Multi-Keyword Searchable Identity-Based Proxy Re-Encryption from Lattices

To protect the privacy of cloud data, encryption before uploading provides a solution. However, searching for target data in ciphertext takes effort. Therefore, searchable has become an important research topic. On other hand, since advancement quantum computers will lead to crisis cracking traditional algorithms, it is necessary design schemes that can resist attacks. we propose multi-keyword identity-based proxy re-encryption scheme from lattices. In addition resisting attacks, proposed uses several cryptographic techniques improve efficiency. First, used reduce computation and transmission costs caused by certificates. Second, achieve purpose outsourced computing, allowing server users. Third, provide AND OR operators increase flexibility searchability. Moreover, access structure not based on linear secret sharing (LSSS), avoiding errors LSSS-based decryption or search results. Finally, also give formal security proof under decisional learning with assumption.