Provably Secure Security-Enhanced Timed-Release Encryption in the Random Oracle Model

Cryptographic primitive of timed-release encryption (TRE) enables the sender to encrypt a message which only allows designated receiver decrypt after time. Combined with other technologies, TRE technology is applied variety scenarios, including regularly posting on social network and online sealed bidding. Nowadays, in order control decryption time while maintaining anonymity user identities, most solutions adopt noninteractive server mode periodically broadcast trapdoors, but because these trapdoors are generated fixed server’s private key, many “ciphertexts” related key that can be cryptanalyzed generated, poses big challenge confidentiality key. To work this out, we propose concrete scheme generic security-enhanced (SETRE) random oracle model. In our SETRE schemes, use variable numbers together as generate trapdoors. We formalize definition give provably secure construction SETRE. According experiment, proposed reduces computational cost by about 10.8% compared efficient solution model increases almost negligible storage space. Meanwhile, it realizes one-time pad for trapdoor. large extent, security Therefore, enhances efficiency TRE.