Memory attacks, inspired by recent realistic physical attacks, have broken many cryptographic schemes which were considered secure. In this paper, we consider the memory leakage resilience in anonymous identity-based encryption schemes. We construct a leakage-resilient anonymous identity based encryption scheme based on dual system encryption. Inspired by Lewko et al.'s techniques, our scheme is built in composite order groups which have four prime order subgroups and blind the public parameters and cipher texts using the random elements of same subgroup to achieve the anonymity. Moreover, we analyze the security of our scheme in the full adaptive-ID model rather than the selective-ID model.
Memory attacks, inspired by recent realistic physical attacks, have broken many cryptographic schemes which were considered secure. In this paper, we consider the memory leakage resilience in anonymous identity-based encryption schemes. We construct a leakage-resilient anonymous identity based encryption scheme based on dual system encryption. Inspired by Lewko et al.'s techniques, our scheme is built in composite order groups which have four prime order subgroups and blind the public parameters and cipher texts using the random elements of same subgroup to achieve the anonymity. Moreover, we analyze the security of our scheme in the full adaptive-ID model rather than the selective-ID model.
Hierarchical identity-based encryption can be used to protect the sensitive data in cloud system. However, as the traditional security model does not capture side-channel attacks, many hierarchical identity-based encryption schemes do not resist this kind of attack, which can exploit various forms of unintended information leakage. Inspired by these, leakage-resilience cryptography formalises some models of side-channel attacks. In this paper, we consider the memory leakage resilience in anonymous hierarchical identity-based encryption schemes. By applying Lewko et al.'s tools, we construct a master key leakage-resilient anonymous hierarchical identity-based encryption scheme based on dual system encryption techniques. As an interesting application of our scheme, we consider security for public-key encryption with multi-keyword ranked search (PEMKRS) in the presence of secret key leakage in the trapdoor generation algorithm, and provide a generic construction of leakage-resilient secure PEMKRS from a master key leakage-resilient anonymous hierarchical identity-based encryption scheme.
Hierarchical identity-based encryption can be used to protect the sensitive data in cloud system. However, as the traditional security model does not capture side-channel attacks, many hierarchical identity-based encryption schemes do not resist this kind of attack, which can exploit various forms of unintended information leakage. Inspired by these, leakage-resilience cryptography formalises some models of side-channel attacks. In this paper, we consider the memory leakage resilience in anonymous hierarchical identity-based encryption schemes. By applying Lewko et al.'s tools, we construct a master key leakage-resilient anonymous hierarchical identity-based encryption scheme based on dual system encryption techniques. As an interesting application of our scheme, we consider security for public-key encryption with multi-keyword ranked search (PEMKRS) in the presence of secret key leakage in the trapdoor generation algorithm, and provide a generic construction of leakage-resilient secure PEMKRS from a master key leakage-resilient anonymous hierarchical identity-based encryption scheme.
With the purpose of taking physical attacks into account in security proofs, leakage-resilient cryptography has been initiated. Recently, many leakage-resilient cryptographic primitives have been proposed. In this paper, we put forward the first leakage-resilient wicked identity-based encryption (wicked IBE) scheme. To achieve this goal, we first present a new wicked IBE scheme in the composite order groups. The security proof of this scheme is achieved via the dual system encryption technique. In contrast with existing wicked IBE schemes, the new proposal can be proved fully secure in the standard model, even when the maximum hierarchy depth is a polynomial in the security parameter. Moreover, its security is based on some standard assumptions in the composite groups, which are independent of the hierarchy depth of the scheme. Based on this newly proposed scheme, we then put forward a fully secure leakage-resilient wicked IBE scheme in the bounded memory-leakage model. The leakage here is not only allowed on the user's secret key, but also on the master secret key. Its security is proved in the standard model by a hybrid argument in a sequence of computationally indistinguishable games. To the best of our knowledge, this is the first wicked IBE scheme in the context of leakage resilience.
Identity-based encryption (IBE) has many appealing applications. However, some traditional IBE schemes may not be secure in the real world due to the side-channel attacks. Leakage-resilient cryptography can capture these attacks by modeling information leakage that adversary can access. In this paper, we apply a hash proof technique in the existing CCA-secure variant of the Gentry's IBE scheme to construct a new leakage-resilient IBE scheme in the bounded-leakage model. The proposed scheme is more computationally efficient than the original Alwen et al. 's leakage-resilient IBE scheme. It enjoys a shorter key (public/secret key) length, and a higher relative key leakage ratio. The new leakage-resilient scheme is proved semantically secure against adaptive chosen ciphertext attack in the standard model under the truncated augmented bilinear Diffie-Hellman exponent ( |q| -TABDHE) assumption.
An anonymous identity based encryption (anonymous IBE) scheme requires that an adversary can not determine the identity of the recipient from a ciphertext encrypted by the corresponding public key. The anonymity was formalized in previous works [1], [13], and this can be considered under chosen plaintext attack and adaptive chosen ciphertext attack, yielding two notions of security, ID-II-CPA and ID-II-CCA, where II denotes “indistinguishability of identities.” However, how to obtain an ID-II-CCA secure anonymous IBE in the random oracle model is still a challenging problem. We firstly propose a new notion of plaintext awareness in the two identities setting, called PATI. Secondly, we prove that the IBE scheme is ID-II-CCA secure if it is PATI secure. Finally, we propose the first generic conversion for anonymous IBE from ID-II-CPA to ID-II-CCA in the random oracle model.
Abstract In the actual applications, an adversary can break the security of cryptography scheme through various leakage attacks (e.g. side-channel attacks, cold-boot attacks, etc.), even the continuous leakage attacks. That is, a practical cryptography scheme must maintain its claimed security in the continuous leakage setting. However, the previous constructions on the leakage-resilient identity-based encryption (IBE) scheme could tolerate a leakage that is bounded, and cannot resist the continuous leakage attacks. In order to further achieve the better security, a novel method to build the continuous leakage-resilient IBE scheme with tight security is presented in this paper, and the scheme’s security is proved, in the standard model, based on a stronger security assumption that depends on the number of queries made by the adversary. In addition, our proposal has several advantages over previous such constructions, e.g. shorter public parameters, higher communication efficiency, tight security, etc.