Toward construction of encryption with decryption awareness ability for cloud storage

Abstract

In cloud platforms, nowadays more and more data owners prefer to first encrypt their personal files and then outsource them to the cloud storage. This however, poses several challenges such as those related to access control and rights. Most previous research results care more about the fine-grained access to the encrypted private files, while little research has concentrated on the following basic question: have the stored ciphertexts been successfully decrypted and when did this happen? Aiming at tackling this problem, we propose a new notion of encryption, namely, public key encryption with decryption awareness ability, which we denote as PKE-DAA. Concretely speaking, PKE-DAA can realize the following: after a ciphertext has been created by the encrypter, once this ciphertext has been successfully decrypted, the encrypter or some other party could be aware of the decryption! To the best of our knowledge, until now there are no such notions or encryption schemes. Own to the recent cryptographic community research result on obfuscation, especially indistinguishable obfuscation, we try to give such a construction in a weak form.We believe that this new primitive has many potential applications, such as against strongest illegal eavesdropping launched by NSA in the post-Snowden era etc.