A New Identity-Based Encryption Scheme with Accountable Authority Based on SM9

Accountable authority identity-based encryption (A-IBE) is an extension of identity-based encryption (IBE) in which private key’s source can be traced, i.e., whether the key comes from a private key generator or a user. SM9 is an official cryptography standard of China which defines a practical IBE scheme. In this paper, we construct a practical A-IBE scheme from the SM9-IBE scheme. Our A-IBE scheme has public traceability and is proven secure if the based SM9-IBE scheme is secure. Compared with other A-IBE schemes, our A-IBE scheme has better efficiency in encryption and decryption.

A systematic analysis of identity based encryption (IBE)

Light-weight cryptography is a major research area due to the minimization of the size of the devices utilized for such services. The associated security threats do increase as their applications are more now. Identity-Based Encryption (IBE) with its wide range of cryptographic schemes and protocols is specifically found suitable for low-end devices that have much resource constraint. This work describes various schemes and protocols in IBE. In this paper an analysis of IBE schemes and the various attacks they are prone to are discussed. The future trends are found to be very promising and challenging.

IIBE: An Improved Identity-Based Encryption Algorithm for WSN Security

Wireless sensor networks (WSN) have problems such as limited power, weak computing power, poor communication ability, and vulnerability to attack. However, the existing encryption methods cannot effectively solve the above problems when applied to WSN. To this end, according to WSN’s characteristics and based on the identity-based encryption idea, an improved identity-based encryption algorithm (IIBE) is proposed, which can effectively simplify the key generation process, reduce the network traffic, and improve the network security. The design idea of this algorithm lies between the traditional public key encryption and identity-based public tweezers’ encryption. Compared with the traditional public key encryption, the algorithm does not need a public key certificate and avoids the management of the certificate. Compared with identity-based public key encryption, the algorithm addresses the key escrow and key revocation problems. The results of the actual network distribution experiments demonstrate that IIBE has low energy consumption and high security, which are suitable for application in WSN with high requirements on security.

Efficient identity-based encryption with Hierarchical key-insulation from HIBE

Hierarchical key-insulated identity-based encryption (HKIBE) is identity-based encryption (IBE) that allows users to update their secret keys to achieve (hierarchical) key-exposure resilience, which is an important notion in practice. However, existing HKIBE constructions have limitations in efficiency: sizes of ciphertexts and secret keys depend on the hierarchical depth. In this paper, we first triumph over the barrier by proposing simple but effective design methodologies to construct efficient HKIBE schemes. First, we show a generic construction from any hierarchical IBE (HIBE) scheme that satisfies a special requirement, called MSK evaluatability introduced by Emura et al. (Des. Codes Cryptography 89(7):1535–1574, 2021). It provides several new and efficient instantiations since most pairing-based HIBE schemes satisfy the requirement. It is worth noting that it preserves all parameters’ sizes of the underlying HIBE scheme, and hence we obtain several efficient HKIBE schemes under the k-linear assumption in the standard model. Since MSK evaluatability is dedicated to pairing-based HIBE schemes, the first construction restricts pairing-based instantiations. To realize efficient instantiation from various assumptions, we next propose a generic construction of an HKIBE scheme from any plain HIBE scheme. It is based on Hanaoka et al.’s HKIBE scheme (Asiacrypt 2005), and does not need any special properties. Therefore, we obtain new efficient instantiations from various assumptions other than pairing-oriented ones. Though the sizes of secret keys and ciphertexts are larger than those of the first construction, it is more efficient than Hanaoka et al.’s scheme in the sense of the sizes of master public/secret keys.