Efficient and Provably Secure Multi-Recipient Signcryption from Bilinear Pairings

Signcryption is a cryptographic primitive that performs signature and encryption simultaneously, at lower computational costs and communication overheads than the signature-then- encryption approach. In this paper, we propose an efficient multi-recipient signcryption scheme based on the bilinear pairings, which broadcasts a message to multiple users in a secure and authenticated manner. We prove its semantic security and unforgeability under the Gap Diffie-Hellman problem assumption in the random oracle model. The proposed scheme is more efficient than re-signcrypting a message n times using a signcryption scheme in terms of computational costs and communication overheads.

Provably Secure General Aggregate Signcryption Scheme in the Random Oracle Model

To reduce the size of certificate chains and the ciphertext size in secure routing protocols, a General Aggregate Signcryption Scheme (GASC) is presented. In GASC, an identity-based signcryption algorithm and an aggregate signature algorithm are combined in a practical and secure manner to form the general aggregate signcryption scheme's schema and concept, and a new secure, efficiently general aggregate signcryption scheme, which allows the aggregation of n distinct signcryptions by n distinct users on n distinct messages, is proposed. First, the correction of the GASC scheme is analyzed. Then, we formally prove the security of GASC in the random oracle models IND-CCA2 and EUF-CMA under the DBDHP assumption and the DLP assumption, respectively. The results show that the GASC scheme is not only secure against any probabilistic polynomial-time IND-GASC-CCA2 and EUF-GASC-CMA adversary in the random oracle models but also efficient in pairing ê computations. In addition, the GASC scheme gives an effective remedy to the key escrow problem, which is an inherent issue in IBC by splitting the private key into two parts, and reduces the communication complexity by eliminating the interaction among the senders (signers) before the signcryption generation.

A Secure Signcryption Scheme for Electronic Health Records Sharing in Blockchain

In the existing Electronic Health Records(EHRs),the medical information of patients is completely controlled by various medical institutions.As such,patients have no dominant power over their own EHRs.These personal data are not only inconvenient to access and share,but are also prone to cause privacy disclosure.The blockchain technology provides a new development direction in the medical field.Blockchain-based EHRs are characterized by decentralization,openness and non-tampering of records,which enable patients to better manage their own EHRs.In order to better protect the privacy of patients,only designated receivers can access EHRs,and receivers can authenticate the sharer to ensure that the EHRs are real and effective.In this study,we propose an identity-based signcryption scheme with multiple authorities for multiple receivers,which can resist N-1 collusion attacks among N authorities.In addition,the identity information of receivers is anonymous,so the relationship between them and the sharer is not disclosed.Under the random oracle model,it was proved that our scheme was secure and met the unforgeability and confidentiality requirements of signcryption.Moreover,we evaluated the performance of the scheme and found that it had the moderate signcryption efficiency and excellent signcryption attributes.

Identity-based searchable attribute signcryption in lattice for a blockchain-based medical system

Electronic healthcare systems can offer convenience but face the risk of data forgery and information leakage.To solve these issues,we propose an identity-based searchable attribute signcryption in lattice for a blockchain-based medical system(BCMS-LIDSASC).BCMS-LIDSASC achieves decentralization and anti-quantum security in the blockchain environment,and provides fine-grained access control and searchability.Furthermore,smart contracts are used to replace traditional trusted third parties,and the interplanetary file system(IPFS)is used for ciphertext storage to alleviate storage pressure on the blockchain.Compared to other schemes,BCMS-LIDSASC requires smaller key size and less storage,and has lower computation cost.It contributes to secure and efficient management of medical data and can protect patient privacy and ensure the integrity of electronic healthcare systems.

An Efficient Identity-Based Anonymous Signcryption Scheme

Signcryption is a cryptographic primitive that performs encryption and signature in a single logical step more efficiently than sign-then-encrypt approach. Till now, various kinds of signcryption schemes have been proposed. Among them, the requirement of signcrypter＇s privacy protection is needful in some practical applications. In this paper, a new identity-based anonymous signcryption scheme from hilinear pairings, which is the organic combination of identity-based ring signature and encryption scheme, is proposed. The proposed scheme is indistinguishable against the chosen ciphertext attack under the Decisional Bilinear Diffie-Hellman assumption in the random oracle model. Its unforgeability relies on the computational Diffieellman problem. Compared with the previous schemes, the new scheme is more efficient in computation.

Identity-based aggregate signcryption in the standard model from multilinear maps

Signcryption is a public key cryptographic method that achieves unforgeability and confidentiality simultaneously with significantly smaller overhead than that required by ＂digital signature followed by public key encryption＂. It does this by signing and encr.ypting a message in a single step. An aggregate signcryption scheme allows individual signcryption ciphertexts intended for the same recipi- ent to be aggregated into a single （shorter） combined ciphertext without losing any of the security guarantees. We present an aggregate signcryption scheme in the identity-based setting using multilinear maps, and provide a proof of security in the standard model. To the best of our knowledge, our new scheme is the first aggregate signcryption scheme that is secure in the standard model.

Analysis and Improvement of Authenticatable Ring Signcryption Scheme

We show that the Zhang-Yang-Zhu-Zhang identity-based authenticatable ring signcryption scheme is not secure against chosen plaintext attacks.Furthermore, we propose an improved scheme that remedies the weakness of the Zhang-Yang-Zhu-Zhang scheme.The improved scheme has shorter ciphertext size than the Zhang-Yang-Zhu-Zhang scheme.We then prove that the improved scheme satisfies confidentiality, unforgeability, anonymity and authenticatability.

A Secure NDN Framework for Internet of Things Enabled Healthcare

Healthcare is a binding domain for the Internet of Things(IoT)to automate healthcare services for sharing and accumulation patient records at anytime from anywhere through the Internet.The current IP-based Internet architecture suffers from latency,mobility,location dependency,and security.The Named Data Networking(NDN)has been projected as a future internet architecture to cope with the limitations of IP-based Internet.However,the NDN infrastructure does not have a secure framework for IoT healthcare information.In this paper,we proposed a secure NDN framework for IoTenabled Healthcare(IoTEH).In the proposed work,we adopt the services of Identity-Based Signcryption(IBS)cryptography under the security hardness Hyperelliptic Curve Cryptosystem(HCC)to secure the IoTEH information in NDN.The HCC provides the corresponding level of security using minimal computational and communicational resources as compared to bilinear pairing and Elliptic Curve Cryptosystem(ECC).For the efficiency of the proposed scheme,we simulated the security of the proposed solution using Automated Validation of Internet Security Protocols and Applications(AVISPA).Besides,we deployed the proposed scheme on the IoTEH in NDN infrastructure and compared it with the recent IBS schemes in terms of computation and communication overheads.The simulation results showed the superiority and improvement of the proposed framework against contemporary related works.

A Confidential Non-Interactive Origin-Guarantee Message Transfer Scheme with Uniqueness

A biometric identity-based signcryption scheme is presented, which combines signature and encryption. In the proposed scheme, biometric information is used to construct the private key to ensure uniqueness, and a user＇s identity is the corresponding public key to make the message transfer non-interactive. The proposed scheme is shown to provide confidentiality and unforgeability in the random oracle model