This paper develops a theory of multi-instance (mi) security and applies it to provide the ﬁrst proof-based support for the classical practice of salting in password-based cryptography. Mi-security comes into play in settings (like password-based cryptography) where it is computationally feasible to compromise a single instance, and provides a second line of defense, aiming to ensure (in the case of passwords, via salting) that the eﬀort to compromise all of some large number m of instances grows linearly with m. The ﬁrst challenge is deﬁnitions, where we suggest LORX-security as a good metric for mi security of encryption and support this claim by showing it implies other natural metrics, illustrating in the process that even lifting simple results from the si setting to the mi one calls for new techniques. Next we provide a composition-based framework to transfer standard single-instance (si) security to mi-security with the aid of a key-derivation function. Analyzing password-based KDFs from the PKCS#5 standard to show that they meet our indiﬀerentiability-style mi-security deﬁnition for KDFs, we are able to conclude with the ﬁrst proof that per password salts amplify mi-security as hoped in practice. We believe that mi-security is of interest in other domains and that this work provides the foundation for its further theoretical development and practical application.
Since the birth of elliptic curve public key cryptosystem, people have made a lot of achievements in the research of elliptic curve cryptography. There are not only theoretical research on elliptic curve cryptography [10-12], but also application research on elliptic curve cryptography [13-19]. The security of this cryptosystem is based on the difficulty of the elliptic curve discrete logarithm problem. Similarly, the security of the special parabolic curve public cryptosystem proposed in this paper is based on the difficulty of solving the special parabolic discrete logarithm problem. This paper has done some basic research work on special parabola. In the future, people can further study the special parabolic curve public cryptosystem according to the research ideas of elliptic curve public cryptosystem, and popularize and innovate it. Therefore, the establishment of special parabolic public key cryptosystem has very important theoretical and practical value and a more far-reaching development prospects. In addition, the special parabolic public key cryptosystem has the same advantages as the elliptic curve public key cryptosystem, such as higher security, smaller key volume and better
persons to do the same. Since World War I and the advent of the computer, the methods used to carry out cryptology have become increasingly complex and itsapplication more widespread. Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in practice by any adversary. It is theoretically possible to break such a system, but it is infeasible to do so by any known practical means. These schemes are therefore termed computationally secure; theoretical advances, e.g., improvements in integer factorization algorithms, and faster computing technology require these solutions to be continually adapted. There exist information-theoretically secure schemes that provably cannot be broken even with unlimited computing power—an example is the one-time pad—but these schemes are more difficult to implement than the best theoretically breakable but computationally secure mechanisms.
In a threshold signature scheme , when there are t or more than t group members, a group signature can be generated successfully. The group signature can be veri- fied by any verifier using the group public key. On the other hand, in a threshold decryption scheme [20,21], any sender of a secret message can generate a cipher-text to the group using the group public key. When there are t or more than t group members, the group cipher-text can be decrypted successfully. All existing threshold crypto- graphic algorithms [19-26] only consider the situation when all participating users are legitimate group mem- bers. In this paper, we point out that when there are more than t participating users and computed valued are re- leased asynchronously in a threshold application, an at- tacker can obtain the valid output of the application and therefore, can impersonate to be a legitimate group mem- ber without being detected.
Network security is now a very significant component in information security as it is responsible for securing all the transmissions through networked computers. It consists of provisions made in an underlying network infrastructure, adopted policies by administrator for the protection of network and network-accessible resources and many more. We went through several cryptographic techniques for better security of the network.
Shyong Jian Shyu, Hung-Wei Jiang  give formal definitions to threshold multiple-secret visual cryptographic schemes, namely -MVCS and -MVCS, using only superimposition without any additional operation in decoding process. General constructions for both schemes are designed using the skills of linear programming in which the objective functions are to minimize the pixel expansions with the constraints satisfying the revealing, concealing and security conditions in the corresponding definitions. for a given setting of k ,n and s, “which revealing list may produce the smallest pixel expansion” and “how does a revealing list affect the resultant pixel expansion” are still challenges.
If the application vendor does not readily post security information for their products there are numerous security websites that report advisories and vulnerabilities. One of the better sites is Secunia, www.secunia.com. Secunia also provides a free tool Personal Software Inspector (PSI) that will scan your machine, report out of date applications and will usually provide a link to the current update. ** NOTE – PSI is for use on personally owned machines only.
(ii)Extend the mechanism to a multilayer consensus model. The benefits of the proposed protocol is that hash function is reduced to one and password shared id being utilized in home area network controller for smart grid and only 12 packets is required to exchange which reduce the delay by one and a half. In  pairing based cryptography is presented using some application of bilinear pairings which provide some mechanism for trust delegation and confidentiality for grid computing. The problem of poor scalability in GSI architecture due to GSI authentication arising when using the security protocols. In  to improve the scalability problem a new authentication framework using bilinear pairings is presented which help to minimize the frequent communications.
.The most obvious application of a public key encryption system is confidentiality. A message that a sender encrypts using the recipient's public key can be decrypted only by the recipient's paired private key. This assumes, of course, that no flaw is discovered in the basic algorithm used. Another type of application in public-key cryptography is that of digital signature schemes. Digital signature schemes can be used for sender authentication and non repudiation. In such a scheme, a user who wants to send a message computes a digital signature for this message, and then sends this digital signature (together with the message) to the intended receiver.
This paper proposes a security enhancement system for image and text which are widely used over electronic communication. At cryptographic point of view, the combining usage of image transformation and encryption technique makes the attackers more difficult for decryption process. Moreover, it can be clearly seen that there are lower correlation and higher entropy value when the proposed transformation algorithm is applied as pre- encryption step according to the analytical results. On the other hand, at the steganography point of view, the attackers cannot be easily suspicious the existence of hidden information as the encrypted cover is used for hiding the secret message. Thus, it can achieve the security requirements such as confidentiality of hidden message. Therefore, the proposed system can be applied in many security awareness application areas. In this system, only two image file types such as jpeg and bmp can be used for image cover. As further extension, the proposed block-based transformation algorithm can be tested together with other cryptographic encryption algorithms.
With the explosive growth in the Internet, network and data security have become an inevitable concern for any organization whose internal private network is connected to the Internet. The security for the data has become highly important. User’s data privacy is a central question over cloud. With more mathematical tools, cryptographic schemes are getting more versatile and often involve multiple keys for a single application. The paper presented various schemes which are used in cryptography for Network security purpose. Encrypt message with strongly secure key which is known only by sending and recipient end, is a significant aspect to acquire robust security in cloud. The secure exchange of key between sender and receiver is an important task. The key management helps to maintain confidentiality of secret International Transaction of Electrical and Computer Engineers System 11. It can also check integrity of the exchanged message to verify the authenticity. Network security covers the use of cryptographic algorithm in network protocols and network applications.
Android GinMaster (short for GingerMaster) is a Trojan application family that is primarily distributed through Chinese third party stores that infects Android devices. It was originally named GingerMaster as it attacked Android version 2.3 which was named Gingerbread. The attacks were first found in 2011 and continued for over 2 years. The newer variants of GinMaster were able to avoid detection by most anti-virus software in order to get into devices. Using polymorphic tecchniques, the program would obfuscate class names for infected objects and randomize package names and certificates for applications. Other functionality of this malware was to steal confidential information, gain more permissions on the device, and install applications without user approval [Yu13]. There are many other similar Trojan or other malicious applications and GinMaster is just a single example of this type of problem. Other general categories of Android malware are Rootkit, Trojan spy, Malicious downloader, Click fraudster, Data stealer, and Premium service abuser. Users should always double check an application's permissions and whether or not they are getting the application from a trusted source before downloading.
helps to secure the application’s in the computers. With the help of this software, user can restrict other illegal user for accessing applications from their windows system. This software allows authorized user to lock/unlock the installed application in their computer. This software will use Windows Registry for invoking security in Windows OperatingSystem. Our main objective is here to locking/ unlocking the USB, control panel and registry also. By changing the registry value’s, authorized user can deny unauthorized user to access particular applications. This software provides effective GUI to easily manage USB devices access using Registry of Windows OS. It provides high level security by applying dual level authentication methods :Image based password and Text based password The basis of these mechanism we will going to implement software which provides powerful security mechanism for Lock/Unlock system as well as user’s application and USB also and Enabling/Disabling control panel and provide system information.
Basically kernel helps in connecting the software application with the hardware application of the computer. Kernel provide a basic level of control over all the computer’s hardware devices so that an application program can interact with hardware easily without any problem regarding any software. It also helps in managing the memory of the hardware basically it determine which programs get access to which hardware resources. Kernel also helps in set up or reset the CPU operating states for optimal operations at all times , it also help in organizes the data for long term non volatile resources with file systems on such media as disks , tapes ,flash memory ,etc.
Technology, Bluetooth, Edge, 3G, Wi-Fi, Camera and GPS etc . to assist the developers for higher package development automaton provides automaton package development kit (SDK). It provides Java programming language for application development . The automaton package development kit includes a computer programme, libraries, a French telephone individual supported QEMU (Quick Emulator), documentation, sample code, and tutorials . Android could be a freely downloadable open supply package stack for mobile devices that has associate degree package, middleware and key application supported UNIX operatingsystem and Java. Google purchased the developer of automaton in 2005, and automaton was unveiled in 2007. Google discharged the automaton code as ASCII text file below the Apache License. Automaton has varied developers writing applications (apps) everywhere the planet. Initial of all the developers write their script in Java, and so transfer the apps from the third party sites or on-line stores. In Feb 2012, 450,000 apps were on the market for automaton however the calculable variety of downloads since Dec, 2011 was quite ten billion. There area unit over three hundred million Androids in use and over 850,000 devices activated a day. Automaton is that the one among the foremost used mobile package with a market share of forty eighth and Over 400,000 applications on the market in Google play store. Automaton apps are put in over ten billion times and canopy a massive vary of classes from games and diversion to money and business services. Automaton package development and therefore the Google Play Market are comparatively open and unrestricted. This offers each developers and users a lot of flexibility and freedom, however conjointly creates vital security challenges.
Abstract— Data security has become a most important issue in data communication especially in the field of Computer Network. The data can have many forms such as text, image, and sound etc. There are many cryptosystems exists to protect data; out of those Visual Cryptography (VC) is a popular technique to protect image based data. It splits the secret image into shares in encryption process and the original image can be retrieved by stacking the required number of shares at the time of decryption. Steganography is another method of cryptosystem used to protect data. It hides the secret inside another data. It makes the secret invisible to users. But in the rapid expansion of cryptanalysis and steganalysis, data is still very insecure in some state of affairs. Hence, to provide a strong security mechanism a hybrid approach using the feature of VC and steganography techniques is wise to adopt. This paper studies the visual cryptography scheme, steganography scheme and various hybrid approaches for data security especially for image based data.
The art of protecting information by transforming it (encrypting it) into an unreadable format, called cipher text. Only those who possess a secret key can decipher (or decrypt) the message into plain text. Encrypted messages can sometimes be broken by cryptanalysis, also called code breaking, although modern cryptography techniques are virtually unbreakable. Cryptography, then, not only protects data from theft or alteration, but can also be used for user authentication. There are, in general, three types of cryptographic schemes typically used to accomplish these goals: secret key (or symmetric) cryptography, public-key (or asymmetric) cryptography, and hash functions, each of which is described below. In all cases, the initial unencrypted data is referred to as plaintext. It is encrypted into cipher text, which will in turn (usually) be decrypted into usable plaintext.
2. T.Godhavari et al.  has shown about a unique quantitative security analysis for the quantum transceiver model proposed for quantum based secure information transmission. In this model follows the same security analysis as BB84 protocol. The advantage of this model is that the less number of Qubits are communicated and also check bits are added. If this model is implemented practically, lesser Qubits may be enough to get the required security level when compared to BB84 protocol. It emphasizes about the different security level to meet the end user requirement and low-level parameters of a typical QC system.
Computers have undoubtedly become ubiquitous in today’s world and as a result, most of this information is made electronic. Furthermore, with the advent of the internet, this information is now distributed. Authorized users can now send and retrieve information from a distance using computer networks. Although the three aforementioned security goals- confidentiality, integrity and availability- still remain of prime importance, they now have some new dimensions. Not only do the computers containing the data need to be secure, the network also needs to be equally secure.