A few days ago, the paper "Lightweight public key authenticated encryption with keyword search against adaptively-chosen-targets adversaries for mobile devices" by Professor Yang Lu from the cryptographic research group of our college was accepted by CCF Class A journal IEEE Transactions on Mobile Computing (TMC). TMC is a category A journal recommended by CCF in the network direction, and it is also a top international journal in the field of mobile computing.

 

Public key authentication and encryption with keyword search provide an effective way to solve keyword guessing attacks and have received great attention from the cryptography community in recent years. However, the security model used to prove the security of existing public key authentication encryption schemes with keyword search limits the adversary’s attack targets, severely weakens the adversary’s ability, and is inconsistent with reality. This paper proposes an adaptive target selection attack and proves that a public key authentication encryption scheme with keyword search may not be able to resist the attack even if it is provably secure under the existing security model. In response to this problem, the article first established an enhanced security model and gave a formal definition of adaptive target selection attacks; then proposed the first lightweight public key authentication encryption scheme with keyword search, and rigorously demonstrates that the scheme is effective against adaptive targeting attacks from external adversaries as well as malicious storage servers. Compared with existing schemes, the proposed scheme has obvious advantages in both computational cost and communication cost and is suitable for mobile devices with limited resources.

 

This article was completed in cooperation between the cryptographic research group of our college and the cryptographic research group of the School of Mathematics and Information of Fujian Normal University. The first author is Professor Yang Lu of the cryptographic research group of our college. The research work was funded by the National Natural Science Foundation of China and the Natural Science Foundation of Jiangsu Province.

 

[1] Yang Lu, Jiguo Li. Lightweight public key authenticated encryption with keyword search against adaptively-chosen-targets adversaries for mobile devices. IEEE Transactions on Mobile Computing, accepted. DOI: 10.1109/TMC.2021.3077508. Available: https://ieeexplore.ieee.org/document/9423618.