Hash Tree Research Articles

Enabling Public Audit Ability and Data Dynamics for Storage Security in Cloud Computing Data Integrity Proofs In Cloud Storage

IT has moved into next generation with cloud computing being realized. The way application software and databases are stored has been changed. Now they are stored in cloud data centers in which security is a concern from client point of view. The new phenomenon which is used to store and manage data without capital investment has brought many security challenges which are not thoroughly understood. This paper focuses on the security and integrity of data stored in cloud data servers. The data integrity verification is done by using a third party auditor who is authorized to check integrity of data periodically on behalf of client. The client of the data gets notifications from third party auditor when data integrity is lost. Not only verification of data integrity, the proposed system also supports data dynamics. The work that has been done in this line lacks data dynamics and true public auditability. The auditing task monitors data modifications, insertions and deletions. The proposed system is capable of supporting both public auditability and data dynamics. The review of literature has revealed the problems with existing systems and that is the motivation behind taking up this work. Merkle Hash Tree is used to improve block level authentication. In order to handle auditing tasks simultaneously, bilinear aggregate signature is used. This enables TPA to perform auditing concurrently for multiple clients. The experiments reveal that the proposed system is very efficient and also secure. Index Terms: Cloud computing, public audit ability, cloud storage, cloud service provider

Trustable MHT Node Identifying Scheme in DTN

As of the openness and networks infrastructure's absence of DTN's (Delay/Disrupted Tolerant Networks) network node, visiting control and identifying problem becomes the momentous safe menace of DTN networks. This thesis advanced a node identification scheme based on the trustable Merkle Hash Tree (MHT), adopting dynamic programming algorithm to conform the best binary search tree, conforming trustable Merkle Hash Tree according to the best binary search tree, and signing to the value of root node and information serial number in the Merkle Hash Tree, sending the fragmentation to the next node, and provide this fragmentation's identifying chain, information serial number to identify the fragmentation. Analyzing result shows, on the premise of ensuring the safety of Merkle Trustable Tree signature scheme, this scheme has higher safety on increasing node efficiency and resisting invalid signature.

Dynamic Security Scheme for Multicast Source Authentication

Multicast source authentication is a burning issues in multicast communication because multicast technology provide the better communication than unicast and broadcast. But its design architecture any member can send the data to all joined receivers due to publicly available IP address of group manager. To solve this hottest problems, several schemes have been existed in this category such as simple hash chaining, tree hash chaining where the attacker intensity are unchanged. In this paper, we are going to propose a improved mechanism for multicast source authentication which adapts the security level deployed based on threshold value of attack success rate. The results shows that propose approach dynamic security mechanism in multicast at minimum communication and computation overhead

A Lightweight Multidimensional Index for Complex Queries over DHTs

In this paper, we study the problem of indexing multidimensional data in P2P networks based on distributed hash tables (DHTs). We advocate the indexing approach that superimposes a multidimensional index tree on top of a DHT - a paradigm that keeps the underlying DHT intact while being able to adapt to any DHT substrate. In this context, we identify several index design issues and propose a novel indexing scheme called multidimensional Lightweight Hash Tree (m-LIGHT). First, to preserve data locality, m-LIGHT employs a clever naming mechanism that gracefully maps a tree-based index into the DHT and contributes to high efficiency in both index maintenance and query processing. Second, to tackle the load balancing issue, m-LIGHT leverages a new data-aware splitting strategy that achieves optimal load balance under a fixed index size. We present detailed algorithms for processing complex queries over the m-LIGHT index. We also conduct an extensive performance evaluation of m-LIGHT in comparison with several state-of-the-art indexing schemes. The experimental results show that m-LIGHT substantially reduces index maintenance overhead and improves query performance in terms of both bandwidth consumption and response latency.

Optimally-balanced Hash Tree Generation in Ad Hoc Networks

Ideally a hash tree is a perfect binary tree with leaves equal to power of two. Each leaf node in this type of tree can represent a mobile node in an ad hoc network. Each leaf in the tree contains hash value of mobile node’s identification (ID) and public key (PK). Such a tree can be used for authenticating PK in ad hoc networks. Most of the previous works based on hash tree assumed perfect hash tree structures, which can be used efficiently only in networks with a specific number of mobile nodes. Practically the number of mobile nodes may not be always equal to a power of two and the conventional algorithms may result in an inefficient tree structure. In this paper the issue of generating a hash tree is addressed by proposing an algorithm to generate an optimally-balanced structure for a complete hash tree. It is demonstrated through both the mathematical analysis and simulation that such a tree is optimally-balanced and can efficiently be used for public key authentication in ad hoc networks.

Highly resilient key distribution strategy for multi-level heterogeneous sensor networks by using deployment knowledge

The most important problem in the security of wireless sensor network (WSN) is to distribute keys for the sensor nodes and to establish a secure channel in an insecure environment. Since the sensor node has limited resources, for instance, low battery life and low computational power, the key distribution scheme must be designed in an efficient manner. Recently many studies added a few high-level nodes into the network, called the heterogeneous sensor network (HSN). Most of these studies considered an application for two-level HSN instead of multi-level one. In this paper, we propose some definitions for multi-level HSN, and design a novel key management strategy based on the polynomial hash tree (PHT) method by using deployment knowledge. Our proposed strategy has lower computation and communication overheads but higher connectivity and resilience.

Mining Frequent Itemsets by using Binary Search Tree Approach

Data Mining is the process of extracting hidden patterns from data. Finding frequent itemsets is computationally the most expensive step in association rule discovery . The Efficient Hashing Tree (EHT) algorithm is even faster than Apriori and FPgrowth algorithms. Its drawback is however, that the time needed to build a compact tree and the memory requirement depends upon the number of frequent 2 – itemsets. [1] The above drawbacks are rectified by using Binary Search Tree (BST) algorithm. By using this approach we can construct a binary search tree very quickly by considering the frequent itemsets. This algorithms works well for 1–itemset, 2–itemsets, 3–itemsets and more than 3–itemsets. By using this approach it requires very less memory requirement for mining frequent itemsets.

Provable Data Possession of Resource-constrained Mobile Devices in Cloud Computing

Benefited from cloud storage services, users can save their cost of buying expensive storage and application servers, as well as deploying and maintaining applications. Meanwhile they lost the physical control of their data. So effective methods are needed to verify the correctness of the data stored at cloud servers, which are the research issues the Provable Data Possession (PDP) faced. The most important features in PDP are: 1) supporting for public, unlimited numbers of times of verification; 2) supporting for dynamic data update; 3) efficiency of storage space and computing. In mobile cloud computing, mobile end-users also need the PDP service. However, the computing workloads and storage burden of client in existing PDP schemes are too heavy to be directly used by the resource-constrained mobile devices. To solve this problem, with the integration of the trusted computing technology, this paper proposes a novel public PDP scheme, in which the trusted third-party agent (TPA) takes over most of the calculations from the mobile end-users. By using bilinear signature and Merkle hash tree (MHT), the scheme aggregates the verification tokens of the data file into one small signature to reduce communication and storage burden. MHT is also helpful to support dynamic data update. In our framework, the mobile terminal devices only need to generate some secret keys and random numbers with the help of trusted platform model (TPM) chips, and the needed computing workload and storage space is fit for mobile devices. Our scheme realizes provable secure storage service for resource-constrained mobile devices in mobile cloud computing.

Enabling Public Auditability and Data Dynamics for Storage Security in Cloud Computing

Cloud Computing has been envisioned as the next-generation architecture of IT Enterprise. It moves the application software and databases to the centralized large data centers, where the management of the data and services may not be fully trustworthy. This unique paradigm brings about many new security challenges, which have not been well understood. This work studies the problem of ensuring the integrity of data storage in Cloud Computing. In particular, we consider the task of allowing a third party auditor (TPA), on behalf of the cloud client, to verify the integrity of the dynamic data stored in the cloud. The introduction of TPA eliminates the involvement of the client through the auditing of whether his data stored in the cloud are indeed intact, which can be important in achieving economies of scale for Cloud Computing. The support for data dynamics via the most general forms of data operation, such as block modification, insertion, and deletion, is also a significant step toward practicality, since services in Cloud Computing are not limited to archive or backup data only. While prior works on ensuring remote data integrity often lacks the support of either public auditability or dynamic data operations, this paper achieves both. We first identify the difficulties and potential security problems of direct extensions with fully dynamic data updates from prior works and then show how to construct an elegant verification scheme for the seamless integration of these two salient features in our protocol design. In particular, to achieve efficient data dynamics, we improve the existing proof of storage models by manipulating the classic Merkle Hash Tree construction for block tag authentication. To support efficient handling of multiple auditing tasks, we further explore the technique of bilinear aggregate signature to extend our main result into a multiuser setting, where TPA can perform multiple auditing tasks simultaneously. Extensive security and performance analysis show that the proposed schemes are highly efficient and provably secure.

Efficient Remote Attestation Mechanism with Privacy Protection

基于Merkle 哈希树提出了一种效率高、方式灵活并能保护平台隐私的远程验证机制.针对特定的目标应用场景,分析IMA(integrity measurement architecture)体系架构的不足,详细描述基于Merkle 哈希树的远程验证机制的体系架构和度量验证过程,阐述新机制对现有TPM(trusted platform module)的功能增强即TPM_HashTree 命令的功能及伪代码,并分析讨论新机制的优点.;A remote attestation mechanism, with high efficiency, flexibility and privacy protection based on Merkle hash tree is proposed in this paper. The problems of IMA (integrity measurement architecture) architecture are analyzed for a special target application scenario; followed by a detailed description of RAMT (remote attestation mechanism based on Merkle hash tree) architecture and its process of integrity measuring and verifying. The function and pseudo-code of command <em>TPM_HashTree</em>, which is a function enhancement to the existing TPM (trusted platform module), are presented for the newly proposed mechanism. The advantages of the new mechanism are analyzed and discussed.

A Tamper-Resistant Programming Language System

An important and recurring security scenario involves the need to carry out trusted computations in the context of untrusted environments. It is shown how a tamper-resistant interpreter for a programming language-currently Lisp 1.5-combined with the use of a secure coprocessor can address this problem. This solution executes the interpreter on the secure coprocessor while the code and data of the program reside in the larger memory of an associated untrusted host. This allows the coprocessor to utilize the host's memory without fear of tampering even by a hostile host. This approach has several advantages including ease of use, and the ability to provide tamper-resistance for any program that can be constructed using the language. The language approach enabled the development of two novel mechanisms for implementing tamper resistance. These mechanisms provide alternatives to pure Merkle hash trees. Simulated relative performance of the various mechanisms is provided and shows the relative merits of each mechanism.

Clustering: Applied to Data Structuring and Retrieval

Clustering is a very useful scheme for data structuring and retrieval behuhcause it can handle large volumes of multi-dimensional data and employs a very fast algorithm. Other forms of data structuring techniques include hashing and binary tree structures. However, clustering has the advantage of employing little computational storage requirements and a fast speed algorithm. In this paper, clustering, k-means clustering and the approaches to effective clustering are extensively discussed. Clustering was employed as a data grouping and retrieval strategy in the filtering of fingerprints in the Fingerprint Verification Competition 2000 database 4(a). An average penetration of 7.41% obtained from the experiment shows clearly that the clustering scheme is an effective retrieval strategy for the filtering of fingerprints.

Using Merkle Tree to Mitigate Cooperative Black-hole Attack in Wireless Mesh Networks

Security is always a major concern and a topic of hot discussion to users of Wireless Mesh Networks (WMNs). The open architecture of WMNs makes it very easy for malicious attackers to exploit the loopholes in the routing protocol. Cooperative Black-hole attack is a type of denial-of-service attack that sabotages the routing functions of the network layer in WMNs. In this paper we have focused on improving the security of one of the popular routing protocols among WMNs, Ad-hoc on demand distance vector (AODV) routing protocol and present a probable solution to this attack using Merkle hash tree.

Tertiary hash tree-based index structure for high dimensional multimedia data

Dominant features for the content-based image retrieval usually have high-dimensionality. So far, many researches have been done to index such values to support fast retrieval. Still, many existing indexing schemes are suffering from performance degradation due to the curse of dimensionality problem. As an alternative, heuristic algorithms have been proposed to calculate the answer with ‘high probability’ at the cost of accuracy. In this paper, we propose a new hash tree-based indexing structure called tertiary hash tree for indexing high-dimensional feature data. Tertiary hash tree provides several advantages compared to the traditional extendible hash structure in terms of resource usage and search performance. Through extensive experiments, we show that our proposed index structure achieves outstanding performance.

XPath Query Completeness Verification Algorithms in DAS

With the development in the application environment of database management system, the related technologies such as data management and data access have become more and more complex and the cost of maintenance has been more and more expensive. The problems that how to enable enterprises to focus on the ir expert areas and outsource the unfamiliar enterprise information systems to others , thus to save a lot of resources but receive the same quality of service s, are widely concerned by the database research and application areas. Database as a service (DAS), which means that enterprises outsource the database system to some database service providers (DSP) who manage the massive data and provide high-quality data management service becomes an important application in nowadays . To enjoy services provided by a third party, we need to ensure the correctness and completeness of query results. This paper pospose an algorithm which provides an authentication method for the query results returned from a possible malicous server on which database is outsourced and query is evaluated. The basic idea is to build some Merkle hash trees twice to verify the correctness and completeness of the query results. We have demonstrated the effectiveness of our method in experiments.

Keychain-Based Signatures for Securing BGP

As a major component of Internet routing infrastructure, the Border Gateway Protocol (BGP) is vulnerable to malicious attacks. While Secure BGP (S-BGP) provides a comprehensive framework to secure BGP, its high computational cost and low incremental deployment benefits seriously impede its wide usage in practice. Using a lightweight symmetric signature scheme, SPV is much faster than S-BGP. However, the speed boost comes at the price of prohibitively large signatures. Aggregated path authentication reduces the overhead of securing BGP in terms of both time and space, but the speed improvement is still limited by public key computation. In this paper, we propose a keychain-based signature scheme called KC-x. It has low CPU and memory overheads and provides strong incentive for incremental deployment on the Internet. As a generic framework, KC-x has the flexibility of using different signature algorithms, which can even co-exist in a hybrid deployment. We investigate two implementations of KC-x: KC-RSA based on RSA and KC-MT based on Merkle hash tree. Using real BGP workloads, our experimental results show that KC-RSA is as efficient as SAS-V (the most efficient software approach for aggregated path authentication), and KC-MT is even three times faster than SPV with 40% smaller signatures. Through the hybrid deployment of KC-MT and KC-RSA, KC-x can achieve both small signature and high processing rate for BGP speakers.

Efficient Web Log Mining Using Enhanced Apriori Algorithm with Hash Tree and Fuzzy

Web usage mining is the type of Web mining activity that involves the automatic discovery of user access patterns from one or more Web servers. In this paper we analyze the pattern using different algorithms like Apriori, Hash tree and Fuzzy and then we used enhanced Apriori algorithm to give the solution for Crisp Boundry problem with higher optimized efficiency while comparing to other algorithms.

MSSL: A framework for trusted and incentivized peer-to-peer data sharing between distrusted and selfish clients

Conventional client-server applications can be enhanced by enabling peer-to-peer data sharing between the clients, greatly reducing the scalability concern when a large number of clients access a single server. However, for these “hybrid peer-to-peer applications,” obtaining data from peer clients may not be secure, and clients may lack incentives in providing or receiving data from their peers. In this paper, we describe our mSSL framework that encompasses key security and incentive functions that hybrid peer-to-peer applications can selectively invoke based on their need. In contrast to the conventional SSL protocol that only protects client-server connections, mSSL not only supports client authentication and data confidentiality, but also ensures data integrity through a novel exploit of Merkle hash trees, all under the assumption that data sharing can be between untrustworthy clients. Moreover, with mSSL’s incentive functions, any client that provides data to its peers can also obtain accurate proofs or digital money for its service securely and reliably. Our evaluation further shows that mSSL is not only fast and effective, but also has a reasonable overhead.

LIGHT: A Query-Efficient Yet Low-Maintenance Indexing Scheme over DHTs

DHT is a widely used building block for scalable P2P systems. However, as uniform hashing employed in DHTs destroys data locality, it is not a trivial task to support complex queries (e.g., range queries and k-nearest-neighbor queries) in DHT-based P2P systems. In order to support efficient processing of such complex queries, a popular solution is to build indexes on top of the DHT. Unfortunately, existing over-DHT indexing schemes suffer from either query inefficiency or high maintenance cost. In this paper, we propose LIGhtweight Hash Tree (LIGHT)—a query-efficient yet low-maintenance indexing scheme. LIGHT employs a novel naming mechanism and a tree summarization strategy for graceful distribution of its index structure. We show through analysis that it can support various complex queries with near-optimal performance. Extensive experimental results also demonstrate that, compared with state of the art over-DHT indexing schemes, LIGHT saves 50-75 percent of index maintenance cost and substantially improves query performance in terms of both response time and bandwidth consumption. In addition, LIGHT is designed over generic DHTs and hence can be easily implemented and deployed in any DHT-based P2P system.

An efficient anonymous authentication mechanism for delay tolerant networks

Security and privacy are crucial to the wide deployments of delay tolerant networks. Without security and privacy guarantees, people are reluctant to accept such a new network paradigm. To address the security and privacy issues in delay tolerant networks, in this paper, based on ID-based ring signatures and Merkle hash tree techniques, we present a new efficient anonymous authentication mechanism. The newly proposed mechanism not only achieves good security properties, including authentication, anonymity and confidentiality, but also has strong robustness and high efficiency.