LAUSR

This paper presents AES4SeC, a security scheme fully constructed over cryptographic pairings. The main building blocks of AES4SeC are attribute-based encryption (ABE) and short signatures (SSign), with generalized constructions for the Type 3 pairing. AES4SeC was developed as an end-to-end storage service for hybrid cloud models and integrated to a file-sharing application for scenarios where data owners upload content to the cloud and selectively decide who is able to access that content. An experimental evaluation of AES4SeC was conducted by testing different security levels, recommended key sizes, and cryptographic engine constructions. This led to a wide experimental evaluation in terms of the running times of the primitive operations (encrypt, decrypt, sign, verify) and the space complexity of the ciphertexts, private and public keys, and the signatures. The implementation results revealed the feasibility and flexibility of AES4SeC in real scenarios, whereas a fine-tuning evaluation revealed that the best results in terms of performance and memory requirements are obtained using Type 3 pairings over type F elliptic curves. This is a relevant result because most of the ABE and SSign schemes in the literature are provided for the Type 1 pairing (symmetric) over type A curves, which exhibited poorer results.