Sharif Digital Repository

Dynamic searchable encryption schemes enable keyword search query and update operations on encrypted data. One of their applications is to use them in cloud storage services that allow the client to store, search and update data on an external server. Due to the importance of efficiency in real-world applications, retrieving information in searchable schemes involves leakage of some information such as search and access patterns. However, with the addition of update operations (insertion and deletion), more leakages are considered for these schemes. In this regard, reducing the amount of information disclosed to the server is necessary. For this purpose, forward and backward security... 

Data outsourcing provides cost-saving and availability guarantees. However, privacy and confidentiality issues, disappoint owners from outsourcing their data. Although solutions such as CryptDB and SDB tried to provide secure and practical systems, their enforced limitations, made them useless in practice. Inability in search on encrypted data, is one of the most important existing challenges in such systems. Furthermore, the overhead of mechanisms such as FHEs, removes them from considering for any practical system. Indeed, special purpose encryptions would be the only usable mechanisms for such purposes. However, their limited functionality does not support some important required... 

In recent years, one of the research interests is ensuring the integrity of computations done on data received from multiple data sources. Limited research has been done to ensure the integrity of computations that the output depends on data generated by different data sources. However, there are many solutions for systems that the input data is generated by a single data source. In this thesis, ensuring the integrity of multi-source aggregate functions and general functions are investigated in an untrusted server. To verify the integrity of aggregate functions, first of all, we present a construction for verifying the results of linear functions using the RSA signature. It should be noted... 

With the help of cloud computing, easy and fast access to a wide range of computing resources through the network is provided for a wide range of users. Cloud computing, on the other hand, faces security challenges in protecting users' privacy and access control because the cloud service provider is not a trusted entity, so it is possible to access or disclose sensitive data. Various solutions have been proposed to simultaneously meet the above two security requirements. The most well-known solution in this field is "Attribute-Based Encryption".In this dissertation, after reviewing the existing schemes to respond to the obstacles to implementing attribute-based encryption, an attribute-based... 

In recent years, different cryptographic tools have been introduced for a wide range of cloud computing applications that can be classified based on a trade-off between performance and security. In this thesis, we introduced the private set operation schemes, and at their heart, private set intersection schemes, in the cloud computing platform. These schemes are of particular importance because they can be used as basic cryptographic schemes for a wide range of functionalities in the cloud platform. Using these schemes, the user can securely store datasets on the cloud, run set queries remotely and receive the desired results. To this end, we first modeled the syntax and the security notions... 

Data outsourcing As a cloud service, it is a solution to reduce the cost of data storage and management in small and medium organizations. One of the main concerns in this area is the privacy of data owners and the non-disclosure of information by curious (albeit trusted) public cloud service providers. Resolving this issue requires encrypting the data before sending it to the cloud server. Transferring all encrypted data to the cloud server and performing various queries after encryption imposes a lot of time, computational and storage overhead, which destroys the philosophy of outsourcing. One of the open research issues is the processing of join queries over encrypted data by the cloud... 

Data outsourcing is a process that delegates storage, retrieval, and management of data to an external storage service provider. Data outsourcing will create security challenges for data owners despite decreasing the costs. The most important security challenges in this process are to maintain the confidentiality of data in order to prevent the server's access to information and to ensure that data retrieved from the server is correct. Numerous studies have been conducted to address each of these concerns, each with specific capabilities and overheads. The presented methods generally support some parts of the database's functionality, and feature enhancement in them is along with an increase... 

As cloud computing becomes a ubiquitous technology, data outsourcing, which means delegating storage and retrieval of the data to an extraneous service provider, becomes more popular. One of the main issues in data outsourcing is preserving data confidentiality and privacy. A common solution to this problem is encrypting the data before outsourcing, but this approach prevents the service provider from doing computations on the data. A trivial solution is to transfer all of the data to the client-side and decrypt it before doing the computations, but this solution imposes a large overhead on the client-side and contradicts the philosophy of outsourcing. Till now, so many encryption schemes... 

The ever-increasing volume of data and the lack of computational and storage facilities have caused a managerial challenge to organizations. The existence of these challenges on the one hand and the increase of storage services on the other hand have compelled the organizations to delegate their storage and management of data to the server providers of cloud storage services. The outsourcing of data to servers obviates the need for purchasing exorbitant storage equipment and recruiting professional workforce in the organization. Since the organization’s data will be kept outside the organization’s ambience in case of using such services in form of outsourcing, and the data will not be under... 

Regarding to globalization concept, all companies around the world can communicate with each other, share their technologies and also compensate their production deficiencies. To achieve this goal, cloud manufacturing system have been proposed and investigated. One of the most important issues in cloud manufacturing is focusing on the service composition, in which a composition of cloud services is determined to meet customer demands. Also due to the distribution of the resources in the different points and geographic locations, considering to the production and routing which previously have been studied in the classical space is very important. Considering this, the problem is as follows:... 

With the development of science and technology and its application in IT (e.g. internet, intranet and URL) the sharing of manufacturing resources reaches higher research attention, where resource virtualization enables new possibilities in terms of collaboration. As a result of these changes, with the intention of sharing optimum allocation of cloud manufacturing resource and capability among service providers and service users, the concept of service composition was introduced. Cloud services can be combine to build virtual manufacturing chain, so a strategy focusing on the evaluation and selection of virtual manufacturing resources to fulfill given services is fundamental exercise to... 

Cloud Manufacturing is a new paradigm which under development and has been introduced as one of the promising models for providing ubiquitous, convenient, on-demand network access to a shared pool of configurable manufacturing resources (e.g, networks, servers, facilities, applications, robots, machines and services) that can be rapidly provisioned with minimal management effort and service provider’s interaction. Cloud Manufacturing is defined based on Cloud Computing. Like the Cloud Computing, Cloud Manufaturing offers a service-oriented architecture that is based on information technology (IT) in which each manufacturing resources is expressed as a service. For providing a... 

Success in a business will be met by the different factors, of which one of the most important is design and execution of a good business model upon the inauguration of each company. Indicating the commercialization of innovations and innovative commercial ideas, it shows the productivity of innovation. Outsourcing the Training management in organizations is an issue the world pioneer organizations feel its necessity. Training systems in organizations have limited resources, don't have the required knowledge and financial sufficiency for effective execution of all Training processes. Therefore, Training management outsourcing may be a good alternative for meeting perspective and facilitating... 

Recently many organizations outsource their data to an external server due to easier data maintenance. One of the security issues in data outsourcing scenario is the enforcement of data owner’s access control policies. This includes some challenges; namely, the number of keys needed to access authorized resources, efficient policy updating, write access control enforcement, user and data owner overhead, and preserving confidentiality of data and policies . Most of the existing proposed solutions address only some of these challenges, while they impose high overhead on both the data owner and users. Moreover, most of them address enfrocement of policies in form of access control matrix and... 

Infrastructural costs of data management, have led people and organizations to outsource their data. This approach is facing with some significant security challenges and risks. The goal of this research, is to present an architecture for secure outsourcing of data in a way that used methods, storage processes, query processing methods and access control mechanisms work together to preserve confidentiality and integrity of outsourced data. In this architecture, the main challenge is transparent placement of some components between client and server in order to prevent user from being aware of communication with a secured server. In order to create this degree of transparency, we need to pay... 

Data outsourcing is an approach to delegate the burden of data management to external servers. In spite of its clear advantages, data outsourcing requires security assurances including data confidentiality, query result correctness, and access control enforcement. Research proposals have identified solutions with disparate assumptions for different security requirements. It is a real obstacle towards having an integrated solution through the combination of existing approaches. The practicality of data outsourcing to the cloud is seriously affected by this challenge. In this thesis, a unified view based on secret sharing is proposed to simultaneously achieve confidentiality, correctness, and... 

In recent years, there has been a trend toward outsourcing data to the cloud provider. These companies must tackle the data security challenges. Generally these parties are assumed to be honest but curious. In past years, the research communities have been investigating different solution to ensure confidentiality.
In addition to data confidentiality access and pattern confidentiality is a high-priority issue in some cases so. potential adversary should be unable to drive information from the observed access pattern to the outsourced data. Despite the fact that there are more investigation in the field of data confidentiality, concern over data security are the rise in outsourcing data,... 

While data outsourcing provides some benefits, it suffers from new privacy and security concerns, mainly about the confidentiality and integrity of the stored sensitive data, as well as enforcing access control policies. Current solutions to these aims are not comprehensive and consider only one aspect of security requirements. A secure DBMS architecture is introduced that simultaneously considers confidentiality, integrity and access control enforcement requirements. The transparency of security functions from data owner, service providers, and applications facilitates the operationality of the solution.Additionally, a new indexing technique for character encrypted data is proposed that...