Cryptographic Encryption Research Articles

A Hybrid Cryptographic and Digital Watermarking Technique for Securing Digital Images based on a Generated Symmetric Key

high increase in the transmission of digital data over secured and unsecured communications channels poses a lot of security and privacy concerns to both the transmitter and the receiver. Many operations engaged today in urban and warfare, be they for construction, monitory of plants, high voltage lines, military, police, fire service, intelligence etc. engages the use of surveillance systems that transmit sensitive data to and fro the command centre to the remote areas and this data in transmission needs to be secured. In this paper, we proposed a hybrid cryptographic and digital watermarking technique for securing digital images based on a Generated Symmetric Key. The cryptographic encryption technique made use of both pixel displacement and pixel encryption in securing the images that are to be stored or transmitted across secured and unsecured communications. The digital watermarking technique was used to authenticate the image. The programming and implementation was done using MATLAB.

Achieving Secrecy in Visual Secret Sharing Scheme Using Encrypted Images

Visual cryptography (VC), an emerging cryptography technology, uses the characteristics of human vision to decrypt encrypted images. Cryptography is the study of mathematical techniques related to aspects of information security such as confidentiality, data security, entity authentication, and data origin authentication, but it is not the only means of providing information security, rather one of the techniques. VC is a new technique that provides information security which uses simple algorithms unlike the complex, computationally intensive algorithms used in other techniques like traditional cryptography. Previous methods in the literature show good results for black and white VC schemes, however, they are not sufficient to be applied directly to shares due to different structures. Some methods for color VC are not satisfactory in terms of producing either meaningless shares or meaningful shares with low visual quality, leading to suspicion of encryption. Visual secret sharing encrypts a secret message into halftone image shares. This article introduces the concept of visual information pixel (VIP) synchronization and error diffusion to attain a visual cryptography encryption method that produces meaningful shares with high visual quality. VIP synchronization retains the positions of pixels carrying visual information of original images throughout the channels and error diffusion generates shares pleasant to human eyes. Comparisons with previous approaches show the superior performance of the new method.

Developing and Evaluation of New Hybrid Encryption Algorithms

Wireless Sensor networks consist of hundreds or thousands of low cost, low power and self-organizing nodes which are highly distributed. As wireless sensor networks continue to grow, so does the need for effective security mechanisms because sensor networks may interact with sensitive data. Encryption algorithms play good roles in information security systems (ISS). Those algorithms consume a significant amount of computing resources such as battery power. Wireless Sensor networks are powered by a battery which is a very limited resource. At present, various types of cryptographic algorithms provide high security to information on networks, but there are also has some drawbacks. The present asymmetric encryption methods and symmetric encryption methods can offer the security levels but with many limitations. For instance key maintenance is a great problem faced in symmetric encryption methods and less security level is the problem of asymmetric encryption methods even though key maintenance is easy. To improve the strength of these algorithms, we propose a new hybrid cryptographic algorithm in this paper. The algorithm is designed using combination of two symmetric cryptographic techniques and two Asymmetric cryptographic techniques. This protocol provides three cryptographic primitives, integrity, confidentiality and authentication. It is a hybrid encryption method where elliptical curve cryptography (ECC) and advanced encryption (AES) are combined to provide node encryption. RSA algorithm and Blowfish are combined to provide authentication and (MD5) for integrity. The results show that the proposed hybrid cryptographic algorithm gives better performance in terms of computation time and the size of cipher text.This paper tries to present a fair comparison between the new protocols with four existing different hybrid protocols according to power consumption. A comparison has been conducted for those protocols at different settings for each protocol such as different sizes of data blocks, and finally encryption/decryption speed. Experimental results are given to demonstrate the effectiveness of each algorithm.

Efficient Elliptic Curve Cryptography Encryption Framework for Cloud Computing

Cloud computing has benefited significantly from the ever-increasing capabilities of computer hardware, including faster microprocessors, larger memory capacity, and greater network bandwidth with high storage. This trend is expected to continue. Cloud computing enables the addition of colored displays to full-blown Web browsers. Some processes add embedded cloud warnings to investigate how data are stored on a local or intermediary system. For instance, all log files of a cloud computing server upload or download data, and all the sessions are stored in clear, unencrypted text on a local computer that multiple users have access to. The cloud client encrypts sessions with the standard method; however, the server does not fully protect such sessions. A high scheme with low-cost encryption and an elliptic curve is established in this study to solve this issue. A lookup table is integrated into the proposed framework.

Secure Approach for Data in Cloud Computing

computer software was not written with security in mind; but because of the increasing frequency and sophistication of malicious attacks against information systems, modern software design methodologies include security as a primary objective. With cloud computing systems seeking to meet multiple objectives, such as cost, performance, reliability, maintainability, and security, trade- offs have to be made. Any cloud server is vulnerable to an attacker with unlimited time and physical access to the server. Additionally, physical problems could cause the server to have down time. This would be a loss of availability, which is one of the key principles of the security triad — confidentiality, integrity, and availability (CIA). Availability addresses the issues that include attempts by malicious entities to control, destroy, or damage computing resources and deny legitimate access to systems. While availability is being preserved, confidentiality and integrity have to be maintained. In this paper, we propose an effective and flexible scheme opposing to its predecessor. By utilizing the homomorphic token and cryptographic encryption method achieves the integration of storage correctness insurance and error localization i.e. the misbehaving of servers. The new scheme further supports to dynamic operations on data blocks like delete, update, insert, append etc.

Twin Layer Iris Certification for Confidential Archive by Conceiving Shares (ICCA-CS)

Iris is one of the most challenging biometric techniques. In many proposed biometric recognition technique, template's are store in the database for comparison. But there exists a vital problem in storing the template in the database since it can be easily bootlegged. In order to overcome these issues a novel method for person identification by their Iris, through securely storing the template is proposed. Visual Cryptography Encryption (VCE) technique is used for securely storing the iris template. By means of VCE, shares are generated for the iris template which is stored in the database instead of storing the entire template. Shares are generated by pixel expansion method. Authentication is provided by comparing the shares. Comparison is done by using Hamming Code. So it is a very effective method of person identification. The proposed method gives an extra security in iris recognition.

(n, n) Visual Cryptography based on Alignment of Shares

According to visual cryptography the decryption is performed by human visual system. It is well known that visual cryptography encryption process generates shares. Proposed method based on alignment of shares at the time of superimposition. Using these shares the source image can be recovered only if the shares are superimposed with proper predefined alignment. Proper alignment of these shares at the time of superimposition plays an important role in finding the source image. Here, we are proposing a new way of aligning the shares for getting the source image and this is the only way to obtaining the source image.

Software Implementation of Cyclic Abelian Elliptic Curve using Matlab

of products and standards that use public-key cryptography for encryption and digital signature use RSA. The key length for secure RSA has increased over recent years ,and this has put heavier processing load on applications using RSA. Recently, a competing system has begun to challenge RSA: Elliptic curve cryptography (ECC).The principle attraction of ECC, compared to RSA, is that it appears to offer equal security for a far smaller key size, thereby reducing processor overhead. Cryptographers are interested only in elliptic curve that belongs to cyclic abelian group. This paper implements cyclic abelian elliptic curve in MATLAB. The properties of abelian group is proved over the coordinates satisfying the curve. Base points of elliptic curve are generated to prove that the elliptic curve belongs to cyclic abelian group.

Protocols and plan of quantum cryptography

Along with the development of confidentiality of data and resources, there is a need to develop systems that would provide confidentiality. Currently, the most used systems are classical cryptographic systems and encryption public key systems. However, none of these systems provides a solution for the famous 'catch 22' of cryptography. Owing to the intensive development of quantum mechanics, in the last 30 years emerged an entirely new kind of cryptography-quantum cryptography. Its greatest contribution is a possibility to discover an intercepted communication channel from a third party. The question is: is this really true? The question arises: 'If the quantum cryptography is so good, why is not widely used?' The aim of this paper is, on the one hand, to define the basic mechanisms of quantum cryptography IP, and, on the other hand, to point to the shortcomings, as they related to the opportunities of today's devices and flaws in protocols.

Color Extended Visual Cryptography Using Error Diffusion

Color visual cryptography (VC) encrypts a color secret message into n color halftone image shares. Previous methods in the literature show good results for black and white or gray scale VC schemes, however, they are not sufficient to be applied directly to color shares due to different color structures. Some methods for color visual cryptography are not satisfactory in terms of producing either meaningless shares or meaningful shares with low visual quality, leading to suspicion of encryption. This paper introduces the concept of visual information pixel (VIP) synchronization and error diffusion to attain a color visual cryptography encryption method that produces meaningful color shares with high visual quality. VIP synchronization retains the positions of pixels carrying visual information of original images throughout the color channels and error diffusion generates shares pleasant to human eyes. Comparisons with previous approaches show the superior performance of the new method.

Video JET: packet loss-resilient video joint encryption and transmission based on media-hash-embedded residual data

Media encryption technologies actively play the first line of defense in securing the access of multimedia data. Traditional cryptographic encryption can achieve provable security but is unfortunately sensitive to a single bit error, which will cause an unreliable packet to be dropped creating packet loss. In order to achieve robust media encryption, the requirement of error resilience can be achieved with error-resilient media transmission. This study proposes a video joint encryption and transmission (video JET) scheme by exploiting media hash-embedded residual data to achieve motion estimation and compensation for recovering lost packets, while maintaining format compliance and cryptographic provable security. Interestingly, since video block hash preserves the condensed content to facilitate search of similar blocks, motion estimation is implicitly performed through robust media hash matching --- which is the unique characteristic of our method. We analyze and compare the performance of resilience to (bursty) packet loss between the proposed method and forward error correction (FEC), which has been extensively employed to protect video packets over error-prone networks. The feasibility of our packet loss-resilient video JET approach is further demonstrated through experimental results.

Recovering DC Coefficients in Block-Based DCT

It is a common approach for JPEG and MPEG encryption systems to provide higher protection for dc coefficients and less protection for ac coefficients. Some authors have employed a cryptographic encryption algorithm for the dc coefficients and left the ac coefficients to techniques based on random permutation lists which are known to be weak against known-plaintext and chosen-ciphertext attacks. In this paper we show that in block-based DCT, it is possible to recover dc coefficients from ac coefficients with reasonable image quality and show the insecurity of image encryption methods which rely on the encryption of dc values using a cryptoalgorithm. The method proposed in this paper combines dc recovery from ac coefficients and the fact that ac coefficients can be recovered using a chosen ciphertext attack. We demonstrate that a method proposed by Tang to encrypt and decrypt MPEG video can be completely broken.

Balanced Boolean functions

Many common logic circuits such as adders, parity checkers and multiplexers realise Boolean functions that are true for exactly half their input combinations, and false for the other half; we refer to such functions as balanced. Recently, these functions have been shown to be very useful for testing logic circuits, and for data encryption in cryptography. Here, we present a general theory of balanced Boolean functions. We derive a necessary and sufficient condition for balance by establishing an equivalence between a balanced function f(X) and a bijection from X to itself. We then analyse the conditions under which functional compositions preserve balance, and examine some specific balance-preserving decompositions. A new characterisation of functional completeness in terms of balance is presented. Finally, we address the problem of counting equivalence classes of balanced functions.