21-08-2014, 02:25 PM
ENCRYPTION AND DECRYPTION FOR SECURE COMMUNICATION IN
WLAN PROJECT REPORT
ENCRYPTION AND DECRYPTION.pdf (Size: 389.38 KB / Downloads: 12)
ABSTRACT
This project comes into use when we want the data communication to be
protected from others. During war times, when a particular base wants to send a
message to remotely located units which belong to the same army, in between any
third party can trap the data when it is transmitted in wires or wireless.
The essence of our project comes into this particular scene of the military
world. Our project protects the data from strangers. This is achieved by incorporating
a new wireless network system in which data is code modulated and then encrypted to
get an encoded version of the data to be transmitted. This makes it have a lighter edge
over current wireless systems by making use of Bluetooth compatible ICs. At the
receiving end the PIC microcontroller will then decode the Received data and
separates the data for different units and displays the message on the display. In future
it can be enhanced to be in wireless for long distance
INTRODUCTION
The need for this project arises when we want the data communication to be
protected from others. This is highly essential in the military field and especially
during war times. Because during war periods when a particular army wants to send a
message to remotely located units which belongs to the same army, in between any
person can trap the data when it is transmitted through wires or wireless.
Our aim of the project is to protect the data from the ensnares. To accomplish
this, we have used a PC as a sender and PIC microcontroller as a receiver station. The
message to be sent is fed in to the computer for different units. The computer will
encode the data by generating a 7 bit access code for each units and the code will be
sent along with the mixed data of other unit’s message also
GENERAL CONCEPTS
One of the emerging technologies in recent days in Embedded Systems, which
is a combination of both hardware and software and perhaps additional mechanical
parts designed to perform a specific function. It provides a very cost-effective solution
to a problem. The inputs to a system can be from a device or functions call routines.
Processors used can be a micro-controller or a micro-processor or a DSP. The outputs
from the system are the actual physical data required. The memory is used to interface
the system with the database and the software code.
The technique used to send data safely across is Code Modulation, which is
the process of generating a random code for each bit of the binary 8-bit code of each
character and then interlacing them with different messages to get the modulated data.
In such a case, a strong Encryption scheme is followed by the use of code generated
for each bit, which takes more amount of time to be tapped. And thus the retrieval of
data becomes difficult for the hacker.
WIRELESS NETWORKING
Organizations of all sizes are installing and operating wireless networks,
known as wireless local area networks (WLANs) or Wi-Fi networks. Low cost, ease
of installation, flexibility are the benefits that are propelling the widespread adoption
of wireless technology. While the benefits of WLANs are substantial, wireless
technology introduces security holes that network administrators must take into
account if they are to adequately protect their organizations from hackers, cyber
terrorists, and unauthorized intruders. Wireless networks are notoriously easy to
compromise when improperly installed and operated. Once compromised, a WLAN
gives intruders an open conduit to your entire network and places all your proprietary
and mission-critical information in jeopardy. Wireless security is not impossible to
achieve. In fact, when a comprehensive, layered-security approach is implemented, a
WLAN can be more secure and easier to use and manage than a typical wired
network
THE SECURE WIRELESS NETWORK PARADIGM
Their ease of use and productivity benefits have allowed unsecured wireless
networks to slip ‘under the wire’ of good network security practices. The tendency
has been to utilize wireless network technology to extend the network beyond the
physical ports of the secure LAN. WLANs are mistakenly considered secure since
they are protected behind the firewall
from insecure Internet traffic. The problem is that WLANs provide additional entry
points for attack into the network. Physical access through your wireless network is
even easier than through your connection to the Internet – intruders can attack your
network from outside of the building!
Adequate wireless security requires that we change how we treat and secure
wireless networks. The secure wireless network paradigm demands that WLANs be
treated as unsecured networks requiring best security practice measures for access,
authentication, and encryption. As with all network security best practices, a layered
approach provides the best protection.
SIGNIFICANCE OF WIRELESS SYSTEMS
The next few years will bring dramatic changes to the technologies for
wireless data communication in the U.S.; Speeds, rates and coverage are
improving. And most enterprises have completed their back-office
automation and are now poised to extend the information to the field. Early
adopters are proving that the ROI can be very favorable when the
applications are focused on providing the right amount of data at the right
time. All of these factors will contribute to significant growth in wireless
data adoption.
For mobile workers still relying on paper systems, the payback of
wireless communications can be significant often generating 20-30% ROI. In
addition, speed of information can be critical to meeting customer
expectations on responsiveness and maintaining a competitive advantage
5.3.5.3 MAX 232 DETAILS
The Max 232 is a dual RS-232 receiver / transmitter that meets all EIA
RS232C specifications while using only a +5V power supply. It has 2 onboard
charges pump voltage converters, which generate +10V, and –10V power supplies
from a single 5V power supply. It has four level translators, two of which are RS232
transmitters that convert TTL\ CMOS input levels into + 9V RS232 outputs. The
other two level translators are RS232 receivers that convert RS232 inputs to 5V
5.3.5.2 POWER SUPPLY DETAILS
The MAX232 power supply section has 2 charge pumps the first uses external
capacitors C1 to double the +5V input to +10V with input impedance of
approximately 200Ω. The second charge pump uses external capacitor to invert +10V
to –10V with an overall output impedance of 45Ω. The best circuit uses 22µF
capacitors for C1 and C4 but the value is not critical.
Normally these capacitors are low cost aluminum electrolyte
capacitors or tantalum if size is critical. Increasing the value of C1 and C2 to
47µF will lower the output impedance of +5V to+10V doubles by about 5Ω
and +10V to -10V inverter by about 10Ω. Increasing the value of C3 and C4
lowers the ripple on the power supplies thereby lowering the 16KHz ripple on the
RS232 output. The value of C1 and C4 can be lowered to 1µF in systems where size
is critical at the expense of an additional 20Ω impedance +10V output and 40Ω
additional impedance at –10V inpu
FUTURE ENHANCEMENTS
The PIC microcontroller which is being used has to receive the data from the
base station has limited memory capacity and processing speed. This severely inhibits
the potential of the receiver. The frequency used is 433 Mhz which has a very limited
bandwidth. The use of higher bandwidth of around 3 Ghz will increase the speed of
transmission. In order to use higher bandwidth the speed of the processor must also be
increased proportionally. The presence of more memory will help the receiver to store
the received data on to the buffer. This buffer is useful if we were to present
authentication mechanism
CONCLUSION
This project aimed at Encryption and Decryption for secure communication in
WLAN has satisfied the goal. The development and implementation of this system
has given us a great satisfaction. Through our efforts, we have incorporated into the
system several features such as authentication and integrity.
The implementation of the project provides the following:
User-friendly interface
Security – Encryption of data.
Authentication – Checking for password at receiver end.