Visible to the public Biblio

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2021-03-22
Fan, X., Zhang, F., Turamat, E., Tong, C., Wu, J. H., Wang, K..  2020.  Provenance-based Classification Policy based on Encrypted Search. 2020 2nd International Conference on Industrial Artificial Intelligence (IAI). :1–6.
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.
Kellogg, M., Schäf, M., Tasiran, S., Ernst, M. D..  2020.  Continuous Compliance. 2020 35th IEEE/ACM International Conference on Automated Software Engineering (ASE). :511–523.
Vendors who wish to provide software or services to large corporations and governments must often obtain numerous certificates of compliance. Each certificate asserts that the software satisfies a compliance regime, like SOC or the PCI DSS, to protect the privacy and security of sensitive data. The industry standard for obtaining a compliance certificate is an auditor manually auditing source code. This approach is expensive, error-prone, partial, and prone to regressions. We propose continuous compliance to guarantee that the codebase stays compliant on each code change using lightweight verification tools. Continuous compliance increases assurance and reduces costs. Continuous compliance is applicable to any source-code compliance requirement. To illustrate our approach, we built verification tools for five common audit controls related to data security: cryptographically unsafe algorithms must not be used, keys must be at least 256 bits long, credentials must not be hard-coded into program text, HTTPS must always be used instead of HTTP, and cloud data stores must not be world-readable. We evaluated our approach in three ways. (1) We applied our tools to over 5 million lines of open-source software. (2) We compared our tools to other publicly-available tools for detecting misuses of encryption on a previously-published benchmark, finding that only ours are suitable for continuous compliance. (3) We deployed a continuous compliance process at AWS, a large cloud-services company: we integrated verification tools into the compliance process (including auditors accepting their output as evidence) and ran them on over 68 million lines of code. Our tools and the data for the former two evaluations are publicly available.
shree, S. R., Chelvan, A. Chilambu, Rajesh, M..  2020.  Optimization of Secret Key using cuckoo Search Algorithm for ensuring data integrity in TPA. 2020 International Conference on Computer Communication and Informatics (ICCCI). :1–5.
Optimization plays an important role in many problems that expect the accurate output. Security of the data stored in remote servers purely based on secret key which is used for encryption and decryption purpose. Many secret key generation algorithms such as RSA, AES are available to generate the key. The key generated by such algorithms are need to be optimized to provide more security to your data from unauthorized users as well as from the third party auditors(TPA) who is going to verify our data for integrity purpose. In this paper a method to optimize the secret key by using cuckoo search algorithm (CSA) is proposed.
Wang, X., Chi, Y., Zhang, Y..  2020.  Traceable Ciphertext Policy Attribute-based Encryption Scheme with User Revocation for Cloud Storage. 2020 International Conference on Computer Engineering and Application (ICCEA). :91–95.
Ciphertext policy Attribute-based encryption (CPABE) plays an increasingly important role in the field of fine-grained access control for cloud storage. However, The exiting solution can not balance the issue of user identity tracking and user revocation. In this paper, we propose a CP-ABE scheme that supports association revocation and traceability. This scheme uses identity directory technology to realize single user revocation and associated user revocation, and the ciphertext re-encryption technology guarantees the forward security of revocation without updating the private key. In addition, we can accurately trace the identity of the user according to the decryption private key and effectively solve the problem of key abuse. This scheme is proved to be safe and traceable under the standard model, and can effectively control the computational and storage costs while maintaining functional advantages. It is suitable for the practical scenarios of tracking audit and user revocation.
Yogita, Gupta, N. Kumar.  2020.  Integrity Auditing with Attribute based ECMRSA Algorithm for Cloud Data Outsourcing. 2020 3rd International Conference on Intelligent Sustainable Systems (ICISS). :1284–1289.
Cloud computing is a vast area within which large amounts of data are exchanged through cloud services and has fully grown with its on-demand technology. Due to these versatile cloud services, sensitive data will be stored on cloud storage servers and it is also used to dynamically control a number of problems: security, privacy, data privacy, data sharing, and integrity across cloud servers. Moreover, the legitimacy and control of data access should be maintained in this extended environment. So, one of the most important concepts of cryptographic techniques in cloud computing environment is Attribute Based Encryption (ABE). In this research work, data auditing or integrity checking is considered as an area of concern for securing th cloud storage. In data auditing approach, an auditor inspects and verifies the data file integrity without having any knowledge about the content of file and sends the verification report to the data owner. In this research, Elliptical Curve Modified RSA (ECMRSA) is proposed along with Modified MD5 algorithm which is used for attribute-based cloud data integrity verification, in which data user or owner uploads their encrypted data files at cloud data server and send the auditing request to the Third-Party Auditor (TPA) for verification of their data files. The Third-Party Auditor (TPA) challenges the data server for ensuring the integrity of data files on behalf of the data owners. After verification of integrity of data file auditor sends the audit report to the owner. The proposed algorithm integrates the auditing scheme with public key encryption with homomorphic algorithm which generates digital signature or hash values of data files on encrypted files. The result analysis is performed on time complexity by evaluating encryption time, GenProof time and VerifyProof Time and achieved improvement in resolving time complexity as compared to existing techiques.
OGISO, S., Mohri, M., Shiraishi, Y..  2020.  Transparent Provable Data Possession Scheme for Cloud Storage. 2020 International Symposium on Networks, Computers and Communications (ISNCC). :1–5.
Provable Data Possession (PDP) is one of the data security techniques to make sure that the data stored in the cloud storage exists. In PDP, the integrity of the data stored in the cloud storage is probabilistically verified by the user or a third-party auditor. In the conventional PDP, the user creates the metadata used for audition. From the viewpoint of user convenience, it is desirable to be able to audit without operations other than uploading. In other words, the challenge is to provide a transparent PDP that verifies the integrity of files according to the general cloud storage system model so as not to add operations to users. We propose a scheme in which the cloud generates the metadata used during verification, and the user only uploads files. It is shown that the proposed scheme is resistant to the forgery of cloud proof and the acquisition of data by a third-party auditor.
Vimercati, S. de Capitani di, Foresti, S., Paraboschi, S., Samarati, P..  2020.  Enforcing Corporate Governance's Internal Controls and Audit in the Cloud. 2020 IEEE 13th International Conference on Cloud Computing (CLOUD). :453–461.
More and more organizations are today using the cloud for their business as a quite convenient alternative to in-house solutions for storing, processing, and managing data. Cloud-based solutions are then permeating almost all aspects of business organizations, resulting appealing also for functions that, already in-house, may result sensitive or security critical, and whose enforcement in the cloud requires then particular care. In this paper, we provide an approach for securely relying on cloud-based services for the enforcement of Internal Controls and Audit (ICA) functions for corporate governance. Our approach is based on the use of selective encryption and of tags to provide a level of self-protection to data and for enabling only authorized parties to access data and perform operations on them, providing privacy and integrity guarantees, as well as accountability and non-repudiation.
Singh, P., Saroj, S. K..  2020.  A Secure Data Dynamics and Public Auditing Scheme for Cloud Storage. 2020 6th International Conference on Advanced Computing and Communication Systems (ICACCS). :695–700.
Cloud computing is an evolving technology that provides data storage and highly fast computing services at a very low cost. All data stored in the cloud is handled by their cloud service providers or the caretaker of the cloud. The data owner is concerned about the authenticity and reliability of the data stored in the cloud as the data owners. Data can be misappropriated or altered by any unauthorized user or person. This paper desire to suggest a secure public auditing scheme applying third party auditors to authenticate the privacy, reliability, and integrity of data stored in the cloud. This proposed auditing scheme composes the use of the AES-256 algorithm for encryption, SHA-512 for integrity check and RSA-15360 for public-key encryption. And perform data dynamics operation which deals with mostly insertion, deletion, and, modification.
Xu, P., Chen, L., Jiang, Y., Sun, Q., Chen, H..  2020.  Research on Sensitivity Audit Scheme of Encrypted Data in Power Business. 2020 IEEE International Conference on Energy Internet (ICEI). :6–10.

With the rapid progress of informatization construction in power business, data resource has become the basic strategic resource of the power industry and innovative element in power production. The security protection of data in power business is particularly important in the informatization construction of power business. In order to implement data security protection, transparent encryption is one of the fifteen key technical standards in the Construction Guideline of the Standard Network Data Security System. However, data storage in the encrypted state is bound to affect the security audit of data to a certain extent. Based on this problem, this paper proposes a scheme to audit the sensitivity of the power business data under the protection of encryption to achieve an efficient sensitivity audit of ciphertext data with the premise of not revealing the decryption key or data information. Through a security demonstration, this paper fully proves that this solution is secure under the known plaintext attacks.

Kumar, A..  2020.  A Novel Privacy Preserving HMAC Algorithm Based on Homomorphic Encryption and Auditing for Cloud. 2020 Fourth International Conference on I-SMAC (IoT in Social, Mobile, Analytics and Cloud) (I-SMAC). :198–202.
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.
2020-01-21
Yu, Yang, Hou, Jing, Li, Huan.  2019.  Study on Continuous Internal Audit System Modeling and Application. Proceedings of the 2019 International Conference on Artificial Intelligence and Advanced Manufacturing. :1–6.
Under the information environment the development of Continuous internal audit business model is inevitable and it will generally become the mainstream model. Based on the understanding of internal audit development in enterprises, it's found that most of current internal audit systems stay at post audit as an auxiliary tool of internal auditors in the auditing process, which hastens the application of continuous internal audit. Emerging computer technology is combined in this paper to build an universal continuous internal audit model, which is divided into four phases, based on internal audit system. Finally, based on the tracking error of index fund, this paper makes an applied research on the framework of the established continuous internal audit system.
Xu, Lei, Yuan, Xingliang, Steinfeld, Ron, Wang, Cong, Xu, Chungen.  2019.  Multi-Writer Searchable Encryption: An LWE-Based Realization and Implementation. Proceedings of the 2019 ACM Asia Conference on Computer and Communications Security. :122–133.
Multi-Writer Searchable Encryption, also known as public-key encryption with keyword search(PEKS), serves a wide spectrum of data sharing applications. It allows users to search over encrypted data encrypted via different keys. However, most of the existing PEKS schemes are built on classic security assumptions, which are proven to be untenable to overcome the threats of quantum computers. To address the above problem, in this paper, we propose a lattice-based searchable encryption scheme from the learning with errors (LWE) hardness assumption. Specifically, we observe that the keys of each user in a basic scheme are composed of large-sized matrices and basis of the lattice. To reduce the complexity of key management, our scheme is designed to enable users to directly use their identity for data encryption. We present several optimization techniques for implementation to make our design nearly practical. For completeness, we conduct rigorous security, complexity, and parameter analysis on our scheme, and perform comprehensive evaluations at a commodity machine. With a scenario of 100 users, the cost of key generation for each user is 125s, and the cost of searching a document with 1000 keywords is 13.4ms.
Li, Yuan, Wang, Hongbing, Zhao, Yunlei.  2019.  Delegatable Order-Revealing Encryption. Proceedings of the 2019 ACM Asia Conference on Computer and Communications Security. :134–147.
Order-revealing encryption (ORE) is a basic cryptographic primitive for ciphertext comparisons based on the order relationship of plaintexts while maintaining the privacy of them. In the data era we are experiencing, cross-dataset transactions become ubiquitous in practice. However, almost all the previous ORE schemes can only support comparisons on ciphertexts from the same user, which does not meet the requirement for the multi-user environment. In this work, we introduce and design ORE schemes with delegation functionality, which is referred to as delegatable ORE (DORE). The "delegation" here is an authorization that allows for efficient ciphertext comparisons among different users. To the best of our knowledge, it is the first ORE that allows an user to delegate the comparison privilege for his ciphertexts, which also opens the door for future explorations. At the heart of the construction and analysis of DORE is a new building tool proposed in this work, named delegatable equality-revealing encoding (DERE), which might be of independent interest.
Koh, John S., Bellovin, Steven M., Nieh, Jason.  2019.  Why Joanie Can Encrypt: Easy Email Encryption with Easy Key Management. Proceedings of the Fourteenth EuroSys Conference 2019. :1–16.

Email privacy is of crucial importance. Existing email encryption approaches are comprehensive but seldom used due to their complexity and inconvenience. We take a new approach to simplify email encryption and improve its usability by implementing receiver-controlled encryption: newly received messages are transparently downloaded and encrypted to a locally-generated key; the original message is then replaced. To avoid the problem of moving a single private key between devices, we implement per-device key pairs: only public keys need be synchronized via a simple verification step. Compromising an email account or server only provides access to encrypted emails. We implemented this scheme on several platforms, showing it works with PGP and S/MIME, is compatible with widely used mail clients and email services including Gmail, has acceptable overhead, and that users consider it intuitive and easy to use.

Jurado, Mireya, Smith, Geoffrey.  2019.  Quantifying Information Leakage of Deterministic Encryption. Proceedings of the 2019 ACM SIGSAC Conference on Cloud Computing Security Workshop. :129–139.
In order to protect user data while maintaining application functionality, encrypted databases can use specialized cryptography such as property-revealing encryption, which allows a property of the underlying plaintext values to be computed from the ciphertext. One example is deterministic encryption which ensures that the same plaintext encrypted under the same key will produce the same ciphertext. This technology enables clients to make queries on sensitive data hosted in a cloud server and has considerable potential to protect data. However, the security implications of deterministic encryption are not well understood. We provide a leakage analysis of deterministic encryption through the application of the framework of quantitative information flow. A key insight from this framework is that there is no single "right'' measure by which leakage can be quantified: information flow depends on the operational scenario and different operational scenarios require different leakage measures. We evaluate leakage under three operational scenarios, modeled using three different gain functions, under a variety of prior distributions in order to bring clarity to this problem.
Alexandru, Andreea B., Pappas, George J..  2019.  Encrypted LQG Using Labeled Homomorphic Encryption. Proceedings of the 10th ACM/IEEE International Conference on Cyber-Physical Systems. :129–140.
We consider the problem of implementing a Linear Quadratic Gaussian (LQG) controller on a distributed system, while maintaining the privacy of the measurements, state estimates, control inputs and system model. The component sub-systems and actuator outsource the LQG computation to a cloud controller and encrypt their signals and matrices. The encryption scheme used is Labeled Homomorphic Encryption, which supports the evaluation of degree-2 polynomials on encrypted data, by attaching a unique label to each piece of data and using the fact that the outsourced computation is known by the actuator. We write the state estimate update and control computation as multivariate polynomials in the encrypted data and propose an extension to the Labeled Homomorphic Encryption scheme that achieves the evaluation of low-degree polynomials on encrypted data, with degree larger than two. We showcase the numerical results of the proposed protocol for a temperature control application that indicates competitive online times.
2020-01-20
Nguyen-Van, Thanh, Le, Tien-Dat, Nguyen-Anh, Tuan, Nguyen-Ho, Minh-Phuoc, Nguyen-Van, Tuong, Le-Tran, Minh-Quoc, Le, Quang Nhat, Pham, Harry, Nguyen-An, Khuong.  2019.  A System for Scalable Decentralized Random Number Generation. 2019 IEEE 23rd International Enterprise Distributed Object Computing Workshop (EDOCW). :100–103.

Generating public randomness has been significantly demanding and also challenging, especially after the introduction of the Blockchain Technology. Lotteries, smart contracts, and random audits are examples where the reliability of the randomness source is a vital factor. We demonstrate a system of random number generation service for generating fair, tamper-resistant, and verifiable random numbers. Our protocol together with this system is an R&D project aiming at providing a decentralized solution to random number generation by leveraging the blockchain technology along with long-lasting cryptographic primitives including homomorphic encryption, verifiable random functions. The system decentralizes the process of generating random numbers by combining each party's favored value to obtain the final random numbers. Our novel idea is to force each party to encrypt his contribution before making it public. With the help of homomorphic encryption, all encrypted contribution can be combined without performing any decryption. The solution has achieved the properties of unpredictability, tamper-resistance, and public-verifiability. In addition, it only offers a linear overall complexity with respect to the number of parties on the network, which permits great scalability.

Gollamudi, Anitha, Chong, Stephen, Arden, Owen.  2019.  Information Flow Control for Distributed Trusted Execution Environments. 2019 IEEE 32nd Computer Security Foundations Symposium (CSF). :304–30414.

Distributed applications cannot assume that their security policies will be enforced on untrusted hosts. Trusted execution environments (TEEs) combined with cryptographic mechanisms enable execution of known code on an untrusted host and the exchange of confidential and authenticated messages with it. TEEs do not, however, establish the trustworthiness of code executing in a TEE. Thus, developing secure applications using TEEs requires specialized expertise and careful auditing. This paper presents DFLATE, a core security calculus for distributed applications with TEEs. DFLATE offers high-level abstractions that reflect both the guarantees and limitations of the underlying security mechanisms they are based on. The accuracy of these abstractions is exhibited by asymmetry between confidentiality and integrity in our formal results: DFLATE enforces a strong form of noninterference for confidentiality, but only a weak form for integrity. This reflects the asymmetry of the security guarantees of a TEE: a malicious host cannot access secrets in the TEE or modify its contents, but they can suppress or manipulate the sequence of its inputs and outputs. Therefore DFLATE cannot protect against the suppression of high-integrity messages, but when these messages are delivered, their contents cannot have been influenced by an attacker.

Sui, Zhiyuan, de Meer, Hermann.  2019.  BAP: A Batch and Auditable Privacy Preservation Scheme for Demand-Response in Smart Grids. IEEE Transactions on Industrial Informatics. :1–1.
Advancing network technologies allows the setup of two-way communication links between energy providers and consumers. These developing technologies aim to enhance grid reliability and energy efficiency in smart grids. To achieve this goal, energy usage reports from consumers are required to be both trustworthy and confidential. In this paper, we construct a new data aggregation scheme in smart grids based on a homomorphic encryption algorithm. In the constructed scheme, obedient consumers who follow the instruction can prove its ajustment using a range proof protocol. Additionally, we propose a new identity-based signature algorithm in order to ensure authentication and integrity of the constructed scheme. By using this signature algorithm, usage reports are verified in real time. Extensive simulations demonstrate that our scheme outperforms other data aggregation schemes.
Liu, Donglan, Zhang, Hao, Wang, Wenting, Zhao, Yang, Zhao, Xiaohong, Yu, Hao, Lv, Guodong, Zhao, Yong.  2019.  Research on Protection for the Database Security Based on the Cloud of Smart Grid. 2019 IEEE 11th International Conference on Communication Software and Networks (ICCSN). :585–589.

As cloud services enter the Internet market, cloud security issues are gradually exposed. In the era of knowledge economy, the unique potential value of big data is being gradually explored. However, the control of data security is facing many challenges. According to the development status and characteristics of database within the cloud environment, this paper preliminary studies on the database security risks faced by the “three-clouds” of State Grid Corporation of China. Based on the mature standardization of information security, this paper deeply studies the database security requirements of cloud environment, and six-step method for cloud database protection is presented, which plays an important role in promoting development of security work for the cloud database. Four key technologies of cloud database security protection are introduced, including database firewall technology, sensitive data encryption, production data desensitization, and database security audit technology. It is helpful to the technology popularization of the grade protection in the security of the cloud database, and plays a great role in the construction of the security of the state grid.

De Capitani di Vimercati, Sabrina, Foresti, Sara, Livraga, Giovanni, Samarati, Pierangela.  2019.  Empowering Owners with Control in Digital Data Markets. 2019 IEEE 12th International Conference on Cloud Computing (CLOUD). :321–328.

We propose an approach for allowing data owners to trade their data in digital data market scenarios, while keeping control over them. Our solution is based on a combination of selective encryption and smart contracts deployed on a blockchain, and ensures that only authorized users who paid an agreed amount can access a data item. We propose a safe interaction protocol for regulating the interplay between a data owner and subjects wishing to purchase (a subset of) her data, and an audit process for counteracting possible misbehaviors by any of the interacting parties. Our solution aims to make a step towards the realization of data market platforms where owners can benefit from trading their data while maintaining control.

Zhu, Yan, Zhang, Yi, Wang, Jing, Song, Weijing, Chu, Cheng-Chung, Liu, Guowei.  2019.  From Data-Driven to Intelligent-Driven: Technology Evolution of Network Security in Big Data Era. 2019 IEEE 43rd Annual Computer Software and Applications Conference (COMPSAC). 2:103–109.

With the advent of the big data era, information systems have exhibited some new features, including boundary obfuscation, system virtualization, unstructured and diversification of data types, and low coupling among function and data. These features not only lead to a big difference between big data technology (DT) and information technology (IT), but also promote the upgrading and evolution of network security technology. In response to these changes, in this paper we compare the characteristics between IT era and DT era, and then propose four DT security principles: privacy, integrity, traceability, and controllability, as well as active and dynamic defense strategy based on "propagation prediction, audit prediction, dynamic management and control". We further discuss the security challenges faced by DT and the corresponding assurance strategies. On this basis, the big data security technologies can be divided into four levels: elimination, continuation, improvement, and innovation. These technologies are analyzed, combed and explained according to six categories: access control, identification and authentication, data encryption, data privacy, intrusion prevention, security audit and disaster recovery. The results will support the evolution of security technologies in the DT era, the construction of big data platforms, the designation of security assurance strategies, and security technology choices suitable for big data.

Wang, Ti, Ma, Hui, Zhou, Yongbin, Zhang, Rui, Song, Zishuai.  2019.  Fully Accountable Data Sharing for Pay-As-You-Go Cloud Scenes. IEEE Transactions on Dependable and Secure Computing. :1–1.
Many enterprises and individuals prefer to outsource data to public cloud via various pricing approaches. One of the most widely-used approaches is the pay-as-you-go model, where the data owner hires public cloud to share data with data consumers, and only pays for the actually consumed services. To realize controllable and secure data sharing, ciphertext-policy attribute-based encryption (CP-ABE) is a suitable solution, which can provide fine-grained access control and encryption functionalities simultaneously. But there are some serious challenges when applying CP-ABE in pay-as-you-go. Firstly, the decryption cost in ABE is too heavy for data consumers. Secondly, ABE ciphertexts probably suffer distributed denial of services (DDoS) attacks, but there is no solution that can eliminate the security risk. At last, the data owner should audit resource consumption to guarantee the transparency of charge, while the existing method is inefficient. In this work, we propose a general construction named fully accountable ABE (FA-ABE), which simultaneously solves all the challenges by supporting all-sided accountability in the pay-as-you-go model. We formally define the security model and prove the security in the standard model. Also, we implement an instantiate construction with the self-developed library libabe. The experiment results indicate the efficiency and practicality of our construction.
Oqaily, Momen, Jarraya, Yosr, Mohammady, Meisam, Majumdar, Suryadipta, Pourzandi, Makan, Wang, Lingyu, Debbabi, Mourad.  2019.  SegGuard: Segmentation-based Anonymization of Network Data in Clouds for Privacy-Preserving Security Auditing. IEEE Transactions on Dependable and Secure Computing. :1–1.
Security auditing allows cloud tenants to verify the compliance of cloud infrastructure with respect to desirable security properties, e.g., whether a tenant's virtual network is properly isolated from other tenants' networks. However, the input to such an auditing task, such as the detailed topology of the underlying cloud infrastructure, typically contains sensitive information which a cloud provider may be reluctant to hand over to a third party auditor. Additionally, auditing results intended for one tenant may inadvertently reveal private information about other tenants, e.g., another tenant's VM is reachable due to a misconfiguration. How to anonymize both the input data and the auditing results in order to prevent such information leakage is a novel challenge that has received little attention. Directly applying most of the existing anonymization techniques to such a context would either lead to insufficient protection or render the data unsuitable for auditing. In this paper, we propose SegGuard, a novel anonymization approach that prevents cross-tenant information leakage through per-tenant encryption, and prevents information leakage to auditors through hiding real input segments among fake ones; in addition, applying property-preserving encryption in an innovative way enables SegGuard to preserve the data utility for auditing while mitigating semantic attacks. We implement SegGuard based on OpenStack, and evaluate its effectiveness and overhead using both synthetic and real data. Our experimental results demonstrate that SegGuard can reduce the information leakage to a negligible level (e.g., less than 1% for an adversary with 50% pre-knowledge) with a practical response time (e.g., 62 seconds to anonymize a cloud infrastructure with 25,000 virtual machines).
2019-08-05
Grubbs, Paul, Lacharite, Marie-Sarah, Minaud, Brice, Paterson, Kenneth G..  2018.  Pump Up the Volume: Practical Database Reconstruction from Volume Leakage on Range Queries. Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security. :315-331.

We present attacks that use only the volume of responses to range queries to reconstruct databases. Our focus is on practical attacks that work for large-scale databases with many values and records, without requiring assumptions on the data or query distributions. Our work improves on the previous state-of-the-art due to Kellaris et al. (CCS 2016) in all of these dimensions. Our main attack targets reconstruction of database counts and involves a novel graph-theoretic approach. It generally succeeds when R , the number of records, exceeds \$N2/2\$, where N is the number of possible values in the database. For a uniform query distribution, we show that it requires volume leakage from only O(N2 łog N) queries (cf. O(N4łog N) in prior work). We present two ancillary attacks. The first identifies the value of a new item added to a database using the volume leakage from fresh queries, in the setting where the adversary knows or has previously recovered the database counts. The second shows how to efficiently recover the ranges involved in queries in an online fashion, given an auxiliary distribution describing the database. Our attacks are all backed with mathematical analyses and extensive simulations using real data.