vinod thakuraa
TRANSCRIPT
Encryption And Decryption VINOD THAKUR (11005864),43,E1E35
Lovely Professional University
Abstract:- Everyone in this world wants to be safe and secure. Even a small kid tries to protect his toys in a safe place. The situation becomes more complicated when it comes to Multinational companies, Military, Army. Even a common man puts his maximum efforts to protect his data.One of the popular methods to protect the data in a more secure way is to encrypt the data while sending and when received, decrypt the data to retrieve the original message.Before transmitting the data, the data will be converted into an unreadable form and will be sent. At the receiving end, the reverse of encryption carries on to get back the original message. Thus the data will be protected in every way by following the encryption and decryption standard formats. The most efficient and reliable wireless communication is RF. The RF modules used here are 2.4 GHz UART. The data entered from the PC keyboard is sent to the microcontroller at the transmitter side. The microcontroller converts the data into unreadable form i.e., encrypts the data and then passes the encrypted data to the RF transmitter. At the receiver end, the RF receiver receives the data from air. The same data is sent to the microcontroller. This microcontroller receives the encrypted data, decrypts the data i.e., finally converts the data into a form suitable for the user to read. This decrypted data can be seen on the receiver PC. Thus, the data is protected while it is transmitted and received between two PCs.
Keywords—Encryption,decryption,microcontroller,Key,asymetric,symmetric.
1 .INTRODUCTION
1.1 What is wireless ?Wireless is a term used to describe telecommunications in which
electromagnetic waves (rather than some form of wire) carry the
signal over part or all of the communication path. Some monitoringdevices, such as intrusion alarms, employ acoustic waves at frequencies
above the range of human hearing; these are also sometimesclassified as wireless.Wireless technology is rapidly evolving, and is playing an increasingrole in the lives of people throughout the world. In addition, everlargernumbers of people are relying on the technology directly orindirectly. (It has been suggested that wireless is overused in somesituations, creating a social nuisance.)
1.2 Examples Of Wireless Devices• Cellular phones and pagers -- provide connectivity forportable and mobile applications, both personal and business• Global Positioning System (GPS) -- allows drivers of cars andtrucks, captains of boats and ships, and pilots of aircraft to ascertain their location anywhere on earth• Cordless computer peripherals -- the cordless mouse is acommon example; keyboards and printers can also be linkedto a computer via wireless• Cordless telephone sets -- these are limited-range devices,not to be confused with cell phones• Home-entertainment-system control boxes -- the VCRcontrol and the TV channel control are the most commonexamples; some hi-fi sound systems and FM broadcastReceivers also use this technology
• Remote garage-door openers -- one of the oldest wirelessDevices in common use by consumers; usually operates atRadio frequencies
2 Encryption
, encryption is the process of encoding messages or information in such a way that only authorized parties can read it.[1] Encryption doesn't prevent hacking but it reduces the likelihood that the hacker will be able to read the data that is encrypted.[2]:374 In an encryption scheme, the message or information, referred to as plaintext, is encrypted using an encryption algorithm, turning it into an unreadable ciphertext.[2] This is usually done with the use of an encryption key, which specifies how the message is to be encoded. Any adversary that can see the ciphertext should not be able to determine anything about the original message. An authorized party, however, is able to decode the ciphertext using a decryption algorithm, that usually requires a secret decryption key, that adversaries do not have access to. For technical reasons, an encryption scheme usually needs a key-generation algorithm to randomly produce keys.
3 Decryption
Decryption is the reverse process of encryption.It involves process of converting encoding data in to its originalform ,plaintext.
4 Kinds of encryption
Symmetric key encryption
In Symmetric-key schemes,[3] the encryption and decryption keys are the same. Thus communicating parties must agree on a secret key before they wish to communicate.
3.1 Public key encryption
Illustration of how a file or document is sent using Public key encryption.
In public-key encryption schemes, the encryption key is published for anyone to use and encrypt messages. However, only the receiving party has access to the decryption key and is capable of reading the encrypted messages.[4] Public-key encryption is a relatively recent invention: historically, all encryption schemes have been symmetric-key (also called private-key) schemes.[2]:478
One of the earliest public key encryption applications was called Pretty Good Privacy (PGP). It was written in 1991 by Phil Zimmermann and was purchased by Symantec in 2010.[5]
3.2
Working of encryptionEncryption has long been used by militaries and governments to facilitate secret communication. It is now commonly used in protecting information within many kinds of civilian systems. For example, the Computer Security Institute reported that in 2007, 71% of companies surveyed utilized encryption for some of their data in transit, and 53%
utilized encryption for some of their data in storage.[6] Encryption can be used to protect data "at rest", such as files on computers and storage devices (e.g. USB flash drives). In recent years there have been numerous reports of confidential data such as customers' personal records being exposed through loss or theft of laptops or backup drives. Encrypting such files at rest helps protect them should physical security measures fail. Digital rights management systems which prevent unauthorized use or reproduction of copyrighted material and protect software against reverse engineering (see also copy protection) is another somewhat different example of using encryption on data at rest.[citation needed]
Encryption is also used to protect data in transit, for example data being transferred via networks (e.g. the Internet, e-commerce), mobile telephones, wireless microphones, wireless intercom systems, Bluetooth devices and bank automatic teller machines. There have been numerous reports of data in transit being intercepted in recent years.[7] Encrypting data in transit also helps to secure it as it is often difficult to physically secure all access to networks.[citation needed]
3.3
Message verification
Encryption, by itself, can protect the confidentiality of messages, but other techniques are still needed to protect the integrity and authenticity of a message; for example, verification of a message authentication code (MAC) or a digital signature. Standards for cryptographic software and hardware to perform encryption are widely available, but successfully using encryption to ensure security may be a challenging problem. A
single slip-up in system design or execution can allow successful attacks. Sometimes an adversary can obtain unencrypted information without directly undoing the encryption
Digital signature and encryption must be applied at message creation time (i.e. on the same device it has been composed) to avoid tampering. Otherwise any node between the sender and the encryption agent could potentially tamper it. It should be noted that encrypting at the time of creation only adds security if the encryption device itself has not been tampered with.
4 Why do we need to encrypt more?If you don’t all ready know it, without encryption there is no such thing as privacy. At least not for your data. It’s all 1′s and 0′s but doesn’t take a genius at all to recognize the data it represents if it’s not encrypted when intercepted. And there are literally thousands of ways to intercept data, but I’ll list some common ways.
Internetis probably the most dangerous place for your data as concerned with privacy. If you don’t use a encrypted connection with the server, pretty much anybody can get their hands on your full communication. People in your local network, your internet provider, the host of the web-site you’re visiting, proxies you’re tunnelled through even if they are transparent and you don’t even notice or know, any carrier of your traffic which can be pretty much any arbitrary person for all you know because routes are chosen dynamically and you have very little to no influence on that and last but not least someone who specifically targets your communication being
either a hacker, the government or who knows who.
E-mailis pretty much the same story as for internet
Instant messagingis also just as weak as the whole rest of the internet!
WiFiis a special case all by itself. Special for the fact that it’s extremely dangerous. This is because the information is just put straight into the air for anybody to receive. With the right antenna this can even be from quite far away. Further away than you can be from the access point. Can you imagine what happens if this is unencrypted, or encrypted with some weak encryption such as wep?
USB-sticksmight get stolen or lost. Just plug ‘m in, thanks to plug ‘n play, no problem. The average grandmother can do that. Even encrypted and supposedly safe USB sticks might very well turn out to be very insecure after all.
External hard drivesas you might have figured suffer from pretty much the same issues as USB-sticks except for that less of them are out there who actually try and protect your data.
Personal Computersget stolen. But a bigger risk might be that other people use them as well. Maybe you don’t fear your husband, wife or maybe even the kids wandering around through your computer, but what about the friends and family who visit your house. Maybe even friends of friends during a party? And did you ever think about the possibility that you might
ever become under criminal or tax fraud investigation. You don’t even have to be guilty to be investigated, that’s the ‘beauty’. But then you say, I’ve got my account protected with a password and I’ve made my files private, isn’t that enough? NO! Plain simple NO! All though it will prevent the occasional access to your files it won’t stop the more determent of mind. If they have full access to the hardware, e.g. stolen computer or you’re under investigation, then it’s very easy, but even with limited access it’s possible. Some years ago at a institution we were able to retrieve a very sophisticated password from a machine with a padlock on the case, the HDD as only boot device and bios password set. And then there still is the malware that endangers your data.
Laptopsare the same as PC’s except for that they are stolen much easier, more often, get in the range of different people more easily and that customs have the right to search them if you travel abroad.
Security aspects of Wireless Communication Techniques. For the purpose of providing security to the data which is transmitted from transmitter to receiver, various secured data transmission techniques are used. These techniques are protecting the data from going into the hands of the unauthorized person. Main techniques are – Steganography and Cryptography. Steganography technique aims to transmit a message on a channel, where some other kind of information is already being transmitted. The goal of steganography is to hide messages inside other “harmless” digital media in a way that does not allow any person to even detect the presence of secret message. Steganography does not alter the structure of the secret message, but hides it inside a medium so that the change is not visible. In other words, steganography prevents an unintended recipient from
suspecting that the data exists and the security of the steganography system relies on secrecy of the data encoding system. Once the encoding system is known, the steganography system is defeated. Cryptography is the science of writing the secret message and the science of encryption and decryption . It hides the contents of a secret message from an unauthorized person but the content of the message is visible. In cryptography, the structure of a message is scrambled in such a way as to make it meaningless and unintelligible. Basically, cryptography offers the ability of transmitting information between persons in a way that prevents a third party from reading it. Cryptography is the very much important technique which provides very accurate, confidential and accountable data transfer through the wireless media. Usually the data is more secured when it is harder to discover the key. Cryptography uses different key based ciphering and deciphering algorithms .a. Asymmetric algorithm :
Also called as a public key algorithm. Here the process of encryption is performed using one key whereas the different key is used for the decryption process. Means it uses the different keys, one public key and another private key . Both the keys are used to encrypt and decrypt the data. a. Asymmetric algorithm :
Also called as a public key algorithm. Here the process of encryption is performed using one key whereas the different key is used for the decryption process. Means it uses the different keys, one public key and another private key [3]. Both the keys are used to encrypt and decrypt the data. Fig.1. Public Key Cryptographic Algorithm[3].
b. Symmetric Algorithm : Also called as a private key algorithm or the secret key cryptographic algorithm. As its name suggests, it makes the use of same key for both encryption and decryption processes [3].
Fig.2. Private Key Cryptographic Algorithm.
b.1. Block Ciphers : In block ciphers, the whole data is divided or organized into the groups or blocks, so it is called as the block ciphers .. b.2. Stream Ciphers : In stream ciphers, instead of grouping the data, only single bit data is sent at a time and so it is operated in real-time manner.
CODE MODULATION BASED
ENCRYPTION & DECRYPTION
TECHNIQUE FOR SECURE
COMMUNICATION IN WIRELESS using
RF module.
What is RF Module?An RF Module is a (usually) small electronic circuit used to transmit,receive, or transceive radio waves on one of a number of carrier frequencies.RF Modules are widely used in consumer application suchas garage door openers, wireless alarm systems, industrial remotecontrols, smart sensor applications, and wireless home automationsystems. They are often used instead of infrared remote controls as
they have the advantage of not requiring line-
of-sight operation.
Main Factor Affecting RF Module’s
PerformanceAs with any other radio-frequency device, the performance of an RFModule will depend on a number of factors. For example, by increasingthe transmitter power, a larger communication distance will beachieved. However, this will also result in a higher electrical powerdrain on the transmitter device, which will cause shorter operating lifefor battery powered devices.Also, using a higher transmit power will make the system more proneto interference with other RF devices, and may in fact possibly cause
the device to become illegal depending on the
jurisdiction.
RF Communication Block Diagram
Block Diagram Of RF Operation
A general RF communication block diagram is shown above. Since most of the encoders/decoders/microcontrollers are TTL compatible, most of the inputs by the user willbe given in TTL logic level. Thus, this TTL input is to be converted into serial data inputusing an encoder or a microcontroller. This serial data can be directly read using the RFTransmitter, which then performs ASK (in some cases FSK) modulation on it and transmitthe data through the antenna.In the receiver side, the RF Receiver receives the modulated signal through the antenna,performs all kinds of processing, filtering, demodulation, etc and gives out a serial data.This serial data is then converted to a TTL level logic data, which is the same data thatthe user has input.RF Modules are used wireless transfer data. This makes them most suitable for remotecontrol applications, as in where we need to control some machines or robots withoutgetting in touch with them (may be due to various reasons like safety, etc). Now dependingupon the type of application, the RF module is chosen. For short range wirelesscontrol applications, an ASK RF Transmitter-Receiver Module of frequency 315 MHz or
433 MHz is most suitable
How Do RF Transmitters And ReceiversWork?
An RF transmitter generates radio frequency waves in its circuits, and to this'carrier signal', it adds the information part by modulating the carrier signal. Thiscomposite signal (carrier plus information) is then fed to an antenna (aerial).The aerial induces a corresponding signal into the atmosphere, by altering theElectric and Magnetic fields at (obviously) the same frequency. The impedance of'free space' is few tens of Ohms to a few hundreds of Ohms.[Impedance may be considered analogous to resistance, but with reactive propertiesas well.] The power emitted by the transmitter can vary from a megawattor so (for VLF signals) to a few watts for handheld devices.An Rf receiver receives the signal from the atmosphere, from its own aerial.The receiver aerial is often quite simple, and the signal level is typically of a fewmicrovolts. This it tunes in (gets rid of unwanted signals and amplifies only thewanted ones).The receiver circuits then strip the information part of the signal from the carrierpart, and amplify this to a useful level for audio or video.The actual signal into the loudspeaker will be a few tens of volts. In spite of theinefficiency of loudspeakers, (often only a few %) the signal eventually appears ata level that may be heard. A background radio will be a few milliwatts of power.
Even a very loud sound is only a few watts of
radiated (sound) energy!!
9.9 Circuit Implementation9.9.1 Transmitter SectionMake the following circuit on an etched PCB. Here, we have used four switchesS1, S2, S3 and S4 to give 4-bit parallel data (D0-D3). Since the switchesare in active low state (i.e. low signal is sent when the switch is pressed), weneed to add external pull-up resistors as shown, so as to provide a high signalby default. A resistance as high as 1M ohm is required in between OSC1 andOSC2 pins. The Transmitter Enable (TE, pin 14) pin is an active low pin. Thus,it is permanently grounded, so as to enable the transistor always. The outputserial data DOUT is fed to the RF Transmitter Module directly.The most important thing lies in the address pins (A0-A7, pin1-8). Suppose wehave two wireless devices (A and B) in our house, both have different remotecontrols (AA and BB) and both implement the same type of RF module (say433 MHz). AA is the remote control of A and BB is of B. Now, we obviouslywouldn’t want AA to control B (which is the most probable case since both thedevices use same kind of RF module, having same frequency!). This is whereaddress pins come into play. There are 8 address pins, thus giving us an opportunityto have 8! (8 factorial) different and independent ways to connect to a
device, so that there is no interference. The address pins MUST have the sameaddress in both transmitter and receiver, or else the data won’t be transferred.
Refer to the receiver circuit for more details.
Receiver SectionThe circuit of the receiver is also quite simple. Capacitor C1 is used betweenVcc and GND for noise filtering. Apart from that, all the addresspins (A0-A7, pin 1-8) are grounded, just as in transmitter. This is to ensurethat the transmitted data is being received. Both the transmitterand the receiver MUST have the same address pins configuration. Pin17 (VT) is enabled whenever the receiver receives any data. The serialdata received by the RF Receiver module is directly fed to pin 14 (DIN),which is then converted into 4-bit parallel data (D0-D3). A 33k ohm
resistor is connected in between OSC1 and
OSC2.
The Very Best Application of Radio
Frequency is RFIDRadio-frequency identification (RFID) is the use of a wireless non-contactsystem that uses radio-frequency electromagnetic fields to transfer data from atag attached to an object, for the purposes of automatic identification and tracking.Some tags require no battery and are powered by the electromagnetic fieldsused to read them. Others use a local power source and emit radio waves (electromagneticradiation at radio frequencies). The tag contains electronically stored
information which can be read from up to several meters (yards) away. Unlike abar code, the tag does not need to be within line of sight of the reader and may beembedded in the tracked object.RFID tags are used in many industries. An RFID tag attached to an automobile duringproduction can be used to track its progress through the assembly line. Pharmaceuticalscan be tracked through warehouses. Livestock and pets may have tagsinjected, allowing positive identification of the animal. RFID identity cards can giveemployees access to locked areas of a building, and RF transponders mounted inautomobiles can be used to bill motorists for access to toll roads or parking. SinceRFID tags can be attached to clothing, possessions, or even implanted within people,the possibility of reading personally-linked information without consent has
raised privacy concerns.
Future OF PROJECTAs, We Know the Second thing after the Applications of any project which concernsthe most to any electronics student is the future of that project by anymeans, off course. So, Here in following chapter I’m going to Add some of thepossible Futuristic Insights Of Wireless RF Module. And, Well Try Not To Be ‘Ray
Kurzweil’ & ‘Stephen Hawking’ , This Futuristic Insight May not be Very Impressive& Innovative but this would definately be the best possible Insights Abutthe project.Identifying Objects Using RF Transmitters And Receivers and Retrieving
Data Using GSM
To provide a system for monitoring and locatingobjects using Radio Frequency (RF) transmitters and receivers,and querying about the objects using mobile phones. An objectrepresents a real world entity. This system is based on RFtransmitters that are tagged to the objects of everyday use andhave the capability of transmitting signals and a receiver thatdetects the transmission of the tagged object and stores itscorresponding location in the database which is createdspecifically for information maintenance of the tagged objects.Mobile phones are used to query the location of the taggedobject by sending a message to the Subscriber Identity Module(SIM) connected to a Global System for Mobile
Communications (GSM) modem. This GSM modem fetches thelocation and other relevant information from the database andEncapsulates this information into a message which is sent back
to the mobile phone that has requested the
information
Applications:-
GSM security
The security methods standardized for the GSM System make it the most secure cellular telecommunications standard currently available. Although the confidentiality of a call and anonymity of the GSM subscriber is only guaranteed on the radio channel, this is a major step in achieving end-to-end security.
The subscriber's anonymity is ensured through the use of temporary identification numbers. The confidentiality of the communication itself on the radio link is performed by the application of encryption algorithms and frequency hopping, which could only be realized using digital systems and signaling.
This chapter gives an outline of the security measures implemented for GSM subscribers.
The GSM network authenticates the identity of the subscriber through the use of a challenge-response mechanism. A 128-bit random number (RAND) is sent to the MS. The MS computes the 32-bit signed response (SRES) based on the encryption of the random number (RAND) with the
authentication algorithm (A3) using the individual subscriber authentication key (Ki). Upon receiving the signed response (SRES) from the subscriber, the GSM network repeats the calculation to verify the identity of the subscriber.
Note that the individual subscriber authentication key (Ki) is never transmitted over the radio channel. It is present in the subscriber's SIM, as well as the AUC, HLR, and VLR databases as previously described. If the received SRES agrees with the calculated value, the MS has been successfully authenticated and may continue. If the values do not match, the connection is terminated and an authentication failure indicated to the MS.
The calculation of the signed response is processed within the SIM. This provides enhanced security, because the confidential subscriber information such as the IMSI or the individual subscriber authentication key (Ki) is never released from the SIM during the authentication process.
Signaling and Data Confidentiality:The SIM contains the ciphering key generating algorithm (A8), which is used to produce the 64-bit ciphering key (Kc). The ciphering key is computed by applying the same random number (RAND) used in the authentication process to the ciphering key generating algorithm (A8) with the individual subscriber authentication key (Ki). As will be shown in later sections, the ciphering key (Kc) is used to encrypt and decrypt the data between the MS and BS.
An additional level of security is provided by having the means to change the ciphering key, making the system more resistant to
eavesdropping. The ciphering key may be changed at regular intervals as required by network design and security considerations. In a similar manner to the authentication process, the computation of the ciphering key (Kc) takes place internally within the SIM. Therefore, sensitive information such as the individual subscriber authentication key (Ki) is never revealed by the SIM.
Encrypted voice and data communications between the MS and the network is accomplished through use of the ciphering algorithm A5. Encrypted communication is initiated by a ciphering mode request command from the GSM network. Upon receipt of this command, the mobile station begins encryption and decryption of data using the ciphering algorithm (A5) and the ciphering key (Kc).
Subscriber Identity Confidentiality:To ensure subscriber identity confidentiality, the Temporary Mobile Subscriber Identity (TMSI) is used. The TMSI is sent to the mobile station after the authentication and encryption procedures have taken place. The mobile station responds by confirming reception of the TMSI. The TMSI is valid in the location area in which it was issued. For communications outside the location area, the Location Area Identification (LAI) is necessary in addition to the TMSI.
Securing Sensitive InformationWhile the Internet poses new challenges in information security, many of them can be addressed by the traditional arsenal of security mechanisms:
Strong user authentication to identify users
Granular access control to limit what users can see and do
Auditing for accountability Network encryption to protect the
confidentiality of sensitive data in transmission
Advantages and Disadvantages of Encryption
Advantages One advantage is that because the
file is encrypted then the device that uses it doesn’t need to be secure. This means that because the data is encrypted and secure that the means of storage or transportation of it doesn’t need to be securing which saves you money on extra protection software.
Another advantage is that by having the data encrypted it takes away the pain and worry that is associated with data breaches and the protection of intellectual property.
People consider encryption a type of confidentiality. Companies if the encrypt their data can talk and send freely via email even though it isn’t considered particularly safe. But not only being confidential or safe, having encrypted data also meets some of the business standards like the HIPAA, GLBA or Sarbox, which all require data to be secure and protected.
Basically the advantage of Encryption is that it keeps data from snoopers without compromising systems or storage devices
Disadvantages
Some of the reasons why people may not choose to encrypt their data is because on the disadvantages that encryption has, some of these disadvantages are the complexity of computer encryption, the usually, expensive cost, the ability for it to be easily changed and its inability to organize the data has been encoded.
Even though the data doesn’t need to be protected anymore because of the encryption, but instead it puts a lot of pressure on IT employees because then their top priority becomes protecting the key to the encryption. This is because if the key is lost then the data is no longer protected
CONCLUSION
In Today’s Electronic communication take important role. Today’s Communication technology the chatting system from one Place to another is easy and fast. But security is of some concern, for that we send the data by the system.So security is must in all systems whether we are transmitting the data through wired or wireless systems.So encryption and decryption plays an important role in providing security features
.
Future scope:n today’s world the protection of sensitive data is one of the most critical concerns for organizations and their customers. This, coupled with growing regulatory pressures, is forcing businesses to protect the integrity, privacy and security of critical information. As a result cryptography is emerging as the foundation for enterprise data security and compliance, and quickly becoming the foundation of security best practice. Cryptography, once seen as a specialized, esoteric discipline of information security, is finally coming of age.
No one would argue that cryptography and encryption are new technologies. It was true decades ago and it is still true today – encryption is the most reliable way to secure data. National security agencies and major financial institutions have long protected their sensitive data using cryptography and encryption. Today the use of encryption is growing rapidly, being deployed in a much wider set of industry sectors and across an increasing range of applications and
platforms. Put simply, cryptography and encryption have become one of the hottest technologies in the IT security industry – the challenge now is to ensure that IT organizations are equipped to handle this shift and are laying the groundwork today to satisfy their future needs.
Survey says
A recent independent survey conducted by industry analyst firm Aberdeen Group shows an increasing use of encryption and a growing need for centralized and automated key management.
The survey, ”Encryption and Key Management” which was co-sponsored by encryption management vendor, nCipher, found that Best-in-Class organizations (a category that Aberdeen defined as including organizations that have seen the most improvement in their IT security effectiveness over the past 12 months) demonstrated a tremendous increase in the number of applications and locations deploying cryptography in order to protect sensitive data compared with one year ago and, consequently, an increase in the number of encryption keys they have to manage.
Eighty-one percent of respondents had increased the number of applications using encryption, 50 percent had increased the number of locations implementing encryption and 71 percent had increased the number of encryption keys under management compared with one year ago
References:[1] Wireless Communications: Principles and Practice, Theodore S. Rappaport,2nd edition,2002
[2] Web Links:http://www.wikipedia.org/http://www.alldatasheet.com /
http://www.keralapolice.org/telecommunication/refpdf/CDMA%20CONCEPTShttp://www.ttivanguard.com/austinreconn/encrypt.pdf
Decryption is the reverse process of converting encoded data to its original un-encoded form, plaintext.
Decryption is the reverse process of converting encoded data to its original un-encoded form, plaintext. Decryption is the reverse process of converting encoded data to its original un-encoded form, plaintext.c
Decryption is the reverse process of converting encoded data to its original un-encoded form, plaintext
Decryption is the reverse process of converting encoded data to its original un-encoded form, plaintext
