An Efficient Post-Quantum Attribute-Based Encryption Scheme Based on Rank Metric Codes for Cloud Computing

Attribute-based encryption is a valuable technique for ensuring data privacy and confidentiality in the realm of cloud computing. Using this cryptographic primitive, the data owner can securely store and share data within the cloud environment. On the other hand, in recent years, extensive advances have been made in quantum processors, which have raised hopes of solving certain mathematical problems includes factoring integers and computing discrete logarithms of large numbers. The advent of quantum computers has posed a significant security threat to existing cryptographic protocols. The existing post-quantum attribute-based encryption schemes have not satisfied the essential features such as verifiability, user privacy and user revocability, simultaneously. In this paper, we present the first secure, practical and post-quantum attribute-based encryption scheme based on rank metric codes. Our scheme enjoys all mentioned features due to utilization of low rank parity check codes. The proposed scheme provides security against chosen plaintext attacks in the standard model, as well as resistance against reaction attacks as a kind of chosen ciphertext attacks. Moreover, at the 256-bit security level, the key size is about 16.5 KB, with an execution time of around 31.2 ms on a desktop. Our implementation results confirm that the proposed scheme is more efficient than the existing post-quantum and classical schemes.