Rupeng Yang

Towards leakage-resilient fine-grained access control in fog computing

Fog Computing, a technology that takes advantage of both the paradigms of Cloud Computing and the Internet of Things, has a great advantage in reducing the communication cost. Since its introduction, fog computing has found a lot of applications, including, for instance, connected vehicles, wireless sensors, smart cities and etc. One prominent problem in fog computing is how fine-grained access control can be imposed. Functional encryption, a new cryptographic primitive, is known to support fine-grained access control. However, when it comes to some new threats in the fog computing scenario, such as side channel attacks, functional encryption cannot maintain its security. Therefore, we need new cryptographic primitives that not only provide a way to securely share data with a fine-grained access control but also are able to resist those new threats.In this paper, we consider how to construct functional encryption schemes (FEs) adaptively secure in continual memory leakage model (CML), which is one of the strongest models that allows continuous leakage on both user and master secret keys. Besides providing privacy and fine-grained access control in fog computing, our scheme can also guarantee security against side channel attacks. More concretely, we propose a generic framework for constructing fully secure leakage-resilient FEs (LR-FEs) in the CML model results from leakage-resilient pair encoding, which is an extension of pair encoding presented in the recent work of Attrapadung. In this way, our framework simplifies the design and analysis of LR-FEs into the design and analysis of predicate encodings. Moreover, we discover new adaptively secure LR-FEs, including FE for regular languages, attribute-based encryption (ABE) for large universe and ABE with short ciphertext. Above all, leakage-resilient adaptively secure functional encryption schemes can equip fog computing with higher security and fine-grained access control. Provide access control in fog computing secure against side-channel attacks.Develop a generic framework of leakage-resilient functional encryptions, a basic tool.Present many new fully secure leakage-resilient functional encryptions.

Public-key encryption with keyword search secure against continual memory attacks

Continual memory attacks, inspired by recent realistic physical attacks, have broken many cryptographic schemes that were considered secure in traditional cryptography model. In this paper, we consider the continual memory leakage resilience in public-key encryption with keyword search scheme (PEKS). We give the definition of continual memory leakage resilience security for PEKS, which allows continual secret key leakage in the trapdoor generation algorithm rather than leakage of trapdoor itself. We believe that the definition is more suitable for practical PEKS scenario. To construct a concrete PEKS scheme secure against continual memory attacks, we firstly obtain a continual master-key leakage-resilient anonymous identity-based encryption (IBE) scheme by applying the generic tool provided by Lewko et al. to a fully secure anonymous IBE scheme that comes from the fully secure anonymous hierarchical identity-based encryption (HIBE) scheme of De Caro and colleagues. Then, we transform our continual master-key leakage-resilient anonymous IBE scheme to a PEKS scheme using the generic Anonymous IBE-to-PEKS transformation and prove its continual leakage-resilient security. Copyright

Unforgeable Watermarking Schemes with Public Extraction

A watermarking scheme consists of a marking algorithm allowing one to embed some information into a program while preserving its functionality and an extraction algorithm enabling one to extract embedded information from a marked program. The main security properties of watermarking schemes include unremovability and unforgeability. However, all current watermarking schemes achieving both properties simultaneously require the extraction algorithm to access either the marking secret key or the latest state maintained by the marking algorithm. As a result, to extract information embedded in a marked program, one must communicate with a third party. This greatly limits the applicability of current watermarking schemes. In this paper, we solve this problem by presenting the first (stateless) publicly extractable watermarking scheme with unremovability and unforgeability.

Achieving Flexibility for ABE with Outsourcing via Proxy Re-Encryption

Outsourcing the decryption of attribute-based encryption (ABE) ciphertext is a promising way to tackle the question of how users can perform decryption efficiently. However, existing solutions require the type of the target ciphertext to be determined at the setup of the outsourcing scheme. As such, making the target cryptosystems (or the clients) to be versatile becomes an issue that warrants investigations. In this paper, the problem we wish to tackle is to transform an ABE ciphertext to any client who is using the same, or possibly different, public-key encryption (PKE) system with the sender. The problem is of practical interest since it is hard to require all clients to use the same PKE, especially in the case of remote and cross-system data sharing. In addition, we also consider whether robust client-side decryption scheme can be adopted. This feature is not supported in the existing ABE with outsourcing. We introduce cross-system proxy re-encryptions (CS-PRE), a new re-encryption paradigm in which a semi-trusted proxy converts a ciphertext of a source cryptosystem (

Lattice-Based Universal Accumulator with Nonmembership Arguments.

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Decentralized Blacklistable Anonymous Credentials with Reputation

) into a ciphertext for a target cryptosystem (

Practical Range Proof for Cryptocurrency Monero with Provable Security

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Position based cryptography with location privacy

). We formalize CS-PRE and present a construction that performs well in the following aspects. (1)Versatility:

Updatable Hash Proof System and Its Applications

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Leakage-Resilient Functional Encryption via Pair Encodings

can be any attribute-based encryption (ABE) within Attrapadungs pair encoding framework.