Biblio

The widespread use of smartphones has made the gadget a prime source of evidence for crime investigators. The cloud-based applications on mobile devices store a rich set of evidence in the cloud servers. The physical acquisition of Android devices reveals only minimal data of cloud-based apps. However, the artifacts collected from mobile devices can be used for data acquisition from cloud servers. This paper focuses on the forensic acquisition and analysis of cloud data of Google apps on Android devices. The proposed methodology uses the tokens extracted from the Android devices to get authenticated to the Google server bypassing the two-factor authentication scheme and access the cloud data for further analysis. Based on the investigation, we have also developed a tool to acquire, preserve and analyze cloud data in a forensically sound manner.

The rapid development of blockchain application technology promotes continuous exploration in the field of computer application science. Although it is still in the initial stage of development, the technical features of blockchain technology such as decentralization, identity verification, tamper resistance, data integrity, and security are regarded as excellent solutions to today's computer security technical problems. In this paper, we will analyze and compare blockchain data storage and cloud data processing technologies, focusing on the concept and technology of blockchain distributed data storage technology, and analyze and summarize the key issues. The results of this paper will provide a useful reference for the application and research of blockchain technology in cloud storage security.

Nowadays cloud computing has become the crucial part of IT and most important thing is information security in cloud environment. Range of users can access the facilities and use cloud according to their feasibility. Cloud computing is utilized as safe storage of information but still data security is the biggest concern, for example, secrecy, data accessibility, data integrity is considerable factor for cloud storage. Cloud service providers provide the facility to clients that they can store the data on cloud remotely and access whenever required. Due to this facility, it gets necessary to shield or cover information from unapproved access, hackers or any sort of alteration and malevolent conduct. It is inexpensive approach to store the valuable information and doesn't require any hardware and software to hold the data. it gives excellent work experience but main measure is just security. In this work security strategies have been proposed for cloud data protection, capable to overpower the shortcomings of conventional data protection algorithms and enhancing security using steganography algorithm, encryption decryption techniques, compression and file splitting technique. These techniques are utilized for effective results in data protection, Client can easily access our developed desktop application and share the information in an effective and secured way.

As an important type of cloud data, digital provenance is arousing increasing attention on improving system performance. Currently, provenance has been employed to provide cues regarding access control and to estimate data quality. However, provenance itself might also be sensitive information. Therefore, provenance might be encrypted and stored in the Cloud. In this paper, we provide a mechanism to classify cloud documents by searching specific keywords from their encrypted provenance, and we prove our scheme achieves semantic security. In term of application of the proposed techniques, considering that files are classified to store separately in the cloud, in order to facilitate the regulation and security protection for the files, the classification policies can use provenance as conditions to determine the category of a document. Such as the easiest sample policy goes like: the documents have been reviewed twice can be classified as “public accessible”, which can be accessed by the public.

Cloud is the perfect way to hold our data every day. Yet the confidentiality of our data is a big concern in the handling of cloud data. Data integrity, authentication and confidentiality are basic security threats in the cloud. Cryptography techniques and Third Party Auditor (TPA) are very useful to impose the integrity and confidentiality of data. In this paper, a system is proposed Enhancing data protection that is housed in cloud computing. The suggested solution uses the RSA algorithm and the AES algorithm to encrypt user data. The hybridization of these two algorithms allows better data protection before it is stored in the cloud. Secure hash algorithm 512 is used to compute the Hash Message Authentication Code (HMAC). A stable audit program is also introduced for Third Party Auditor (TPA) use. The suggested algorithm is applied in python programming and tested in a simple sample format. It is checked that the proposed algorithm functions well to guarantee greater data protection.

One of the significant advancements in information technology is Cloud computing, but the security issue of data storage is a big problem in the cloud environment. That is why a system is proposed in this paper for improving the security of cloud data using encryption, information concealment, and hashing functions. In the data encryption phase, we implemented hybrid encryption using the algorithm of AES symmetric encryption and the algorithm of RSA asymmetric encryption. Next, the encrypted data will be hidden in an image using LSB algorithm. In the data validation phase, we use the SHA hashing algorithm. Also, in our suggestion, we compress the data using the LZW algorithm before hiding it in the image. Thus, it allows hiding as much data as possible. By using information concealment technology and mixed encryption, we can achieve strong data security. In this paper, PSNR and SSIM values were calculated in addition to the graph to evaluate the image masking performance before and after applying the compression process. The results showed that PSNR values of stego-image are better for compressed data compared to data before compression.

In a computer world, to identify anyone by doing a job or to authenticate by checking their identification and give access to computer. Access Control model comes in to picture when require to grant the permissions to individual and complete the duties. The access control models cannot give complete security when dealing with cloud computing area, where access control model failed to handle the attributes which are requisite to inhibit access based on time and location. When the data outsourced in the cloud, the information holders expect the security and confidentiality for their outsourced data. The data will be encrypted before outsourcing on cloud, still they want control on data in cloud server, where simple encryption is not a complete solution. To irradiate these issues, unlike access control models proposed Attribute Based Encryption standards (ABE). In ABE schemes there are different types like Key Policy-ABE (KP-ABE), Cipher Text-ABE (CP-ABE) and so on. The proposed method applied the access control policy of CP-ABE with Advanced Encryption Standard and used elliptic curve for key generation by using multi stage encryption which divides the users into two domains, public and private domains and shuffling the data base records to protect from inference attacks.

Cloud storage solutions have gained momentum in recent years. However, cloud servers can not be fully trusted. Data access control have becomes one of the main impediments for further adoption. One appealing approach is to incorporate the access control into encrypted data, thus removing the need to trust the cloud servers. Among existing cryptographic solutions, Ciphertext Policy Attribute-Based Encryption (CP-ABE) is well suited for fine-grained data access control in cloud storage. As promising as it is, user revocation is a cumbersome problem that impedes its wide application. To address this issue, we design an access control system called DUR-CP-ABE, which implements identity-based User Revocation in a data owner Discretionary way. In short, the proposed solution provides the following salient features. First, user revocation enforcement is based on the discretion of the data owner, thus providing more flexibility. Second, no private key updates are needed when user revocation occurs. Third, the proposed scheme allows for group revocation of affiliated users in a batch operation. To the best of our knowledge, DUR-CP-ABE is the first CP-ABE solution to provide affiliation- based batch revocation functionality, which fits naturally into organizations' Identity and Access Management (IAM) structure. The analysis shows that the proposed access control system is provably secure and efficient in terms of computation, communi- cation and storage.

Cloud computing can be described as a distributed design that is accessible to different forms of security intrusions. An encoding technique named homomorphic encoding is used for the encoding of entities which are utilized for the accession of data from cloud server. The main problems of homomorphic encoding scheme are key organization and key allocation. Because of these issues, effectiveness of homomorphic encryption approach decreases. The encoding procedure requires the generation of input, and for this, an approach named Particle swarm optimization is implemented in the presented research study. PSO algorithms are nature encouraged meta-heuristic algorithms. These algorithms are inhabitant reliant. In these algorithms, societal activities of birds and fishes are utilized as an encouragement for the development of a technical mechanism. Relying on the superiority of computations, the results are modified with the help of algorithms which are taken from arbitrarily allocated pattern of particles. With the movement of particles around the searching area, the spontaneity is performed by utilizing a pattern of arithmetical terminology. For the generation of permanent number key for encoding, optimized PSO approach is utilized. MATLAB program is used for the implementation of PSO relied homomorphic algorithm. The investigating outcomes depicts that this technique proves very beneficial on the requisites of resource exploitation and finishing time. PSO relied homomorphic algorithm is more applicable in terms of completion time and resource utilization in comparison with homomorphic algorithm.

Searchable encryption technology can guarantee the confidentiality of cloud data and the searchability of ciphertext data, which has a very broad application prospect in cloud storage environments. However, most existing searchable encryption schemes have problems, such as excessive computational overhead and low security. In order to solve these problems, a lightweight searchable encryption scheme based on certificateless cryptosystem is proposed. The user's final private key consists of partial private key and secret value, which effectively solves the certificate management problem of the traditional cryptosystem and the key escrow problem of identity-based cryptosystem. At the same time, the introduction of third-party manager has significantly reduced the burden in the cloud server and achieved lightweight multi-user ciphertext retrieval. In addition, the data owner stores the file index in the third-party manager, while the file ciphertext is stored in the cloud server. This ensures that the file index is not known by the cloud server. The analysis results show that the scheme satisfies trapdoor indistinguishability and can resist keyword guessing attacks. Compared with similar certificateless encryption schemes, it has higher computational performance in key generation, keyword encryption, trapdoor generation and keyword search.

Searchable Encryption (SE) schemes provide security and privacy to the cloud data. The existing SE approaches enable multiple users to perform search operation by using various schemes like Broadcast Encryption (BE), Attribute-Based Encryption (ABE), etc. However, these schemes do not allow multiple users to perform the search operation over the encrypted data of multiple owners. Some SE schemes involve a Proxy Server (PS) that allow multiple users to perform the search operation. However, these approaches incur huge computational burden on PS due to the repeated encryption of the user queries for transformation purpose so as to ensure that users' query is searchable over the encrypted data of multiple owners. Hence, to eliminate this computational burden on PS, this paper proposes a secure proxy server approach that performs the search operation without transforming the user queries. This approach also returns the top-k relevant documents to the user queries by using Euclidean distance similarity approach. Based on the experimental study, this approach is efficient with respect to search time and accuracy.

The Cloud computing in simple terms is storing and accessing data through internet. The data stored in the cloud is managed by cloud service providers. Storing data in cloud saves users time and memory. But once user stores data in cloud, he loses the control over his data. Hence there must be some security issues to be handled to keep users data safely in the cloud. In this work, we projected a secure auditing system using Third Party Auditor (TPA). We used Advanced Encryption Standard (AES) algorithm for encrypting user's data and Secure Hash Algorithm (SHA-2) to compute message digest. The system is executed in Amazon EC2 cloud by creating windows server instance. The results obtained demonstrates that our proposed work is safe and takes a firm time to audit the files.

With the rapid development of computer science, Internet and information technology, the application scale of network is expanding constantly, and the data volume is increasing day by day. Therefore, the demand for data processing needs to be improved urgently, and Cloud computing and big data technology as the product of the development of computer networks came into being. However, the following data collection, storage, and the security and privacy issues in the process of use are faced with many risks. How to protect the security and privacy of cloud data has become one of the urgent problems to be solved. Aiming at the problem of security and privacy of data in cloud computing environment, the security of the data is ensured from two aspects: the storage scheme and the encryption mode of the cloud data.

With all data services of cloud, it's not only stored the data, although shared the data among the multiple users or clients, which make doubt in its integrity due to the existence of software/hardware error along with human error too. There is an existence of several mechanisms to allow data holders and public verifiers to precisely, efficiently and effectively audit integrity of cloud data without accessing the whole data from server. After all, public auditing on the integrity of shared data with pervious extant mechanisms will somehow affirm the confidential information and its identity privacy to the public verifiers. In this paper, to achieve the privacy preserving public for auditing, we intended an explanation for TPA using three way handshaking protocol through the Extensible Authentication Protocol (EAP) with liberated encryption standard. Appropriately, from the cloud, we use the VerifyProof execute by TPA to audit to certify. In addition to this mechanism, the identity of each segment in the shared data is kept private from the public verifiers. Moreover, rather than verifying the auditing task one by one, this will capable to perform, the various auditing tasks simultaneously.

With the development of cloud computing and its economic benefit, more and more companies and individuals outsource their data and computation to clouds. Meanwhile, the business way of resource outsourcing makes the data out of control from its owner and results in many security issues. The existing secure keyword search methods assume that cloud servers are curious-but-honest or partial honest, which makes them powerless to deal with the deliberately falsified or fabricated results of insider attacks. In this paper, we propose a verifiable single keyword top-k search scheme against insider attacks which can verify the integrity of search results. Data owners generate verification codes (VCs) for the corresponding files, which embed the ordered sequence information of the relevance scores between files and keywords. Then files and corresponding VCs are outsourced to cloud servers. When a data user performs a keyword search in cloud servers, the qualified result files are determined according to the relevance scores between the files and the interested keyword and then returned to the data user together with a VC. The integrity of the result files is verified by data users through reconstructing a new VC on the received files and comparing it with the received one. Performance evaluation have been conducted to demonstrate the efficiency and result redundancy of the proposed scheme.

With increasing popularity of cloud computing, the data owners are motivated to outsource their sensitive data to cloud servers for flexibility and reduced cost in data management. However, privacy is a big concern for outsourcing data to the cloud. The data owners typically encrypt documents before outsourcing for privacy-preserving. As the volume of data is increasing at a dramatic rate, it is essential to develop an efficient and reliable ciphertext search techniques, so that data owners can easily access and update cloud data. In this paper, we propose a privacy preserving multi-keyword ranked search scheme over encrypted data in cloud along with data integrity using a new authenticated data structure MIR-tree. The MIR-tree based index with including the combination of widely used vector space model and TF×IDF model in the index construction and query generation. We use inverted file index for storing word-digest, which provides efficient and fast relevance between the query and cloud data. Design an authentication set(AS) for authenticating the queries, for verifying top-k search results. Because of tree based index, our scheme achieves optimal search efficiency and reduces communication overhead for verifying the search results. The analysis shows security and efficiency of our scheme.