Date post: | 06-Apr-2018 |
Category: |
Documents |
Upload: | geethanjalisam |
View: | 218 times |
Download: | 0 times |
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 1/22
SECURED WIRELESS DATA SECURED WIRELESS DATA
COMMUNICATION USINGCOMMUNICATION USING
CRYPTOGRAPHY CRYPTOGRAPHY
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 2/22
INTRODUCTION:INTRODUCTION:
Data communication is the conveyance of any
kind of information from one space to another.
Although the computers can be interconnected
through a traditional cables, the cost of installingsuch cables is very high.
Also, the use of cables requires theirmaintenance to protect them fromunintentional breaks and loss of signal transfer.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 3/22
y Data communication is established
between two PC·s using Radio Frequency(RF) wireless technology.
y The wireless communication is secured
in the sense that the data to betransmitted is encrypted using anencryption algorithm.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 4/22
CryptographyCryptography
y Cryptography is a tool that can be used to keepinformation confidential and to ensure itsintegrity and authenticity.
y All modern cryptographic systems are based onKerckhoff's principle of having a publicly-knownalgorithm and a secret key.
y Many cryptographic algorithms use complex
transformations involving substitutions andpermutations to transform the plaintext intothe ciphertext
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 5/22
y Cryptography involves the process of encryption and decryption.
y It is carried out using algorithms
y Cryptographic algorithms are of two
types:
Symmetric (private)
Asymmetric (public)
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 6/22
Symmetric Cryptographic AlgorithmSymmetric Cryptographic Algorithm
y In this algorithm same secret key is used toencrypt and decrypt information.
y A secret key can be a number, a word or just a
string of random letters.y The disadvantage of this algorithm is that if the
secret key is discovered all messages can bedecrypted.
y There are two types of symmetric algorithms
Stream Algorithms
Block Algorithms
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 7/22
Stream ciphers:Stream ciphers:
y This operates on the basis of a time varyinginformation applied to individual bits of plaintext.
y These are better suited for secure transmissionof data over error prone communication .
Block ciphers:
In this the plain text is divided into large blocks
consisting of fixed number of bits. Succesiveblocks of plain text are encrypted using thesame secret key.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 8/22
Asymmetric EncryptionAsymmetric Encryption
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 9/22
BLOCK DIAGRAMBLOCK DIAGRAM
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 10/22
OperationOperation
y
Initially the sender one who wants tosend the information sends the data using
serial port of PC.
y Then the data is given to microcontroller
using RS ² 232 cable, and later is given toMAX ² 232 for level conversion.
y Microcontroller performs the task of
encryption at transmitter side and sendsthe encrypted data through i/o port to
RF-transmitter
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 11/22
y Here the algorithm used for encryptionand decryption is RC4.
y RC4 is a stream cipher, symmetric keyalgorithm.
y This algorithm produces a stream of
pseudo-random values. The input stream
is XORed with these values, bit by bit.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 12/22
y The steps for RC4 encryption algorithm is
as follows:
y Get the data to be encrypted and theselected key.
y Create two string arrays.
y Initiate one array with numbers from 0 to255.
y Fill the other array with the selected key.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 13/22
y
Fill the other array with the selected key.y Randomize the first array depending on
the array of the key.
y
Randomize the first array within itself togenerate the final key stream.
y XOR the final key stream with the data to
be encrypted to give cipher text.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 14/22
y Then at receiver side the data encrypted
is given to RF-receiver then that gives thedata to microcontroller through i/o port.
y There microcontroller decrypts the dataand gives that to pc again.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 15/22
y Here the RF-transceiver works at thefrequency of 433Mhz
y This wireless transmission is applicable to
100 feet distance onlyy This uses ASK modulation process for RF
transmission
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 16/22
PIC Microcontroller Core Features:PIC Microcontroller Core Features:
y High-performance RISC CPU
y Only 35 single word instructions to learn
y All single cycle instructions except for program brancheswhich are two cycle
y Operating speed: DC - 20 MHz clock input DC - 200 nsinstruction cycle
y Up to 8K x 14 words of FLASH Program Memory,
y Up to 368 x 8 bytes of Data Memory (RAM)y Up to 256 x 8 bytes of EEPROM data memory
y Pinout compatible to the PIC16C73B/74B/76/77
y Interrupt capability (up to 14 sources)
y Eight level deep hardware stack
y Direct, indirect and relative addressing modesy Power-on Reset (POR)
y Power-up Timer (PWRT) and Oscillator Start-up Timer(OST)
y Watchdog Timer (WDT) with its own on-chip RC oscillator
for reliable operation
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 17/22
y Programmable code-protection
y Power saving SLEEP mode
y Selectable oscillator options
y Low-power, high-speed CMOS FLASH/EEPROM technology
y Fully static design
y In-Circuit Serial Programming (ICSP) via two pins
y Single 5V In-Circuit Serial Programming capability
y In-Circuit Debugging via two pins
y Processor read/write access to program memory
y Wide operating voltage range: 2.0V to 5.5V
y High Sink/Source Current: 25 mA
y Commercial and Industrial temperature ranges
y
Low-power consumption:y < 2 mA typical @ 5V, 4 MHz
y 20 mA typical @ 3V, 32 k Hz
y < 1 mA typical standby current
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 18/22
Peripheral FeaturesPeripheral Features
y Timer0: 8-bit timer/counter with 8-bit prescaler
y
Timer1: 6-bit timer/counter with prescaler, can beincremented during sleep via external crystal/clock
y Timer2: 8-bit timer/counter with 8-bit period register, pre-scalar and post-scalar
y Two Capture, Compare, PWM modules
y Capture is 6-bit, max. resolution is 12.5 ns
y Compare is 6-bit, max. resolution is 200 ns
y PWM max. resolution is 10-bit
y 10-bit multi-channel Analog-to-Digital converter
y Synchronous Serial Port (SSP) with SPI (Master Mode) andI2C (Master/Slave)
y Universal Synchronous Asynchronous Receiver Transmitter(USART/SCI) with 9-bit address detection
y Parallel Slave Port (PSP) 8-bits wide, with external RD, WRand CS controls (40/44-pin only)
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 19/22
Pin layout of PIC16F877APin layout of PIC16F877A
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 20/22
Architecture of PIC 16F877AArchitecture of PIC 16F877A
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 21/22
Advantages:Advantages:
y Information can be transmitted securelywith in a limited range.
y Simple to implement.
Disadvantages:
It is applicable only to shorter distances.
8/3/2019 New Secured Wireless Data Communication Using Cryptography (1)
http://slidepdf.com/reader/full/new-secured-wireless-data-communication-using-cryptography-1 22/22
ConclusionConclusion
y Thus the information can be transmittedsecurely using this project.