocol
No Encryption(Open
System Authentication)
WEP(Shared Key
Authentication)
Noise(Poor Signals)
IEEE 802.11i
(WPA(TKIP))
No Encryption(Open
System Authentication)
Duration Time in Seconds
No encryption
10.57
10.76
17.35
17.71
16.1
AES
18.94
18.5
45.93
29.28
25.94
DES
14.38
12.55
21.17
20.72
21.07
RC2
18.82
18.38
61.31
29.29
31.92
3DES
18.05
17.75
30.87
27.47
32.45
BF
10.68
10.93
17.49
19.98
13.93
RC6
10.84
11.13
18.26
20
15.09
Figure 11. Power consumption for Encrypting different Text
document Files in µJoule/Byte with data transmission.
5.1.4. Results Analysis for Text Data
The results show the superiority of Blowfish algorithm
over other algorithms in terms of the power
consumption, processing time, and throughput in case
of encryption and decryption(when the same data is
encrypted by using Blowfish and AES, it is found that
Blowfish requires approximately 16% of the power
which is consumed for AES and 34% in case of
decryption). Another point can be noticed here that

Wireless Network Security Still Has no Clothes 119
RC6 requires less power ,and less time than all
algorithms except Blowfish (when the same data is
encrypted by using RC6 and AES ,it is found that RC6
requires approximately 58% of the power which is
consumed for AES and 87% in case of decryption). A
third point can be noticed here that AES has an
advantage over other 3DES, DES and RC2 in terms of
power consumption, time consumption, and throughput
in case of encryption and decryption. A fourth point
can be noticed here that 3DES has low performance in
terms of power consumption and throughput when
compared with DES in both cases. It requires always
more time than DES because of its triple phase
encryption characteristics. Finally, it is found that RC2
has low performance and low throughput when
compared with other five algorithms in spite of the
small key size used.
Also, there is insignificant difference in
performance of different symmetric key schemes in
case of data transmission. Even under the scenario of
data transfer by using the two architectures -BBS
architectures and ad-hoc architectures. It would be
advisable to use Blowfish and RC6. When the
encrypted data is transmitted by using Blow fish, RC6,
and AES, it is found that RC6 and Blow fish require
approximately 56% of the time consumption which is
consumed for AES in case of ad- hoc architecture
(8.2.11 standard using open system authentication and
shared key authentication with excellent signals).
When the encrypted data is transmitted using Blow
fish, RC6, and AES, it is found that RC6 and Blow fish
require approximately 68% of the time consumption
which is consumed for AES in case of BBS
architecture (802.11i using WPA/TKIP with excellent
signals). In case of ad hoc mode (poor signal) , it is
found that transmission time are increased
approximately to double of open and shared key
authentication in ad hoc mod using excellent signals.
5.2. The Effect of Changing File Type (video)
on Power Consumption.
5.2.1. Encryption of Different Video Files (.wav files
-Different Sizes)
•Encryption Throughput.Now a comparison
between other types of data (Video files) will be
made to check which one can perform better than
other algorithms in this case. Experimental results
for video data type are shown in figure 12 at
encryption.
•Power Consumption (µJoule/Byte).The performance
of cryptographic algorithms in terms of Power
consumption for encryption process using a
different video block size in µJoule/Byte are shown
in figure 13.
•Power Consumption (Percentage of Battery
Consumed). The performance of cryptographic
algorithms in terms of Power consumption for
encryption process by Battery consumed per
iteration for different video block size are shown in
figure 14.
Figure 12. Throughput of each encryption algorithm
(Kilobytes/Sec) without data transmission.
Figure. 13 Power consumption for encrypting different Video Files
in µJoule/Byte without data transmission.
Figure. 14: Power consumption for encrypting different Video
Files in µJoule/Byte without data transmission.

120 International Arab Journal of e-Technology, Vol. 2, No. 2, June 2011
5.2.2. Decryption of Different Video Files (.wav
files-Different Sizes)
•Decryption Throughput .The throughputs of each
encryption algorithm to decrypt different video data
(Kilobytes/Sec) without data transmission are
calculated. Experimental results for this comparison
point are shown figure 15.
Figure. 15 Throughput of each Decryption algorithm
(Kilobytes/Sec) without data transmission.
•Power Consumption (µJoule/Byte).The Power
consumption (µJoule/Byte) for decrypting different
audio Files without data transmission are calculated.
Experimental results for this comparison point are
shown figure 16.
Figure. 16: Power consumption for Decrypting different Video
Files in µJoule/Byte without data transmission.
5.2.3. Wireless Environment
The effects of change when data transmission is taken
in consideration under different scenario are
considered. The results are shown in table 3and figure
17.
Table 3. Comparative execution times for transmission of text data
using different encryption algorithms.
Video Streaming
Data to be transmitted
ad hoc mod (802.11
standard)
BSS mode
Excellent signals
Poor
Excellent
signals
WLANs Security Protocol
No
Encryption(Open
System
Authentication)
WEP(Shared Key
Authentication)
Noise(Poor
Signals)
IEEE 802.11i
(WPA(TKIP))
No
Encryption(Open
Systems
Authentication)
Duration time in second
No
encryption
8.27
8.35
19.39
13.7
12.21
AES
14.24
16.89
26.84
27.1
21.47
DES
16
16.66
26.72
26.4
22.7
RC2
15.18
16.3
26.5
26.6
25.5
3DES
16.4
16.85
26.77
26.7
22.5
BF
8.78
9.3
16.17
14.2
12
RC6
8.49
9.36
14.13
13.9
12.68
5.2.4. Results Analysis for Video Data
The results show the superiority of Blowfish algorithm
over other algorithms in terms of the power
consumption, processing time, and throughput in case
of encryption and decryption(when the same data is
encrypted by using Blowfish and AES, it is found that
Blowfish requires approximately 24% of the power
which is consumed for AES and 16% in case of
decryption). Another point can be noticed here that
RC6 requires less power ,and less time than all
algorithms except Blowfish (when the same data is
encrypted by using RC6 and AES ,it is found that RC6
requires approximately 51% of the power which is
consumed for AES and 93% in case of decryption). A
third point can be noticed here that AES has an
advantage over other 3DES, DES and RC2 in terms of
power consumption, time consumption, and throughput
in case of encryption and decryption. A fourth point
can be noticed here that 3DES has low performance in
terms of power consumption and throughput when
compared with DES in both cases. It requires always
more time than DES because of its triple phase
encryption characteristics. Finally, it is found that RC2
has low performance and low throughput when
compared with other five algorithms in spite of the
small key size used.
Also, there is insignificant difference in
performance of different symmetric key schemes in
case of data transmission. Even under the scenario of
data transfer by using the two architectures -BBS
architectures and ad-hoc architectures. It would be

Wireless Network Security Still Has no Clothes 121
Figure 17. Power consumption for Encrypt different Video Files (micro Joule/Byte ).
advisable to use Blowfish and RC6. When the
encrypted data is transmitted by using Blow fish, RC6,
and AES, it is found that RC6 and Blow fish require
approximately 57% of the time consumption which is
consumed for AES in case of ad- hoc architecture
(8.2.11 standard using open system authentication and
shared key authentication with excellent signals).
When the encrypted data is transmitted using Blow
fish, RC6, and AES, it is found that RC6 and Blow fish
require approximately 51% of the time consumption
which is consumed for AES in case of BBS
architecture (802.11i using WPA/TKIP with excellent
signals). In case of ad hoc mode (poor signal) , it is
found that transmission time require approximately
71% of open and shared key authentication in ad hoc
mod using excellent signals.
6. Conclusions
This study presents a performance evaluation of
selected symmetric encryption algorithms on power
consumption for wireless devices. The selected
algorithms are AES, DES, and 3DES, RC6, Blowfish
and RC2. Several points can be concluded from the
experimental results.
Firstly: In the case of changing packet size (text data
.DOC file) with / without data transmission using
different architectures and different WLANs protocols,
It is found that Blowfish has better performance than
other encryption algorithms, followed by RC6 in case
of encryption time, throughput, and power
consumption for encryption and decryption.
Rijndael, an AES (Advanced Encryption standard),
is faster than 3DES, DES, and RC2.These results are
compatible with the scientific background. DES
encrypts and decrypts data faster than 3DES and RC2.
3DES is faster than RC2.RC2 turns out to be the
slowest method when the data being encrypted is
small. It has an expensive computation up front to
build a key-dependent table, which apparently is high
compared to the cost of encrypting small data. RC2 is a
variable key-length symmetric block cipher, which is
designed to be alternatives to DES. These results are
the same in encryption and decryption process with
different packet size with and with out data
transmission. When the transmission of data is
considered there was insignificant difference in
performance of different symmetric key schemes.
There is insignificant difference between open key
authentications and shared key authentication in ad hoc
Wireless LAN connection with excellent signals. in
case of changing data type such video files (.WAV
file).It is found that the result as the same as in text
and document. it was concluded that Blowfish has
better performance than other common encryption
algorithms used, followed by RC6 in case of
encryption and decryption with and with out data
transmission. When the transmission of data is
considered there was insignificant difference in
performance of different symmetric key schemes (most
of the resources are consumed for data transmission
rather than computation). There is insignificant
difference between open key authentications and
shared key authentication in ad hoc Wireless LAN
connection with excellent signals.

122 International Arab Journal of e-Technology, Vol. 2, No. 2, June 2011
Finally: In the case of data transmission under poor
signal we found transmission time increased by 70%
over open shared authentication in ad hoc mod.
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Wireless Network Security Still Has no Clothes 123
Diaa Abdul-Minaam was born on
November 23, 1982 in KafrSakr,
Sharkia, Egypt. He received the B.S
from Faculty of Computers
&Informatics, Zagazig University,
Egypt in 2004 with grade very good
with honor, and obtains master
degree in information system from faculty of
computers and information, menufia university, Egypt
in 2009 and submitted for PhD from October 2009. He
is working in Jazan University,KSA as teaching
assistance at Faculty of Computer and informatics
.Diaa has contributed more than 18+ technical papers
in the areas of wireless networks , wireless network
security, Information security and Internet applications
in international journals, international conferences,
local journals and local conferences. He majors in
Cryptography and Network Security.
Hatem Abdul-kader obtained his B.
S. and M. SC. (by research) both
in Electrical Engineering from the
Alexandria University, Faculty of
Engineering, Egypt in 1990 and
1995 respectively. He obtained his
Ph.D. degree in Electrical
Engineering also from Alexandria University, Faculty
of Engineering, and Egypt in 2001 specializing in
neural networks and applications. He is currently a
Lecturer in Information systems department, Faculty of
Computers and Information, Menoufya University,
Egypt since 2004. He has worked on a number of
research topics and consulted for a number of
organizations.
Mohiy Hadhoud, Dean, Faculty of
Computers and Information, head
of Information Technology
Department, Menoufia University,
Shebin Elkom, Egypt. He is a
member of National Computers
and Informatics Sector Planning
committee, University training supervisor. He
graduated, from the department of Electronics and
Computer Science, Southampton University, UK,
1987. Since 2001 till now he is working as a
Professor of Multimedia, Signals and image
processing and Head of the department of
Information Technology (IT), He was nominated by
the university council for the national supremacy
award, years 2003, and 2004. He is the recipient of
the university supremacy award for the year 2007.
He, among others are the recipient of the Most cited
paper award form the Digital signal processing
journal, Vol. 18, No. 4, July 2008, pp. 677-678.
ELSEVIER Publisher. Prof. Hadhoud has published
more than 110 papers in international journals,
international conferences, local journals and local
conferences. His fields of Interest: Digital Signal
Processing, 2-D Adaptive filtering, Digital Image
Processing, Digital communications, Multimedia
applications, and Information security and data hiding.