Decryption Procedure Research Articles

Acceleration of Inner-Pairing Product Operation for Secure Biometric Verification.

With the recent advances in mobile technologies, biometric verification is being adopted in many smart devices as a means for authenticating their owners. As biometric data leakage may cause stringent privacy issues, many proposals have been offered to guarantee the security of stored biometric data, i.e., biometric template. One of the most promising solutions is the use of a remote server that stores the template in an encrypted form and performs a biometric comparison on the ciphertext domain, using recently proposed functional encryption (FE) techniques. However, the drawback of this approach is that considerable computation is required for the inner-pairing product operation used for the decryption procedure of the underlying FE, which is performed in the authentication phase. In this paper, we propose an enhanced method to accelerate the inner-pairing product computation and apply it to expedite the decryption operation of FE and for faster remote biometric verification. The following two important observations are the basis for our improvement—one of the two arguments for the decryption operation does not frequently change over authentication sessions, and we only need to evaluate the product of multiple pairings, rather than individual pairings. From the results of our experiments, the proposed method reduces the time required to compute an inner-pairing product by 30.7%, compared to the previous best method. With this improvement, the time required for biometric verification is expected to decrease by up to 10.0%, compared to a naive method.

Efficient Hierarchical and Time-Sensitive Data Sharing with User Revocation in Mobile Crowdsensing

Recently, cloud-based mobile crowdsensing (MCS) has developed into a promising paradigm which can provide convenient data sensing, collection, storage, and sharing services for resource-constrained terminates. Nevertheless, it also inflicts many security concerns such as illegal access toward user secret and privacy. To protect shared data against unauthorized accesses, many studies on Ciphertext-Policy Attribute-Based Encryption (CP-ABE) have been proposed to achieve data sharing granularity. However, providing a scalable and time-sensitive data-sharing scheme across hierarchical users with compound attribute sets and revocability remains a big issue. In this paper, we investigate this challenge and propose a hierarchical and time-sensitive CP-ABE scheme, named HTR-DAC, which is characteristics of time-sensitive data access control with scalability, revocability, and high efficiency. Particularly, we propose a time-sensitive CP-ABE for hierarchical structured users with recursive attribute sets. Moreover, we design a robust revocable mechanism to achieve direct user revocation in our scheme. We also integrate verifiable outsourced decryption to improve efficiency and guarantee correctness in decryption procedure. Extensive security and performance analysis is presented to demonstrate the security requirement satisfaction and high efficiency for our data-sharing scheme in MCS.

Optical multimodal biometric encryption that uses digital holography

In this paper, we propose an optical multimodal biometric encryption technique which uses digital holography (DH) for multiple biometric recording and successive optical encryption methods, by means of keys generated from biometric data. Physiological biometrics, such as fingerprints or iris scans, along with behavioral biometrics such as voice, are recorded simultaneously as multimodal biometrics, using multi-parameter off-axis DH. Moreover, multiple biometrics embedded in the same holograms are encrypted using the Fresnel domain double random phase encoding method, in which keys are generated from biometric data via a phase retrieval algorithm. By employing the decryption procedure for this encoding method, along with the correct keys and reconstruction parameters of DH, the original multimodal biometrics can be successfully retrieved . The proposed method provides multimodal biometrics with a higher level of security by availing itself of the advantages of optical techniques. Our proposed multimodal biometric security scheme is demonstrated and validated by the results of the optical recording and encryption of biometric data presented below.

A Hybrid Cryptosystem Using Vigenère Cipher and Rabin-p Algorithm in Securing BMP Files

Vigenère cipher is a classical cryptography algorithm and similar to other classical algorithms, it produces smaller but less secure ciphertexts than a public key cryptography algorithm. Meanwhile, Rabin-p is a public key cryptography algorithm with a stronger encryption than Vigenère cipher. Nevertheless, as a public key algorithm, Rabin-p is inefficient to encrypt vast amounts of messages such as BMP image files, since the size of the cipherimages will increase manyfold and this would lead to a problem in storing and sending the cipherimages. To overcome these problems, in this study, we combined the Vigenère cipher and the Rabin-p algorithm in a hybrid cryptosystem scheme. In the experiment, the Vigenère cipher was used to encrypt the BMP files and the Rabin-p algorithm was used to encrypt the Vigenère keys. The result showed that the size of the cipherimages did not increase and the decryption procedure could recover the original BMP files while maintaining their integrity.

Data Encryption to Decryption by using Laplace Transform

In this paper, we introduce an encryption and decryption procedure with high security by mathematical model, using Laplace transformation and Inverse Laplace Transformation for the given transforming data from one end to other end. We also give an example. Here we convert plain text to ASCII code. We take two primes as a primary key for encryption and decrypt in of the original data.

A Retrospect of Prominent Cloud Security Algorithms

The concept of Cloud Computing has been distinguished as one of the major computing models in recent years. This distinguish comes as a reflection of a rapid and intense interest from academic and industrial organisations which present it as an active area of research. Security has been always raised as one of the most critical issues of cloud computing where resolving such an issue would result in a constant growth in the use and popularity of cloud. Furthermore, issues related to service availability and interoperability has gained a substantial interest. Failing to address such issues would jeopardise consumers’ satisfactions. This article mainly discusses the causes of obstacles and challenges related to security, reliability, privacy and service availability. In this work, we analyse and compare the performance of selected algorithms over “Google App Engine” which is a web framework and could computing platform. A comparative analysis of the efficiency of Advanced Encryption Standard “AES” (Rigndael), Rivest-Shamir-Adleman “RSA” and Triple Data Encryption “DES” have been performed locally and over the cloud as well. The efficiency analyses covered encryption and decryption procedures separately. Experiments results are given to analyses the effectiveness of each algorithm. The results show that Triple DES manifested a higher time efficiency ratio over cloud when subjected to different data loads compares to AES and RSA.

Public-key cryptosystem based on quantum BCH codes and its quantum digital signature

There is a security threat to the traditional cryptography because of the emergence of quantum computation. Quantum computers can break through many cryptosystems based on mathematical puzzles. The post-cryptography has been established for the sake of the security. It has been proved that McEliece public-key cryptosystem based on error-correcting codes can resist quantum attacks. In this paper, several new generating algorithms of the quantum Bose-Chaudhuri-Hocquenghem (BCH) codes have been proposed, and the quantum BCH codes can correct the errors including bit-flip and phase-flip. At the same time, the quantum McEliece public-key cryptosystem and quantum Niederreiter public key cryptosystem have been designed by us on the basis of quantum BCH codes in this paper, and their encryption and decryption procedures are created in detail. Our cryptosystem not only retains the advantages of postquantum computation, but also can encrypt or decrypt in quantum state. From the perspective of computational complexity theory, both cryptosystems can resist the attacks of Shor algorithm and Grover algorithm very well. The Niederreiter classical digital signature is designed by us according to the structure characteristics of quantum BCH codes.

Practical Privacy-Preserving Face Authentication for Smartphones Secure Against Malicious Clients

We propose a privacy-preserving face authentication system for smartphones that guarantees security against malicious clients. Using the proposed system, a face feature vector is stored on a remote server in encrypted form. To guarantee security against an honest-but-curious server who may try to learn the private feature vector, we perform a Euclidean distance-based matching score computation on encrypted feature vectors using homomorphic encryption. To provide security against malicious clients, we adopt a blinding technique. We implement the proposed system on a mobile client and a desktop server. Through an experiment with real-world participants, we demonstrate that secure face verification can be completed in real time (within 1.3 s) even when a smartphone is involved, with an Equal Error Rate (EER) of 3.04%. In further experiments with two public face datasets, CFP and ORL, face verification is completed in approximately 1 s with EER of 1.17% and 0.37%, respectively. Our system is two orders of magnitude faster than previous privacy-preserving face verification method with the same security assumptions and functionalities. To achieve this secure real-time computation, we improve the Catalano-Fiore transformation which converts a linear homomorphic encryption scheme into a quadratic scheme, and parallelize the decryption procedure of our system.

Efficient Image Encryption Scheme Using Henon Map, Dynamic S-Boxes and Elliptic Curve Cryptography

Image encryption schemes can be vulnerable to a variety of cryptanalysis attacks. The use of key-dependent dynamic S-boxes has been shown to improve security. Threats of chosen-plaintext and chosen-ciphertext attacks still linger. In this paper, we present an efficient algorithm for constructing secure dynamic S-boxes derived from Henon map. We use the proposed dynamic S-box to construct an image encryption scheme that includes a novel combination of security features to resist chosen-plaintext and chosen-ciphertext attacks. Namely, a hash verification step at the end of the decryption procedure effectively thwarts chosen-ciphertext attacks. The hash also serves as an image dependent initialization for the keystream, which together with using an image dependent S-box resist known-plaintext attacks. Furthermore, encryption keys are protected against cryptanalysis using elliptic curve cryptography (ECC).Therefore, the recovery of secret keys is as hard as the elliptic curve discrete logarithm problem even in the unlikely case of the recovery of the temporary S-box or keystream. Our evaluation of the proposed image encryption scheme reveals that it achieves a higher security standard than existing techniques. Moreover, the proposed scheme is computationally efficient with encryption throughput approaching 60 MB/s.

Computational Intelligence based Lossless Regeneration (CILR) of Blocked Gingivitis Intraoral Image Transportation

<p>This paper presented that an intraoral image has been wrapped during wireless transportation with an encryption tool with an added essence of lossless regeneration property. Threshold based cryptographic transportation has provided the construction of reliable and robust medical data communication system. The accumulation of threshold shares only would result to the formation of the intraoral gingivitis image at the receivers’ end. The proposed technique dealt with the generation of n number of partial shares by creating a unique frame structure by the dentist / physician. Additional feature has been proposed on the computational lossless transportation.The existing techniques cause a high computational complexity. The proposed technique ensured the lossless regeneration property while blocked gingivitis image sharing. Filling of bits have been incorporated to ensure the static sized homogeneous blocks of intraoral gingivitis image. A graphical masking method had been deployed, followed by successive decryption procedure on minimum threshold shares that ensure lossless data regeneration. This can guide the dental treatment with enhanced accuracy. Different types of statistical testing like entropy analysis and histogram analysis confirms the exhibition of authenticity, confidentiality, and integrity of our proposed technique.</p>

One-to-many image encryption with privacy-preserving homomorphic outsourced decryption based on compressed sensing

As a classical framework for signal compression and reconstruction, compressed sensing (CS) has dramatically improved the state-of-the-art in many fields such as image processing, wireless communication, medical imaging and optics. Since CS integrates data compression and encryption, CS-based cryptographic primitives have attracted great attention in recent years. Note that almost all the existing CS-based encryption schemes are one-to-one symmetric cryptosystems. Unlike traditional permutation-diffusion based symmetric cryptosystems (e.g., DES and AES), CS-based encryption schemes do not have the characteristic of high efficiency because decryption procedures require to perform complex and time-consuming reconstruction algorithms. In this paper, we break the traditional one-to-one encryption framework of CS-based cryptosystems, and present an efficient one-to-many encryption model for flexible application scenarios. Specifically, the information sender first encrypts several plaintext images simultaneously for different users according to our proposed attribute-based key distribution mechanism, and then sends the ciphertext to the cloud storage server. Any user who has one of attributes can efficiently obtain the corresponding plaintext by using an outsourced decryption server (ODS). To prevent the ODS from stealing the plaintexts for illegal activities, we employ a homomorphic transformation algorithm which can transform the original reconstruction problem into a variant one. The experimental results and the comparison with similar works demonstrate the feasibility and the superiority of the proposed scheme.

Security-enhanced optical voice encryption in various domains and comparative analysis.

Optical voice encryption based on digital holography (DH), which uses the double random phase encoding (DRPE) in the Fourier transform domain, has been proposed [Opt. Lett.42, 4619 (2017)OPLEDP0146-959210.1364/OL.42.004619]. In the present work, we propose optical voice encryption in other optical domains such as fractional Fourier, Fresnel, and gyrator transform, which convert input information into different mixed space-frequency domains. We also analyze the recording conditions of human voice and some security aspects of the scheme. An optical setup based on off-axis DH is used to record the time-series of holograms, and these holograms can visualize the sound wave propagation. Then, the different encryption domains in double random phase encoding (DRPE) are used to encrypt voice information with enhanced security. With the numerical reconstruction and decryption procedure of DRPE with all correct keys and correct orders of optical domains, the original voice information can be retrieved. The extension of voice encryption in different domains will enhance the security level and analysis of recording, and security aspects will explore the possibilities and challenges of the optical voice encryption scheme. We present simulation results for encryption of an experimentally recorded human voice in various domains.

Digital forensic analysis of encrypted database files in instant messaging applications on Windows operating systems: Case study with KakaoTalk, NateOn and QQ messenger

Instant messaging applications store users' personal data (e.g., user profile, chat messages, photos and video clips). Because those data typically include privacy sensitive information, most instant messaging applications are trying to protect the stored data in an encrypted form so that the authorized messaging application itself can only access the data. In this paper, we analyzed the locations and file formats of personal data files in three instant messaging applications (KakaoTalk, NateOn, and QQ) which are the most popularly used in China and South Korea. We particularly examined the encryption and decryption procedures for internal databases in those messaging applications through reverse-engineering. Our analysis results demonstrate how the database files of those instant messaging applications are stored and encrypted. Moreover, in the cases of KakaoTalk and NateOn applications, we found that their encrypted database files can successfully be recovered without requiring user password. We also found that QQ messenger stores the encryption key for the database files into an external server. This implementation may raise another privacy concern because users’ personal data can be freely accessed by the service provider without user consent.

УЗАГАЛЬНЕНА МОДЕЛЬ КРИПТОСИСТЕМИ ФРЕДГОЛЬМА

The problem of cyber security in the era of the creation of quantum computers is of particular relevance. Specifically, the data are at risk which are confidential or whose value depends on their integrity. In order to find a way out of the situation which happened in the article, a thorough comprehensive analysis of the current state of the known cryptosystems was carried out, based on a systematic approach. In particular, the advantages and disadvantages of models of cryptosystems which were created on the basis of cognitive cryptography are stated, the theory of dynamic chaos, constructive, quantum and post-quantum cryptography. The issue of cryptosystem models based on DNA algorithms is also raised, proxy cryptosystem models, attribute cryptosystems, packet and non-commutative cryptography. As a result of the research, it was found out that the greatest interest in terms of security today is integral cryptography. The lack of scientifically justified models of cryptosystems based on integrated cryptography has led to the development of one of these models. The model is developed on the basis of the proposed concept, which is based on the main principals of integral cryptography. As a result of the research, a generalized model of the cryptosystem was developed, which in the future is proposed to be called the cryptosystem of Fredholm. It is shown that the essence of the encryption and decryption procedures is reduced to solving the direct and inverse problem, which is described by the integral equation of Fredholm of the first-order. The article emphasizes in particular that compared to the known models of cryptosystems, the proposed model has a number of significant advantages. The first advantage is the guaranteed theoretical and practical cryptostability, which is due to the incorrectness of the inverse decryption problem. The second advantage of the proposed model is the absence of effective algorithms for cryptanalysis due to the lack of prevalence of integral cryptography in modern cyber security systems. The developed model serves the theoretical basis for the further development of appropriate cryptographic algorithms and research of their security parameters.

An Efficient Image Encryption Scheme using Projective Transformations

A new conceptual scheme of encryption-decryption of grayscale and color images is proposed. It is based on the combining use of elements of the RSA algorithm and projective transformations. Application of the latter in the proposed scheme further increases the cryptographic stability of the method. The algorithmic implementations of the method developed on the basis of the proposed scheme for both element-by-element and for two-element image encryption-decryption is presented. The simulation of the method was carried out using algorithms of element-by-element and two-element encryption-decryption of grayscale and color images. It is established that encrypted images do not have contours of the original images, which provides the requirements for encryption. In addition, the effectiveness of the decryption procedure, where the resulting images haven’t visible defects, is confirmed experimentally.

Symmetric Cryptosystem Based on Chaos Structured Phase Masks and Equal Modulus Decomposition Using Fractional Fourier Transform

Chaotic structured phase masks (CSPM), equal modulus decomposition (EMD) and fractional Fourier transform are potentially proposed to design the effective symmetric cryptosystem. The encryption and decryption process of our proposed system is completely established by using double random phase encoding (DRPE) in fractional Fourier domain. Frequently, random phase mask (RPM) are used routinely as secret key in most of the DRPE schemes. Nevertheless, RPM are not optimally robust against many attacks. Henceforth, this method utilises chaotic structured phase masks in the place of random phase masks (RPM). CSPM are assembled with the help of logistic map, Fresnel zone plates (FZP) and radial Hilbert mask (RHM) functions. To design an effectual trap door one-way function, equal modulus decomposition (EMD) is performed for encryption and decryption procedure of our cryptosystem. Various asymmetric cryptosystem was designed for EMD; but constructing EMD effectively in symmetric cryptosystem based on chaos structured phase masks and fractional Fourier transform is considered as a novel work and it is employed. As a result, the proposed symmetric cryptosystem attains high robust and withstand many attacks. Numerical simulations are exhibited in order to validate our system and support the fact that our EMD and CSPM based cryptosystem is extremely suitable for securing images.

The replacement of irreducible polynomial and affine mapping for the construction of a strong S-box

Substitution box (S-box) is a critical part of the data encryption and decryption procedures. The primary function of the S-box in advanced encryption standard algorithm is to randomize the 8-bit input into 8-bit output. This paper presents a novel approach to S-box construction based on the replacement of irreducible polynomial and affine mapping. The strength of the created S-box is assessed by applying several standard tests, e.g., balance, bijective, nonlinearity, strict avalanche criterion, and bit independence criterion-nonlinearity. The strength of the S-box outperforms those of available S-boxes.

Optical image encryption method based on incoherent imaging and polarized light encoding

We propose an incoherent encoding system for image encryption based on a polarized encoding method combined with an incoherent imaging. Incoherent imaging is the core component of this proposal, in which the incoherent point-spread function (PSF) of the imaging system serves as the main key to encode the input intensity distribution thanks to a convolution operation. An array of retarders and polarizers is placed on the input plane of the imaging structure to encrypt the polarized state of light based on Mueller polarization calculus. The proposal makes full use of randomness of polarization parameters and incoherent PSF so that a multidimensional key space is generated to deal with illegal attacks. Mueller polarization calculus and incoherent illumination of imaging structure ensure that only intensity information is manipulated. Another key advantage is that complicated processing and recording related to a complex-valued signal are avoided. The encoded information is just an intensity distribution, which is advantageous for data storage and transition because information expansion accompanying conventional encryption methods is also avoided. The decryption procedure can be performed digitally or using optoelectronic devices. Numerical simulation tests demonstrate the validity of the proposed scheme.

Fuzzy C Means clustering and Elliptic Curve Cryptography Using Privacy Preserving in Cloud

Cloud computing is the distribution of computing devices which reduce the cost for IT infrastructure. In this projected approach, the databases are measured to collecting method generate the transitional datasets. These datasets acquire the facts increase to pick the responsive data to the encryption and decryption procedure, the responsive data preferred procedure depend upon the entry value. The facts increase is integrated to get the superior bound limitation for the combined maintaining outflow. Responsive data to the elliptic curve cryptography (ECC) system to encrypt the data to isolation procedure. Encrypted data storage system is utilised to protected cloud data standards. Encrypting every transitional data sets are neither competent nor rate effectual one. From the trial outcome, the isolation defending charge of transitional datasets can be appreciably condensed by our method above obtainable ones where the entire datasets are encrypted.

Secured dynamic path planning and multi-obstacle avoidance model for UAV networks

As the number of the obstacles are increasing along with the navigation paths, the security of the communication data also increasing exponentially in the dynamic UAV networks. A large number of path planning and obstacle avoidance models have been proposed on the static and dynamic UAV networks for data communication. Most of the traditional obstacle avoidance models are independent of security for communication data or path planning procedures. Since the UAV sensitive data are stored in each sensor along with the path planning information; there exists an unauthorized access or malicious access to the sensitive data from third party applications or users. Also, traditional standard cryptographic algorithms (both symmetric and asymmetric) are not efficient to provide complete security to vast amount of UAV data dynamically due to its high computational memory and time.In this paper, a novel trust based Ant Colony optimization model was proposed to secure the sensitive UAV data against unauthorized access. In this model, a novel cipher text policy based encryption and decryption procedure is used as an extension to KP-ABE for UAV path security. Experimental results proved that the proposed trust based optimization model is better than the traditional UAV security models in terms of computational time and memory.