Timed-Release Certificateless Encryption

General Certificateless Encryption and Timed-Release Encryption

While recent timed-release encryption (TRE) schemes are implicitly supported by a certificateless encryption (CLE) mechanism, the security models of CLE and TRE differ and there is no generic transformation from a CLE to a TRE. This paper gives a generalized model for CLE that fulfills the requirements of TRE. This model is secure against adversaries with adaptive trapdoor extraction capabiliti...

Improved Anonymous Timed-Release Encryption

We revisit the problem of “sending information into the future” by proposing an anonymous, non-interactive, server-based Timed-Release Encryption (TRE) protocol. We improve upon recent approaches by Blake and Chan, Hwang et al., and Cathalo et al., by reducing the number of bilinear pairings that users must compute, and by enabling additional pre-computations. Our solution compares favorably wi...

A Timed-Release Proxy Re-Encryption Scheme

Timed-Release Public Key Based Authenticated Encryption

In this paper, we formally define a notion of timed-release public key based authenticated encryption (TR-PKAE). In addition to standard time-independent security properties (such as IND-CCA security for confidentiality and ciphertext/plaintext unforgeability), TR-PKAE introduces requirements such as timed-release receiver confidentiality (IND-RTR-CCA), which precludes the receiver from decrypt...

Efficient and Non-interactive Timed-Release Encryption

This paper revisits the important problem of sending a message “into the future” in such a way that no communication is needed between the server and other entities. This problem was recently re-investigated by Blake and Chan who showed a scalable non-interactive solution without considering a formal security model. We fill this gap by introducing a new stringent model tailored to the non-inter...