The side channel attacks will lead to the destruction of the security of the traditional cryptographic scheme. Leakage-resilient identity-based signature has attracted great attention. Based on the dual system encryption technology, we construct an identity-based signature scheme that can resist continuous private key leakage. In the standard model, the security of the scheme is proved. The key points of our leakage-resilient signature scheme are as follows: (1) The private key can be extended according to the security requirements. In other words, when the leakage is serious, we can select a bigger value n, where n is a parameter related to the leakage rate. (2) An elaborate key update algorithm makes the scheme resist continuous leakage attacks. Furthermore, the updated private key has the same distribution as the previous private key. (3) The proposed scheme is fully secure in the standard model rather than in the random oracle model or in the general group model. In order to achieve this goal, we use dual system encryption technology. Thus, the security of the constructed scheme does not depend on the number of queries of the attacker.

/pdf/fully-secure-id-based-signature-scheme-with-continuous-21icbumg.pdf

Fully Secure ID-Based Signature Scheme with Continuous Leakage Resilience

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%.

/pdf/pairing-free-for-public-key-encryption-with-equality-test-38kjnggfwa.pdf

Pairing-Free for Public Key Encryption With Equality Test Scheme

Identity-based encryption with leakage-amplified chosen-ciphertext attacks security

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

A generic construction of CCA-secure deterministic encryption

Leakage of private information has become a threat to the security of computing systems. It has become a common security requirement that a cryptography scheme should withstand various leakage attacks, even the continuous leakage attacks. However, in the current constructions on the (continuous) leakage-resilient identity-based encryption (CLR-IBE) scheme, the leakage parameter is a fixed value. Aiming to solve these problems, in this study, the authors show how to construct the CLR-IBE scheme, and the adaptive chosen-ciphertext attacks security of proposed construction can be proved in the standard model. To further improve the practicability of CLR-IBE scheme, they design an improved IBE scheme with continuous leakage amplified property, and the leakage parameter has an arbitrary length.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-ifs.2018.5203

Xin Wang

Papers

A generic construction of CCA-secure deterministic encryption

Identity-based encryption resilient to continuous key leakage