Scholars are currently exploring Identity-Based Matchmaking Encryption (IB-ME), which allows senders and receivers to specify identities for decryption, protecting sensitive data in ciphertexts. Our work advances Revocable Identity-Based Matchmaking Encryption (RIB-ME) by adding revocation of decryption rights from unauthorized users. However, most RIB-ME systems rely on the Diffie-Hellman assumption, making them vulnerable to quantum computing threats. Current security models also fail to fully capture adversaries' evolving capabilities, risking unexpected exploits. To address this, we propose a flexible RIB-ME framework, inspired by Wang et al., using a two-tier revocable hierarchical identity-based encryption (RHIBE) approach integrated with post-quantum cryptography. This creates the first quantum-resistant RIB-ME system. We also introduce a detailed security model defining adversaries' strengths and attack patterns over time, enhancing the system's robustness and reliability across various practical scenarios.
Scholars are currently exploring Identity-Based Matchmaking Encryption (IB-ME), which allows senders and receivers to specify identities for decryption, protecting sensitive data in ciphertexts. Our work advances Revocable Identity-Based Matchmaking Encryption (RIB-ME) by adding revocation of decryption rights from unauthorized users. However, most RIB-ME systems rely on the Diffie-Hellman assumption, making them vulnerable to quantum computing threats. Current security models also fail to fully capture adversaries' evolving capabilities, risking unexpected exploits. To address this, we propose a flexible RIB-ME framework, inspired by Wang et al., using a two-tier revocable hierarchical identity-based encryption (RHIBE) approach integrated with post-quantum cryptography. This creates the first quantum-resistant RIB-ME system. We also introduce a detailed security model defining adversaries' strengths and attack patterns over time, enhancing the system's robustness and reliability across various practical scenarios.
In recent years, scholars have developed Identity-Based Matching Encryption (IB-ME), which enables both the sender and the receiver to specify identities, ensuring ciphertext confidentiality only when these identities match. Building on this concept, our work introduces Revocable Identity-Based Matching Encryption (RIB-ME), which incorporates a revocable mechanism to withdraw decryption rights from unauthorized users. Current RIB-ME schemes rely on a variant of the Diffie-Hellman assumption, rendering it susceptible to quantum computing attacks. To address this vulnerability, we propose a generic construction of RIB-ME inspired by Wang et al. Our approach employs two-level Revocable Hierarchical Identity-Based Encryption (RHIBE) and Identity-Based Signature (IBS) and is compatible with post-quantum encryption schemes. This enables the development of a generic construction of RIB-ME and the creation of the first post-quantum RIB-ME through the use of post-quantum constructions.
Abstract Identity‐based Matchmaking Encryption (IB‐ME) is an extension notion of matchmaking encryption (CRYPTO 2019), where a sender and a receiver can specify an access policy for the other party. In IB‐ME, data encryption is performed by not only a receiver identity but also a sender's encryption key. Nevertheless, previous IB‐ME schemes have not considered the problem of efficient revocation . Hence, the authors introduce a new notion of revocable IB‐ME (RIB‐ME) and formalise the syntax and security model of RIB‐ME. In particular, the authors give an effective and simple construction of RIB‐ME in the standard model, whose security is reduced to the hardness of decisional bilinear Diffie—Hellman problem and computational Diffie—Hellman problem. In addition, the authors show two extensions of our RIB‐ME scheme to consider chosen‐ciphertext security and forward privacy.
Matchmaking encryption constructed in the identity-based encryption setting, named identity-based matchmaking encryption (IB-ME), requires both sender and receiver to specify target identity simultaneously for each other for message decryption. The IB-ME schemes can not only ensure the privacy of the sender and the message but also provide authentication for the data source. In order to resist quantum-attacks, we put forward a post-quantum secure IB-ME scheme. Compared with Ateniese et al.'s scheme and Francati et al.'s scheme, our approach eliminates the use of functional encryption, predicate encryption and signature scheme, and only uses a more simple preimage sampling function and an IBE scheme in the way of non-black-box. Compared with post-quantum secure IB-MEs proposed currently, our scheme is the first non-black-box construction based on standard lattice assumptions such as LWE and ISIS.
Identity-based matchmaking encryption (IB-ME) is an advanced encryption scheme that allows both the sender and the receiver to specify their respective identities. We study the notion of hierarchical IB-ME (HIB-ME), which augments IB-ME with delegation capabilities. Specifically, we first formalize HIB-ME and construct it based on hierarchical identity-based encryption and hierarchical identity-based signature. Moreover, as applications of the HIB-ME, we show two chosen ciphertext secure (H)IB-ME constructions for different security levels.
Revocable Identity-Based Encryption (RIBE) can dynamically revoke users whose secret keys have been compromised, ensuring a system's backward security. An RIBE scheme with decryption key exposure resistance (DKER) guarantees the confidentiality of ciphertext during any time period where the decryption key remains undisclosed. Existing RIBE schemes with DKER generate O(rlog(N/r)) ciphertexts for each plaintext message. Redundant ciphertexts impose significant computational burdens on users and substantial communication overhead on the system. To reduce high computation and communication overhead in existing schemes, this paper proposes a dual-key combination trapdoor generation method. Based on the proposed method, an indirect RIBE scheme with DKER is constructed, reducing ciphertext redundancy and obtaining computation and communication efficiency. Firstly, this paper proposes a dual-key combination trapdoor generation mechanism. By constructing an Inhomogeneous Small Integer Solution (ISIS) instance, the Key Generation Center (KGC) generates and distributes short bases to users as their identity keys. Subsequently, based on the constructed ISIS instance, a new inverse ISIS instance is derived. Furthermore, during each time period, KGC generates short bases for all non-revoked users as their time keys. By linearly combining their identity key with the corresponding time key, every non-revoked user can derive a re-randomized decryption key, achieving controlled key derivation. Secondly, based on the proposed method, a Post-Quantum Secure, Lightweight RIBE scheme with DKER (PQS-LRIBE-DKER) is constructed. For every non-revoked user, their identity key and time key serve as their own user secret key and key update, respectively. Controllable key derivation enables indirect revocation of the scheme. By adopting an indirect revocation, the PQS-LRIBE-DKER scheme achieves a single ciphertext per plaintext message, significantly reducing the sender's computational load and the system's communication overhead. Finally, under the hardness assumptions of the Learning with Errors (LWE) and ISIS problems, we prove that the proposed scheme achieves selective identity security in the standard model.
As smart education evolves, there is an increasing need for the cloud-centric management and sharing of student exercise physiological data gathered through wearable devices in the physical education domain. However, challenges arise in achieving authentication for data sources, ensuring the security of sensitive data, and implementing efficient dynamic access control. Traditional cryptographic schemes face limitations in resisting quantum attacks, authenticating data sources, protecting identity privacy, handling dynamic permission changes, and computational efficiency. To tackle these challenges, we put forward a lattice-based Online/Offline Identity-Based Matchmaking Proxy Re-Encryption (OO-IB-MPRE) scheme. The scheme offers post-quantum security assurances grounded in lattice cryptography (under the LWE/ISIS assumptions); incorporates Identity-Based matchmaking encryption (IB-ME) to realize bidirectional identity matching, which not only enables identity authentication for data sources but also safeguards the sender’s identity privacy from exposure to other entities; leverages Proxy Re-Encryption (PRE) to support dynamic management of access control; and combines online/offline encryption to adapt to resource constrained sensors. The security of the OO-IB-MPRE scheme is verified under standard lattice assumptions to meet the security requirements of semi-selective privacy and authenticity. Performance analysis and experimental validation demonstrate that in comparison to existing lattice-based PRE schemes, the devised scheme shows notable advantages in both space and computational overhead. Therefore, the proposed OO-IB-MPRE offers a secure, efficient, and scalable solution for the sensitive health data in smart physical education.