Hedged PKE schemes are designed to provide useful security when the per-message randomness fails to be uniform, say, due to faulty implementations or adversarial actions. A simple and elegant theoretical approach to building such schemes works like this: Synthesize fresh random bits by hashing all of the encryption inputs, and use the resulting hash output as randomness for an underlying PKE scheme.

Hedging Public-Key Encryption in the Real World.

The modular exponentiation has been proved better in terms of computational efficiency as compared to bilinear pairing. Therefore, discrete logarithm, a concept of modular exponentiation may be incorporated to present improved security schemes. With this aim, an efficient public key encryption scheme with equality test (PKEwET) is proposed in this paper. Unlike the most of existing bilinear pairing based PKEwET schemes, the presented scheme employs discrete logarithm to improve the computational efficiency. Moreover, we introduce the verification process during the test phase to validate the ciphertext and to improve the security comparative to the prevalent schemes. The performance analysis depicts that the proposed scheme is quite efficient and more practical than the existing PKEwET schemes. More precisely, compared to Lin et al. ’s scheme, the time cost has been reduced by at least 39% for the decryption process. Furthermore, for the type-3 test phase, the time cost has been reduced by at least 68%.

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Pairing-Free for Public Key Encryption With Equality Test Scheme

Identity-based encryption (IBE) is a new public key encryption system, any string can be its public key, private key is generated by the private key generator that owns the main private key. Hierarchical identity-based encryption (HIBE) is an extension of IBE, which can lighten the burden of the center of private-key generation greatly. HIBE is more suitable for the protection of large organizations and distributed environments, and it can isolate damage when some a private key is disclosed. In this paper, a more secure and efficient HIBE scheme from lattice is presented. First, we propose a chosen-plaintext attacks (CPA) secure HIBE scheme from the learning with errors over rings (R-LWE), on this basis, a new HIBE scheme that is secure against adaptive chosen-ciphertext attacks (CCA) is constructed, whose security is based on the hardness of the shortest vector problem (SVP). Analyses indicate the proposed scheme is more efficient than correlative cryptosystems and CCA-secure in the random oracle model.

Chosen-ciphertext Secure Hierarchical Identity-based Encryption from R-LWE

Public key encryption with equality test enables the user to determine whether two ciphertexts contain the same information without decryption. Therefore, it may serve as promising cryptographic technique for cloud-assisted wireless sensor networks (CWSNs) to maintain data privacy. In this paper, an efficient RSA with equality test algorithm is proposed. The presented scheme also handles the attackers based on their authorization ability. Precisely, the proposed scheme is proved to be one-way against chosen-ciphertext attack security and indistinguishable against chosen ciphertext attacks. Moreover, the experimental evaluations depict that the underlying scheme is efficient in terms of encryption, decryption, and equality testing. Thus, this scheme may be used as a practical solution in context of CWSNs, where the users may compare two ciphertexts without decryption.

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New constructions of equality test scheme for cloud-assisted wireless sensor networks.

Dual projective hashing is an extension of Cramer-Shoup projective hashing, which implies lossy trapdoor functions (LTDFs) and deterministic PKE schemes secure with respect to hard-to-invert auxiliary input. In this paper, we introduce the notion of updatable all-but-one dual projective hashing (UDPH) based on the all-but-one variant of dual projective hashing, which allows us to investigate the continuous leakage of invisible key update in the same context. In particular,


we give a general construction of leakage-resilient all-but-one LTDFs via UDPH, which yields high efficiency compared with existed direct leakage-resilient all-but-one LTDFs constructions based on MDDH and SXDH. Concretely, our generic framework can be instantiated with k-LIN, DCR, QR and LWE assumptions in the standard model.


we present a modular framework for leakage-resilient deterministic PKEs with hard-to-invert auxiliary input, which is proven secure under the introduced continuous-leakage-resilient strong privacy indistinguishability-based security model of invisible key update. Compared with the known MDDH/SXDH-based schemes, our constructions can be instantiated with more widely-accepted assumptions including k-LIN, DCR, QR and LWE.

Meijuan Huang

Papers

A generic construction of CCA-secure deterministic encryption

Public-key encryption scheme with optimal continuous leakage resilience

Constructing totally disjoint spectra plateaued functions and searching five-value spectrum functions in odd variables

Constructions of non-basic totally disjoint spectra plateaued functions for cryptographic applications